HDCE 124 Tendering

UGANDA TECHNICAL COLLEGE -LIRA
Department of Civil & Building

Engineering
HDCE 124 - Estimating and Tendering Lecture Notes
Estimating and Tendering
Duration: 45 Hours
Module Overview
This module introduces the learner to the process of expressing interest in response to an
invitation for tender with an appropriate estimate. It equips the learner with skills and
knowledge of organisation of construction firms and costing of construction work.
Learning Outcomes
By the end of this module, the learner should be able to:
build unit rates for a project.
prepare a tender document.
Competences
The learner:
prepares a tender and bid document.
bids for work under any method of tendering.
negotiates for construction work.
observes construction firm regulations and organizational structure.
builds up unit rates for labour and materials.
identifies sources of information for pricing and labour constants.
prices and matches construction plant.
carries out evaluation of work.
presents estimates for estimate adjudication and tender submission.
reconciles site cost information with tender rates.
Sub-module 1: Tendering
Prequalification
Open tendering
Selective tendering
Negotiated contracts
Construction firm’s organization
Departments involved in tender preparation 15 Hours
Sub-module 2: Estimation
HDCE 124 - Estimating & Tendering , Civil Department

Uganda Technical College -Lira, Academic Year 2019/2020
Email: alelechris@gmail.com, Mobile: +256-(0)779512306
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Basic wage rate, labour rate build-up, allowance for nonproductive time and wastage
on materials
Analysis of work items on bills of quantities for resource cost components
Sources of cost information for use in pricing, labour constants, considerations in
deciding costs and output constants to use in unit rate build-up. Use of check list for
collecting project information and use of published codes for
Synthesis of unit rates for common work items: earthworks, concrete work,
block/brickwork, formwork, carpentry and joinery, roof coverings, finishing, electrical
installation, plumbing and painting
Pricing, matching and unit rates of construction plant
Net and gross pricing, pricing for profit and attendance, preliminaries, day works,
deemed-to-be included items, prime cost sum, pricing spot items, provisional sum,
project costs and general overheads. Allowing for cost fluctuations in fixed price and
cost reimbursement contracts
Consideration of construction methods and pretender programmes
Presentation of estimate, estimate adjudication and tender submission
Reconciling site cost information with tender rates

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TABLE OF CONTENTS
CHAPTER ONE ................................................................................................................................................................. 5

INTRODUCTION .......................................................................................................................................................... 5
CHAPTER TWO ................................................................................................................................................................ 7
ESTIMATING AND TENDERING. .................................................................................................................................. 7
CHAPTER THREE ........................................................................................................................................................... 17
Open tendering ....................................................................................................................................................... 17
CHAPTER FOUR ............................................................................................................................................................. 27
ALL – IN RATE FOR RESOURCES................................................................................................................................ 27
CHAPTER FIVE ............................................................................................................................................................... 48
CONCRETE WORKS ................................................................................................................................................... 48
CHAPTER SIX ................................................................................................................................................................. 58
BRICK/BLOCK WORK ................................................................................................................................................ 58
CHAPTER SEVEN ........................................................................................................................................................... 62
7.0 CARPENTRY AND JOINERY .................................................................................................................................. 62
CHAPTER EIGHT ............................................................................................................................................................ 65
8.0 FINISHES ............................................................................................................................................................. 65
CHAPTER NINE .............................................................................................................................................................. 68
9.0 PROCUREMENT .................................................................................................................................................. 68

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CHAPTER ONE
INTRODUCTION
The cost of constructing a facility to a client/ owner/ promoter is usually very high and this makes it a
matter of great concern. This includes both initial capital cost and the subsequent operation and
maintenance cost.
The owner is interested in achieving the lowest possible overall project cost that is consistent with
investment objectives.
The capital costs for a construction project are the expenses related to the initial
establishment of a facility which include;
• Land acquisition
• Planning and feasibility studies
• Architectural and engineering design
• Cost of construction (material, equipment, labour, overheads)
• Supervision of construction works (by consultants)
• Construction financing cost (when borrowed from bank)
• Insurance and taxes during construction
• The owner’s general office overheads
• Inspection and testing fee
• Equipment and furnishings not included in construction
The magnitude of each these cost components depends on the nature, size and location of the project as
well as the management organization.
While the construction cost may be the single largest components of the capital cost, other cost
components must not be ignored. For example, land acquisition costs are the major component in urban
areas.
The operation and maintenance cost is subsequent years over the project life cycle include
the following expenses;
• Land rent if applicable

• Operating staff
• Labour and materials for maintenance and repairs
• Periodic renovations
• Insurance and taxes
• Financing costs

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• Utilities
• Owner’s other expenses.
Every stage of construction involves costs right from perception to commissioning and including disposal.
Clients or promoters of the construction industry in the public sector such as the central government
departments, local authorities and public co-operatives (organizations) rely almost exclusively on
competitive tendering to justify the award of tenders.
Clients from the private industry (ies) try to follow the practice of the public sector practices by
advertising in the media.
The success of a project lies on a number of factors which include; accurate estimation of the project
costs, proper project planning, good management.
The process of obtaining the competitive offer for the work involves calculating approximate quantities
and inviting willing contractors to give in their prices of work and this is called Estimation and Tendering.

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CHAPTER TWO
ESTIMATING AND TENDERING.
Most contractors have a director who is responsible for the estimating department and this indicates the
importance of his function.
Construction contractors base tenders on estimate of the cost of the contract for executing the work
described in the contract document. This gives the estimating department a central importance to the
commercial success of the contract.
Definition
Estimating is the process of producing an approximate calculation or judgment of the size, value, cost,
duration of a project, e.t.c.
Estimation is also the prediction of what the key cost of material, land and plant, labour for constructing
a facility will be and a person who carries out estimation is called an Estimator/ Building Economist/
Quantity surveyor.
Importance of estimating
One of the keys to commercial success is the estimator’s ability to estimate to estimate the cost of
construction work and to construct that work to the estimated cost.
In competitive tendering, the tender is based on the estimated cost which represent as much as 90% of
the tender. The other allowances added to are overheads and profits which are smaller to make a
contractor win a tender.
The work connected with the construction of a new structure orwith alterations and additions to an
existing structure is invariably (always) the subject of a contract agreement. The essence of such a
contract is that a builder promises to erect a structure as shown on the drawing and in accordance with
the specification in return to a specific amount of money called contract sum.
A prospective owner cannot give instructions to a contractor to erect a proposed project and accompany
it with an empty cheque to be filled later.
If these practices were to be adopted, the result would be a cost plus account with greater advantage to
a contractor and a great loss to the client.
Virtually, all contracts are obtained by competition between contractors and the subject of builders
estimating consists of the process involved in arriving at the contract sum.

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Contracts without Quantities

These contracts are normally restricted to minor works and the contract documents comprise of
drawings, specifications and form of agreement.
Drawings include plans, elevations, sections and large scale details of proposed work.
The specification is prepared by the architect to supplement the drawings. In the specification, the mixes
of concrete, types of bricks and quantities of any other work are stated and methods of work are
normally stated.
A form of agreement is a legal agreement signed by both parties which states the builder’s contract to
erect the structure in accordance with the drawings and specifications and the client agrees for his part
to pay the contract sum.
Formally contractors would simply study the drawings and specifications and would rely of past data to
quote the contract sum. As competition grew keener, it became difficult to use it.
It became necessary to take off measurement and prepare quantities of work involved.
Applying prices to these quantities, one would come up with the total estimate of the work. The
quantities prepared were not only those of materials but specific elements in the structure like walls,
roof, e.t.c.
Contracts with quantities

These contracts are normally prepared for major works and they are based on BoQ.
The BoQs are prepared by the quantity surveyor on behalf of the client. Several copies of BoQs are
prepared and sent out to the contractors who are interested in doing the work to enter in their prices or
rate for the execution of the work.
When the contract is signed, the BoQ and prices become part of the contract agreement and will be used
in preparation of the final accountability and in the settlement of variations.
The provision of BoQ leads to accurate tendering as all those tendering have identical conditions on
which to work and this considerably reduces the cost of estimating.
Functions of an Estimator
The primary function of an estimator in construction work is to properly price the unit rates in a BoQ,
calculate the estimated cost of preliminary items applicable to the contract being priced and to prepare
the estimate for submission to managers for adjudication into a tender.

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Parties involved in Estimating and Tendering
i. Client’s/ promoter’s staff or their professional representatives.

ii. Consultant
iii. Contractor; planners, plant managers, site management staff.
iv. Subcontractors and nominated suppliers.
Terms used in Estimating and Tendering
i. Own builder’s work

This is work carried out by builder’s own operatives; employ people to work for you e.g National Housing
employs masons, carpenters.
ii. Own subcontractor’s work

Is the work carried out by subcontractors on behalf of the owners. The estimator is sometimes
responsible for obtaining quotations from subcontractors who are capable of carrying out the work in
allocated period for the trade and to the required quality.
iii. Nominated subcontractor’s work

This is the work executed by subcontractor chosen by the architect. They are normally selected for
specialized works like installation of a lift.
iv. Nominated supplier

Supplier selected by the Architect/ client to supply particular materials (special material e.g a lift).
v. Preliminaries
When preparing a tender for a contract based upon BoQs, there are certain items of expenditure usually
termed project overheads that cannot be satisfactorily distributed among unit rates hence some of the
items are calculated as lump sums and they are placed in the preliminary bill e.g general foremen, site
offices, storage sheds, operating costs, plant, tools, temporary roads, rubbish removal, overtime.
vi. Profits
Is the amount of money added to the net estimated cost as a return on investment capital considering
competition and source of capital.
vii. Accurate Bills of Quantity

A large part of the work of the quantity surveyor is the preparation of a BoQ and its accuracy depends on
the availability of full particulars of work required.

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The fuller and more detailed the Architect’s drawings, the better the chance of an accurate bill with a
minimum of extras arising during the progress of the works.
viii. Overheads
These include payment of salaries to the head office staff, head office operating costs and similar items
which are necessary for the administration of the contract and which are not normally charged directly to
the actual cost of work.
ix. Approximate BoQs

These are used at times when sufficiently full information cannot be given to enable an accurate BoQ to
be prepared. It may be a foundation contract in which the depth of excavation and thickness of contract
cannot be ascertained until the bearing surfaces are exposed.
Nevertheless, it may be known fairly accurately in advance of what items are likely to occur in
measurement. A bill can therefore be prepared which though with approximate quantities can be used
for tendering subject to a complete measurement of the work as executed and revaluation at the tender
rate. For example, if volume of excavation increased, the quantity is charged but the rate remains the
same.
x. Schedule of Prices
Information may be so scanty or at times so short that not even an approximate quantity can be given. In
such a case, a schedule of probable/ possible items can be prepared giving descriptions similar to those in
a BoQ but without quantities.
There is difficult in making comparison of tenders with such schedules as there are no quantities.
Comparison however can be made between the major items.
xi. Prime cost contracts

Information may be so lacking that an adhoc (unplanned/ emergency) schedule of prices may not be
prepared and no standardized schedule may be considered suitable. In that case, a form of prime cost
contract is used; i.e one where a contractor is reimbursed his proven cost and paid an additional sum to
cover profits and overheads either as a percentage on that cost or a fixed fee. xii. All-in contract
(Turnkey/package deal)
With this form of contract, the contractor undertakes the whole of the services required from design so
dispensing with the independent architect, consultant and quantity surveyor. Usually barter trade is used
as payment terms.
xiii. Estimate Adjudication

After estimators have done their calculation of the approximate cost of the project including profits and
overheads, the work is presented to the management for adjustment and this is the process of
converting an estimate into a tender.

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It involves adjusting the estimates downwards or upwards or maintaining the same figure to prepare the
tender document.
xiv. Consultant’s Estimate

This is an average price from past record or the design estimate.
xv. Contractor’s Estimates

These are based on facts calculated from the proposed work.
xvi. Cost engineering

Is an area of engineering practice where engineering judgment and experience are utilized in the
application of scientific principles and techniques to the problem of cost estimation, cost control and
profitability.
ASSIGNMENT (READ ABOUT)

Write short notes on the following terms
All-in rates for resources

All-in labour rates
Estimated costs
Historical costs
Estimating Process
1. Acquisition of documents (plans, specification, BoQs, Form of agreement, Conditions of contract)

upon acquiring information from client through newspaper, internet, friends.
2. Decision to tender considering resources, manpower, profitability, location.
3. Programming the estimate.
4. (a) Collection and calculation of cost information through site visits (labour, water, raw materials,
power).
(b) Decision to tender after visit.
5. Project study.
6. Preparing the estimate having details of work and contract sum.
7. Calculation of project overheads and establishment overheads plus contractor’s profits.
8. Production of estimator’s report.
Note:
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The process of preparing a tender document follows the estimating process but after production of the
estimator’s report, the following two steps are done:-
1. Presentation of the estimator’s report to directors to convert it to a tender.

2. Submission of tender.
Techniques / Methods of Estimating
i. Unit rate estimating technique

Is one which is based on the traditional BoQs approach where the quantities of works are defined and
measured in accordance with the standard methods of measurement.
ii. Operational estimating technique

This is a complex procedure based on calculating the total quantity of work involved in an operation ( e.g
excavation and concreting) and estimating the total elapse time of the operation in weeks and combining
this with the selected resources (materials, labour and plant).
This method of calculation if favored by estimators involved in plant dominated activities e.g excavation
and concrete works.
Other estimating techniques
o Global method – It is a crude estimating method which relies on the existence of data for similar
projects assessed purely on a single characteristic such as the size, capacity or output.
o Factorial technique – It is widely used on process plants e.g water works where the key
components can be easily identified and priced and all other works are calculated as factors of
this component.
o Spot (gash) technique s– Are direct cost estimates which are not based on calculation but based
on experience.
o Man-hour technique – It is a labour based method. Work I s broken down into unskilled, semi-
skilled and skilled according to the required standards. o Empirical cost interference and
production functional approach.
Types of Cost Estimates for Tendering

These include the following:
o Pre-tender cost estimate (design estimate) – screening,

preliminary, detailed, engineer’s, estimate
o Tender/bid estimate o Control estimate

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a) Pre-tender cost estimate (design estimate)

In planning and design stages of a project, various design estimates reflect the progress of the design.
A screening or order of magnitude estimate is one which is usually made before the facility is designed
and must therefore rely on the cost data of similar facility built in the past.
A preliminary or conceptual estimate is one which is based on the conceptual design of the facility at the
state when the basic technologies for the design are known.
A detailed or definitive estimate is one made when the scope of work is clearly defined and the detailed
design is on progress so that the essential features of the facility are identifiable.
The engineer’s estimate is one based on the completed plans and specifications when they are ready for
the owner to solicit bids from construction contractors.
In preparing the estimates, the design professional will include expected amounts for the contactor’s
overheads and profits.
b) Bid/ Tender estimate

A bid estimate is one submitted to the owner either for competitive bidding or negotiation consisting of
direct construction cost including field supervision, plus a markup to cover general overheads and profits.
The direct cost of construction for bid estimates is usually derived from a combination of the following
approaches: sub-contractor’s quotation, quantity take-off, construction procedures.
Contractor’s bid estimate often reflects the contractor’s desire to secure a job as well as the estimating
tool at its disposal.
If a contractor believes that the chances of success are not high, he puts in the least amount of possible
effort in making a cost estimate since always a lowest bidder will be the winner of the contract in most
bidding contests.
c) Control estimate
For monitoring the project during construction, a control estimate is derived from available information
to establish;
• Budget estimate for financing

• Budgeting cost after contracting but prior to construction
• Estimated cost of completion during the progress of construction
Both the owner and the contractor must adopt some baseline for cost control during the construction.

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For the owner, the budget estimate must be adopted early enough for planning along with financing the
facility. The detailed estimate is often used as a budget estimate as it reflects the project scope. The
budget cost must always be revised periodically as is necessary either because of change orders initiated
by owner or unexpected cost overrun.
For the contractor, the bid estimate is used as a budget estimate which will be used for control purposes
as well as for planning construction financing. Revise the budgeted cost periodically to reflect the
estimate cost to completion as well as to ensure adequate cash flow.
Importance of each of the above estimates to different parties in any construction project To
Owner
Design/Pre-tender Cost estimate Bid/ Tender Estimate Control estimate
Assessing best alternative Choosing best bidder Come up with control budget
To Contractor
Understand scope of work Estimating tool Come up with control budget
Determine resource demand Come up with best bid Carryout cost analysis
Execute work as per schedule
To Consultant
Choosing appropriate technology To select best bidder Valuing work done according
according to quotations to to specifications.
Design different facility components requirements of facility
Allocating prices as drawn
EXAMPLES OF ESTIMATING USING UNIT RATE TECHNIQUE

One
Compute the cost per tonne for the provision and fixing a 16mm diameter reinforcement.
Data
Material purchase cost 1923077 per ton

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Wastage 5%
Tie wires and spacers 2%
Cutting and bending labour 15hrs per ton
Fixing rate labour 20hrs per ton
Bar bending machinery within on-site cost
Site transportation within on-site cost
Labour for steel fixer 3000 per hr
Solution
Purchasing ……………………………………………………… 1,923,077 per ton
Wastage of 5% of purchase……………………………… 96,154/
Add 2% of purchase for spacers and binding wires………… 38,462/

Total ……………. 2,057,693/ per ton
Labour (15+20) x 3000………….. 105,000/ per ton
Total ……………. 2,162,693/per ton
Add 20% profits and overheads ………………………... 432,539/
Total……………. 2,595,232/ per ton
Two
Compute the cost of dredging per CM if a total of 3,000,000CM of material is to be dredged from a
harbour basin and deposited off on land. From the programmed of work, dredging, reclamation and slope
protection extends over a duration of 6months.
Data
Hire rate for dredger $100,000 per month
Hire rate bulldozer $75,000 per month
Fuel cost estimated at 5% of the equipment cost (the fire rate)
Machine operator is paid $6.5 per hour for an average of 70hrs per week.
Bankman is paid $5.5 per hour for an average of 70hrs per week.
Solution

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Dredging
Cost of dredger hiring for 6months……………..$100,000x6……… $600,000
Fuel cost………………………………0.05x$600,000…………….. $30,000
Cost of labour………………………. $(6.5+5.5)x70x26…………… $21,840
Total cost of dredging $651,840
Cost of disposal
Cost of bulldozer hire ……………………….$75,000x6………….. $450,000
Fuel cost…………………………………….0.05$450,000……….. $22500

Cost of labour ………………………………$(6.5+5.5) x70x26………. $21,840
Total cost of disposal $494,340
Total cost of dredging and material disposal $(651,840+494,340)……………. $1,146,180
Cost per CM 1146180/3,000,000 = $0.382 per CM
Assuming 20% of profits and overheads giving $0.08 per CM,
The total cost per CM $(0.38+0.08) = $0.46

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CHAPTER THREE
TENDERING
This is the submission of a quotation.
A quotation is a price that a firm charges to offer a good or service.
Taking a decision to tender

Against corporate plan, senior managers will take the decision to bid for a specific contract.
Decisions are taken;
During the pre-selection stage

After careful examination of the contract documents
After the estimate has been prepared and tender is ready to submit
Factors considered while taking the decision to tender
Potential contribution of the contract to the company’s turnover in a particular sector; the overheads
recovered and the anticipated profits
The likely demands of the contract on the company’s financial resources
The company’s resources available e.g the working capital and human resources
Type of work
The location of the project
The type of client
Contract deal
Tendering Procedures or Methods
Open tendering
The procedure is to advertise in the press inviting any firm that wishes to do so to submit a tender; bid or
offer. The advertisement will give an outline detail of the type of work, the scale program and any other
key features.
Any interested firm applies for the tender documents and there are usually no formalities other than a
little fee for the tender documents and discourage those who are not interested in the job or idle
curiosity. This system is commonly used by public bodies. e.g local governments, public services although
it is also used by private institutions.

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It’s usually stated in the advertisement and in the tender document that the employer does not bind
himself to the lowest offer as the advertisement does not bid the employer in any way but it is merely an
invitation to person or firms to make an offer and any offer made should be unconditionally accepted.
Merits
• It gives a chance of tendering to a firm which wishes to dos so.

• Since there is no restriction, there can be no chance of favouritism.
Demerits
• There are a large number of tenders to evaluate hence much time and money wasted.
• There is normally pressure to accept low tenders.
• There is a high cost on the contractor’s side as he tenders for very many jobs and wins nothing or
only one.
• There is difficult in selecting the right firm.
Selective tendering
Here the procedure is to select a limited number of firms known to the architect/client and invite them to
tender and this procedure is mainly used by private firms or institutions.
Selection should be made sufficiently early for firms to be asked whether they will be willing to tender at
the required time. The criteria to be employed in drawing up the list of the selective firms will depend to
some degree on the character of the project as well as its size, location. Also consider equipment
available, standard of workmanship by firms, size of payroll, business record, and number of strikes
within the company, financial stability, and real willingness to tender.
Merits
• It’s possible to select the most competent firm.

• Since tenders are few, there is time and cost saving.
Demerits
• The firms are sometimes overloaded as they may be reluctant to decline some tenders at the
time they have a lot of jobs.
• It breeds/ brings favoritism and corruption.
• There is always reluctance to strike off incompetent firms from the list.
• Newly formed firms that are competent cannot tender for the job.
• There is always higher quotation than obtainable by open tendering as there is less competition.

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Single tendering
There may be circumstances in which only one firm will be able to satisfy the criteria for selection.
This likely happens when specialist or nominated contractors e.g in installation of lifts, gas pipes works,
supply of some selected materials are involved.
Merits
• It is cheap to evaluate the tender.

• The firms with tested results are employed.
Demerits
• It’s usually expensive as a single contractor tenders.

• It’s somewhat undesirable and perhaps an un health state of affairs and can be embarrassing is
un satisfactory tender is received.
Serial tendering
Is a premeditated (deliberate) form of extension and comes essentially into the category of tendering
rather than negotiation. It applies where there a series of similar schemes which are to be carried out
over a period of time within the same area and permitting the phased utilization of the site organization
and plant e.g construction of schools.
It is useful for main contracts and can also secure the benefits of the increased size of order and
production run for component contract and specialist site installation work which become subcontracts
to a series of main contracts.
An example is where a contractor is invited to tender for one building e.g a school on the understanding
that the successful firm will build several schools at the agreed rate.
Merits
• It encourages keener prices than would project for single project.

• Experience gained on the earlier project will be useful later on.
Demerit
• Rapid inflation tends to curtail this type of contract.

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Negotiated tender
This is usually used for construction of a very difficult nature of work, where the magnitude of the
contract may be unknown at first or where early completion is most important, or where continuation or
repetition of an existing contract is considered desirable.
For this contract, there is usually no time to wait for drawings and BoQ to be prepared. One firm is
selected and negotiated with.
Merits
• It’s time saving as no documents/ drawings are prepared.

• It offers a more rational price basis for the contracts perhaps stimulate design improvement.
Demerits
• It’s hard to satisfy the test of the public accountability.

• Suffers from higher cost due to lack of competition.
Prequalification
Is where a selection of capable firms takes place before submission of the tenders or quotations.
Merits
The same as for selective tendering.
Demerits
The same as for selective tendering except leaving out of new firms.
PRICING OF TENDERS
Tenders are prepared on the basis of net or gross pricing.
1. Net pricing
Here, only the net site cost is included when building up a basic unit rate for an item; the quantity (ies)
are extended to their rates and totaled.
Profits and overheads are calculated as lump sum based on total net site cost and added to net site cost
to give a tender figure.

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Merit
Calculation of profits and overheads can be reduced to one or two operations thus giving a more
accurate tender.
Demerit
Automatic increase in the amount included for general profits and overheads do not take effect if
variations for addition are made.
2. Gross pricing
Net site cost unit rates are calculated and a percentage is added to each unit rate to cover the general
profits and overhead.
Merit
If variations occur on the contract, they are priced at the rates inserted in the BoQ which subsequently
increases the amount with variations for addition work. This is advantageous to the contractor.
Demerit
There is a greater margin of error when the percentage is added to each unit rate to cover profits and
overheads.
TENDER DOCUMENTS
The Institution of Civil Engineering (ICE) Chapter 6 clause 5 states that “the several documents forming a
contract are to be taken as mutually explanatory (serving to explain)” there is no order of preference, the
engineer will have to resolve any contradictions and under the ‘contra proferentem’ rule contradictions
will be construed against the employer (who drew up the contract)
The tender documents will comprise of;
a. Instruction to bidders.
b. From of tender.
c. Conditions of contract.
d. Form of agreement.
e. Drawings.
f. Specifications.
g. BoQ.
h. Other documents e.g Soil data, specific conditions.
Instruction to tender
This will include;

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Place, date, time by which tenders must be returned.

Methods of dealing with queries.
How qualified tenders will be dealt with.
Provision for site visits.
Documents to be submitted with a tender.
Methods of dealing with errors.
Form of tender
This satisfies that there is an offer by the contractor and acceptance by the employer.
This has no price; this means a variation order is not required for changes in quantities. Its appendix gives
defects correction period, whether there is need for performance bond, minimum amount of third party
insurance, start date and completion date, liquidated damaged and retentions.
Conditions of contract
These do two things:
Sets out the contractual responsibilities and liabilities.

Establishes the administrative arrangement.
Form of agreement
This needs only to be signed if the employer wants to enter into a sealed contract otherwise; a letter of
acceptance is all that is needed.
Drawings
The tender documents will not usually be all that is needed to complete the works but they should be as
comprehensive as possible to ensure that the contractor’s rate truly reflect the nature and extent of the
work. These include among others; plans, sections, elevations.
Specification
In ICE6 contracts, the specification is an independent contract document provided to supplement the
drawings by giving missing information like quality of materials and states general characteristics
common to all works in the BoQ.
Bills of Quantities
These should be drawn up in accordance with Civil Engineering Standard Methods of
Measurements part 3 (CESMM 3) or any agreed standard method of measurement in the country.

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Purpose of BoQ
A BoQ Consists of a schedule of the item of work to be carried out under the contract with quantities
entered against each item. The quantities inserted in a bill are normally approximate.
i. Enables the contractor tendering for a job to price on the same information.
ii. Gives itemized lists of the elements of the building with a full description and the quantity of
each item, which assist the building owner and successful contractor in assessing materials and
labour requirements for the job.
iii. Used in the valuation of work done at any time during construction of the works and completion.
iv. Provides a basis for the valuation of the variations occurring during works.
v. After being priced, provides a basis for cost planning and cost analysis.
vi. Enables contractor to check on his accuracy and order for materials for different works.
Process of preparing a BoQ
Taking off
Is where dimensions are scaled or read from drawings and entered in a recognized form specially ruled
paper called ‘dimensioning paper’
Working up; this comprises;
a) Squaring the dimensions, transferring the resultant length, areas and volumes to the abstract,
where they are arranged in a convenient order for billing and reduced to the recognized units of
measurement.
b) The billing operation, where the various items of work making up the complete job are listed in fill
with the quantities involved in a suitable order under section headings.
The term ‘quantities’ is the estimate amount of labour and materials required in the execution of various
items of work and together, these items give the total requirements of the building contract.
Functions of the Building Economists or Quantity Surveyor

Besides preparing a BoQ, they also perform the following:
Advise on what a project would cost.

Advise on what size and standard of structure an be erected for any given expenditure.
Co-operate with designers to ensure that a building is erected within an approved expenditure.
Advise on the tendering procedure and contractual arrangements.
Exercise control during the construction so that the cost is not exceeded without authority.
Determining compensations of those affected by the project.

23
At with the architect or engineer to ensure that the final provisions of the contract are properly
interpreted and applied so that the client’s financial interest is safe guarded and the builder is
paid a proper price for the work.
Tender period
6 weeks is common, the range is from 4 – 12 weeks. Queries and replies are dealt with in this time
formally.
Analysis of tender
No tenders should be opened before the submission closing time and date and should all be opened at
same time. All tender’s name and bill total should be written down and witnessed by the parties present.
First check is for arithmetical errors, and contractor’s tendering rates.
Acceptance
Prior to acceptance, it’s not common to meet the contractor to clarify points on the tender. A letter to
the contractor accepting the tender will form a binding contract.
Bid bond/ bid security

This is the money paid by the bidder on submission of the tender document. It shows the seriousness of
the contractor to do the job.
Bid withdraw
This can happen after the contractor has obtained information about the job and realizes that he cannot
afford to carry out the work.
Before opening of the bids, the bid security will be returned to the bidder.
After bid opening, a successful bidder may not withdraw his bid unless the bidder can prove by clear and
convincing evidence that a non-judgmental mistake was made in the original bid.
Performance bond
This is the security paid by the contractor to show that he will execute the work appropriately according
to the contract details. This money is refunded to the contractor on completion of the contract.

24
UGANDA TECHNICAL COLLEGE -LIRA

Department of Civil & Building
Engineering
HDCE 124 - Estimating and Tendering
YEAR FOUR: ASSIGNMENT NO.2 Dated: MARCH 02, 2019
INSTRUCTIONS
• Final Submission date for hardcopy: March 16, 2020 - (1600hrs)
• Final submission date for soft copy: March 16, 2020 - (2359hrs)
• This assignment should be typed using Arial or Times New Roman with a font within
a range of 10 to 12 points. The main body of the work should be in 1.5 spacing.
• The overall word length for this assignment should be in a range of 3000 – 4000
words. You must state the total number of words used at the end of your assignment.
Question One
Method statements are written descriptions of how activities of work will be carried out;
they usually deal with the use of labour and plant in terms of types, gang sizes and
expected outputs. Appraise the reasons why method statements are prepared during the
tender stage. (20 marks)
Question Two
A tenderer is expected to make enquiries for prices of materials associated with the
proposed construction project in order to come up with a competitive bid. Many
construction companies have a standard form of enquiry for suppliers. Explain the
composition of a typical enquiry form that a bidder will issue out to his suppliers for pricing.
(20 marks)
Question Three

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A construction company whose capital is fully committed may rely solely on hired plant,
but as the business grows and workload increases, the contractor may decide on outright
purchase of specific plants for the business. Explain the considerations the contractor is
likely to put into account before purchase of the plant. (20 marks)
Question Four
As an Estimator, you are tasked to analyse unit rates that will be applicable to a project
with massive excavation works; Discuss the factors that will affect your rates and choice
of either hand or machine for the excavation works. (20marks)
Question Five
Appraise the relative merits and pitfalls for hiring plant versus purchasing / owning plant.
(20marks)

26
CHAPTER FOUR
ALL – IN RATE FOR RESOURCES
An all-in rate refers to the total cost/price of executing a unit piece of work. In included the cost of
labour, plants, materials, profits and overheads.
Resources (land, labour, capital, entrepreneurial activities) refer to the valuable elements required for
the accomplishment of a given piece of work/task.
Analysis of Rates
This is the process of determining the rate of an item or work/ supply of the materials. A reasonable
profit, usually 10%-20% for the contractor should be included in the analysis of rates.
Factors affecting the analysis of unit rates

These are sometimes called components/constraints.
Materials – their quantities required for completion of an item are known from their specifications and
the prices are dependent on the market conditions varying from place to place.
Labour – the amount of labour required depends on the average of past works. Since capacity to do work
and wages of labour vary from place to place, the cost of labour is a variable factor; hence, proper
studying of efficiency and wages of labourers before start of rate analysis is required.
Site conditions – difficult site conditions will usually invite slightly higher rates.
Specifications – with very rigid specifications of work, the rate will be higher.
Conditions of contract – with very strict conditions, a higher rate is invited and vice versa.
Quantum of work – if the contract is big, the rates of items are likely lower.
Special equipment – if special equipment is required for certain items, the rate of work is bound to be
higher as the cost of equipment/rent cost is added on the rate.
Place of work – if the site is situated in a highly congested area, it will not be possible to take the
materials directly on site hence, higher rates.

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Profits to the contractor

Miscellaneous – factors like time of project completion, climatic conditions, and reputation of the
contracting agency also affect the rate of items.
Purposes of carrying out rate analysis
o To compute the current actual cost per unit of work at the locality.
o To examine the viability of the rates offered by the contractors.
o To calculate the quantity of materials and labour strength required for project planning.
o To fix up labour contract rates.
o To fix profits and overheads.
How to fix up rates per unit of item

The following 5 sub heads are to be examined and the summation of these is the rate per unit of an item.
o Quantity of materials and their cost.
o Labour costs.
o Cost of equipment and tools.
o Overhead or establishment charges.
o Contractor’s profits.
LABOUR
Labour refers to workers who provide physical effort for the execution of particular works/ physical
efforts provided by work force.
Labour output is the most uncertain part of a unit rate. It can vary considerably depending upon the skill
and output of the operatives, the site organization, weather conditions and other factors outside the
control of the contractor.
An estimator should calculate the hourly cost to the builder of the skilled and unskilled labour which will
be employed on the contract if the tender is successful, and this is classified as the build-up of labour
rate.

28
Factors considered in coming up with labour rates
Basic rate of pay in accordance with the working rule agreement.

Third party insurance and federation payments – autonomous (self governance). Guaranteed
time inclement (unpleasantly cold/wet) weather.
Training levy.
Graduated pension contribution.
Sickness benefit.
Holiday with pay contribution at current rate.
National insurance and redundancy (standby) contribution at current rate.
Tool allowance.
Travelling expenses.
Extra payments of discomfort, extra skill, intermittent (specialist) responsibility.
Trade supervision.
Percentage addition to cover the extra cost brought about by the operative working fewer hours
than expected.
Overtime.
EXAMPLE OF BUILDING UP LABOUR RATES

Computations are made basing on a week of 5 days, 8 hours a day giving 40 hours a week.
Consider a year of 50 weeks.
Consider the table below

Unskilled Skilled
Basic pay per day 8000/= 15000/=
Third party as a %age of basic 2.5% 2.5%
Guaranteed time as a %age of basic 2% 2%
Graduated pension as a %age of basic 2% 2%
Sickness benefit as a %age of basic 0.5% 0.5%
Holiday with pay contribution (annually) 200,000/= 350,000/=
National insurance & redundancy (annually) 128,000/= 128,000/=

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Public holiday (annually) 120,000/= 120,000/=
Training Levy per week 5,000/= 10,000/=
Calculations
Unskilled
Basic pay………………………………………………………8000/8 =1000*40 = 40000/=
Third party……………………………………………………..0.025*40000 = 1000/=
Guaranteed time………………………………………………. 0.02*40000 = 800/=
Graduated pension…………………………………………….. 0.02*40000 = 800/=
Sickness benefit………………………………………………..0.005*40000 = 200/=
Holiday with pay contribution…………………………………200,000/50 = 4000/=
National insurance & redundancy…………………………….. 128,000/50 = 2560/=
Public holiday…………………………………………………..120,000/50 =2400/=
Training Levy…………………………………………………………………………… =5000/=
Total per week =56760/=
Unskilled rate per hour 56760/40 =1419/=
Skilled
Basic pay…………………………………………………………15000/8 =1875*40 = 75000/=
Third party ………………………………………………………..0.025*75000 = 1875/=
Guaranteed time…………………………………………………..0.02*7500 = 1500/= Graduated pension

……………………………………………......0.02*4000 = 1500/=
Sickness benefit………………………………………………….. 0.005*7500 = 375/=
Holiday with pay contribution…………………………………….350,000/50 = 7000/=
National insurance & redundancy…………………………………128,000/50 = 2560/=
Public holiday………………………………………………………120,000/50 =2400/=
Training Levy ………………………………………………………………………........=10000/=
Total per week = 102,210/=

30
Skilled rate per hour 102,210/40 =2555.256/=
Extra payments
Extra payments for discomfort or risk, continuous extra skill or responsibility, intermittent responsibility,
and similar items should be added to the built up hourly rate, in accordance with the working rule
agreement.
Overtime
The estimator must decide the amount of overtime which is to be included in the labour rate for the
contract being tendered for.
Fluctuation
When the fluctuation clause is included in the conditions of contract, it is necessary for the estimator to
ascertain whether his built up rates are to be on current rates of wages if known increases are to be
included. If known increases have to be included, they are dealt with in a similar manner to the section
‘firm price tender’
Firm price tender

When the project tendered for has had the fluctuation clause deleted from the conditions of the
contract, it’s necessary for the estimator to add or omit all known increases or decreases in labour after
the date of tender and during the estimated contract period. The estimator also needs to make
allowance for further anticipated variations in labour cost over the period.
Factors that lead to variation in labour rate
Variation in attitudes, culture, e.t.c of the individuals.

Location of work e.g height; underground works, high levels.
Weather conditions.
Workmanship expected.
Level of supervision.
Site organization.
Skills of workers.
Factors that affect labour rates
Supervision.
Overtime.
Holidays.
Training levy.
Locality.

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Example on how labour rates are affected by supervision

Consider skilled labour
Assume 8 brick layers who are able to lay 4m2 of a 225mm thick wall in one hour.
One supervisor.
Assume 8 working hours a day.
Use
Labour 15,000/= per day……………………………………………………..1875/= per hour
Supervision 24000/= per day…………………………………………………..3000/= per hour
Cost of 8 brick layers per hour = 8*1875………………………………………15,000/=
Cost of supervision per hour = 3000…………………………………………….3, 000/=
18,000/= per hour
Cost of labour rate per hour (labour rate) 18000/8……………………………….2250/=per hour
Labour rate = 2250/= with supervision
=1875/= without supervision
Difference = 375/=
Example on how labour rates are affected by overtime
Consider from Monday to Friday working for 8hours a day which gives 40hours a week.
Consider also working for additional one hour per day from Monday to Friday and working for 6hours on
Saturday.
Consider the factor for over time as 1.5.
Given a labour rate of 1875/= per hour for a worker.
computations
Total working hrs a week with overtime = 40 + (5*1.5) + (6*1.5) ……………..56.5hour a week
Actual working hours a week = 40+5+6…………………………………………51hrs a week
Total amount per week = 1875*56.5…………………………………………105937.5/= a week
Cost of productive hrs (labour rate) = 105937.5/51…………………………..2078/= per hour
Effect of over time =2078 – 1875……………………………………………..203/=

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Note:
Where labour rates cannot be built up due to inadequate time, labour rates can be got from; i.
Past records of work. ii. Current rates from sister companies considering inflation
Multiply past rates by a factor (1+f)n where n is the number of years that have elapsed from the time of
tendering and f is the average inflation rate.
MECHANICAL PLANT
The estimator must decide on the type of machines to be used and their respective sizes before pricing
any of the items involved.
The type of machine will depend largely on; amount of work, nature of work or material to be excavated,
weather conditions, time frame.
Excavation plants, concrete mixers, rollers or even transport vehicles are usually charged on site at an
hourly hire rate based on a normal working week.
Any time worked over the number of hours on hire agreement is charged extra also travelling time
expenses to and from the site.
Methods of acquiring a plant
By purchasing
By hiring
By leasing
Depreciation of machines
Plants suffer wear, tear, and physical deterioration in constant use. Invested capital must be recorded to
remain in business.
Causes of depreciation
o Age
o Introduction of newer most efficient plant
o Lack of maintenance
o Nature of work
o Wear and tear
Methods of calculating depreciation costs

Methods for calculating depreciation costs were evolved through tradition and permitted by the taxation
authorities for the purpose of retention of the sums accumulated.

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a) Straight line depreciation method

Here, the total depreciation sum (total capital spend on acquiring it minus its estimated salvage/scrap
value at the end of its useful life) is divided by the estimated useful life of the asset.
Interest rate is not taken into consideration by convention and for the sake of simplicity.
Example
Consider purchase of a tipper lorry at £16,000. The ripper lorry has a life of 4years and salvage value of
£4,000.
Solution
The depreciation cost =£(16,000 – 4000)/4 =£3000.
Year Amount to recover (£) Net book value (£)
0 0 16,000
1 3000 13,000
2 3000 10,000
3 3000 7,000
4 3000 4,000
b) The declining balance method

This is also called diminishing balance method/ constant percentage book value method. A certain
percentage is fixed of the cost of the equipment to be recovered per year.
The percentage depends on;
o Cost of capital
o Life of the equipment
o Inflation
o Competition
o Profit
Example
34
Consider purchase of a dump truck at £16,660 with useful life of 4years. Use the method of declining to
compute the yearly amounts to recover if the fixed percentage to recover is 30 and the salvage value is
£4,000.
Year Beginning of year (£) End of year (£) Yearly amount to be recovered (£)
0.7P 0.3P
1 16,660 11662 4998
2 11662 8163.4 3498.6
3 8163.4 5714.4 2449
4 5714.4 4000 1714.4
Salvage, S = P(1-r)n
Where n = no of years (period) r
= fixed depreciation rate
P = initial cost.
c) Sinking fund method

Here, the cost of any capital is ignored until such a time when the accumulated sum equals to original
sum borrowed and the redemption of loan takes place.
P(1+ i)n
Depreciable cost R = i
(1+ i)n −1
Where; i = interest on capital.
n = number of years.
Compute for R using i as the interest on capital, add running cost as a percentage of R, then add profits
and over heads.

35
Example
Consider purchasing an excavator at UGX 300m with a life of 3years and a resale value of UGX100m.
Interest on capital is 20%, running cost is 10%. Profits and overheads are 20%. Calculate the cost per hour
of the equipment assuming 8hours a day, 5 days a week and 50 weeks a year.
Solution
P(1+ i)n
Using R = i
(1+ i)n −1
300(1+ 0.2)3
R= 0.2 = 142.4m
(1+ 0.2)3 −1
Adding running cost =1.1*142.4 =156.64m
Adding profits and overheads = 1.2*156.64 =188m
Therefore cost per hour = 188,000,000/2000 = UGX 94,000
d) The sum – of - digits method.
In this method, the digit numbers representing each year of operation of the plant are added together.
The depreciation charge for each year is taken as the depreciable sum multiplied by the ratio of the
reverse year’s number to the total added digits.
Example
If a truck is purchased at 30m shillings and the resale value is 10m at the end of the 5th year, the digits are
1,2,3,4 and 5. Determine the depreciation charge.
Solution
Total digits = 1+2+3+4+5 = 15
Depreciable sum = 30 – 10 = 20m
Depreciation in the 1st year = (5/15)*20 = 6.7m
Book value at the beginning of 2nd year = 30 -6.7 = 23.3m
Depreciation in the 2nd year = (4/15)*20 = 5.3m
Book value at the beginning of 3rd year = 30 -5.3 = 24.7m

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Depreciation in the 3rd year = (3/15)*20 = 4m
Book value at the beginning of 4th year = 30 -4 = 26m
Depreciation in the 4th year = (2/15)*20 = 2.7m
Book value at the beginning of 5th year = 30 -2.7 = 27.3m
Depreciation in the 5th year = (1/15)*20 = 1.3m
Factors that affect the cost of a plant
Inclement weather
Lack of supervision
Inexperienced operator
Lack of maintenance
Use of inappropriate machine (poor selection) Haulage
distance
Question (Practice by the course participant)
Compute the cost per hour of a tipper lorry purchased at UGX 40m. The truck was bought through a loan
scheme with 15% interest and has 5years useful life after which, it can be sold for UGX 10m. Assume the
operating cost to be 10% and the owner’s profit 5%. Use the four methods and compare the results.
MATERIALS
The cost of materials varies considerably depending upon the firm which supplies and the purchaser.
Factors determining cost of material (unit rate of materials)
Quantity to be purchased
Inflation
Annual turnover of the supplier

Law of demand and supply
Speed with which the purchaser settles the account
Wastages to be encountered e.g cutting waste, application waste, stock pile waste, residue
waste, transit waste and theft & vandalism.

37
Sources of information for the prices of resources
Press on radios, TVs by technical teams.

Site visits
Manufacturers
Institutions set up as the source of cost information centers e.g UBOS.
From sister companies and dealers
From sub contractors and suppliers Contacting
local people
PROFITS AND OVERHEADS
A profit is a return on business.
Factors considered before assessing the profits
Quantity commitment (amount of work to handle at a particular time

Future commitment
Placing in previous tendering
Possibility of future work from the same client/ owner
Assessment of the degree of competition
Terms of payment
Expected working conditions
Source of capital e.g if borrowing money from the financial institutions) Complexity of the
work
PRELIMINARY & GENERAL WORKS THAT NEED PRICING
Plant
Compound and hoarding
Watching, lighting and security
Water works supplies
Temporary road
Site offices
Removal of rubbish
e.t.c.

38
EXCAVATION AND EARTHWORKS

Earthworks refer to engineering works created through the moving of massive quantities of soil or
unconfined work.
Before pricing which unit rates for excavation works are needed, the estimator should visit the site to
ascertain what anticipated conditions will be at the time the work is to be carried out.
Examples of earthworks
Site stripping
Clearing and grabbing

Cut & fill site balancing
Rough and fine grading
Earth moving and stock pilings
Earth compaction
Field survey and layout
Building temporary roads
Soil stabilization
Park development
Site rehabilitation
Top soil placement
There are two methods of excavation that is the manual and mechanical method.
Factors considered when choosing the method of excavation
i. Volume of work to be done

ii. Availability of labour
iii. Time frame to complete excavation
iv. Nature of the material to be excavated
v. Depth of excavation
vi. Haulage distance
Factors that affect excavation rate
i. Weather conditions e.g rainy season

ii. Nature of the soil; clay, sandy/rocky
iii. Water content (effects when loading the machine)
iv. Bulking which is the increase in volume due to disturbances during excavation.
v. Cost of tip and haulage distance
vi. Method of excavation; manual/mechanical
39
vii. Required width and depth of excavation

viii. Operator’s skills
ix. Level of site organization and supervision
Use of mechanical plant

Factors considered in acquiring a plant are:
Availability of funds
Utilization (how much work is available to keep the plant working?)
Time scale of the project
Ways of acquiring of mechanical plant

Hiring; the advantage is that a plant can be hired for a minimum period required and the
disadvantage is being expensive if it’s to be hired for a long time.
Purchasing; the owner of the plant must have sufficient work for the plant to avoid idleness
leading to financial loss. This is through firm’s own contracts or through public hire business.
Leasing agreement
How to compute for the cost of using a plant per hour

Hiring; negotiable on how much to pay per day or week and dividing by the total working hours.
For purchased plant, a built up of hourly rate is done
Costs to consider when purchasing
Purchase rate
Interest on capital
Recovery of purchase price
Operating cost (operator, fuel)
Maintenance
Insurance
Taxes
Information required before purchase
Have knowledge of the life cycle of the plant

Hours that the plant will be utilized by annum
Output of plant
Maintenance and repair requirements
Examples on excavation and earthworks

40
One
To excavate a basement starting at ground level to reduced level to a maximum depth not exceeding 2m
using a 0.25m3excavator which load directly to lorries for disposal costs 24,000/= per hour. The excavator
outputs 9m3 per hour. Assuming a bank man is paid 1200/= per hour, compute the cost per cubic metre.
Solution
Total cost is 24000+1200 = 25200/=
Therefore, cost per cubic metre = 25200/9 = 2800/=
Two
A CAT 973 Crawler excavator of bucket capacity 2.5m3 and cycle time 2 minutes is to be used to excavate
a 48x36x4m basement and load into a 15m3 Volvo Euclid R32 tipper Lorries of speed 40km/hr and
55km/hr loaded and empty respectively. The travel distance from the basement to the dumping site is
2.7km and the time for maneuvering at both ends is 2minutes, tipping time is 2minutes and waiting time
is 1 minute. Job efficiency is 85% and bulking is 25%.
Assuming 5 days in a week and 8 working hours a day,
a) Estimate the excavator’s work out put in m3 per day.

b) The contract period in weeks.
c) Number of Lorries required to match the excavator.
Solution
𝑄𝑥𝐶𝐸𝑥60𝑥𝑇𝑥𝐹𝑥𝐸
a) Output of excavator = Cm
Where; Q = Capacity
CE = Bucket fill factor
T = Time period for which production is done.
F = Soil factor
E = Job efficiency
Cm = Cycle time
2.5𝑥1𝑥60𝑥1𝑥1𝑥0.85
Output of excavator = 2
= 63.75m / hr
∴ Output per day = 63.75x8 = 510mm / day
b) Volume of excavation 48x36x4 = 6912m3

41
Volume to be transported = 6912x1.25 = 8640m3
Number of weeks = 8640/510 = 17 days = 17/5 = 3.4weeks. Say 4 weeks.

15 2.7 2.7
c) Cycle time for lorries = 1+ 2 + 2 +2.5 x2+ 40 x60+ 55 x60= 24min
𝑄𝑥𝐶𝐸𝑥60𝑥𝑇𝑥𝐹𝑥𝐸 15𝑥1𝑥60𝑥1𝑥1𝑥0.85
Output of Lorry = Cm
= 24
= 31.9m / hr
Number of Lorries = (63.75/31.9) = 2 Lorries.
Three
Estimate the cost per CM of a 7m wide road sub-base supposed to be filled to a 600mm thickness in
layers of 150mm and compacted using a 10 tonnes roller costing 800,000 per day of 8 working hours. A
grader hired at 600,000 per day is to be used for spreading the marrum; the marrum shall be excavated
using a 2.5m3 excavator and it’s assumed to have just the original moisture content for maximum
compaction and will be loaded directly into lorries of 15m3 capacity for disposal at the site 3km away.
Travel speed for the lorry is 40km/hr loaded and 55km/hr empty.
The excavator is able to excavate and load in 2 minutes per every bucket. The maneuvering time at both
ends is 2minutes, waiting time is 1minute and tipping time is 2minutes efficiency of 85%. Bulking factor is
25%.
The excavator and lorry were purchased at 400m UGX and 120m UGX respectively and have useful lives
of 10 years.
The cost of capital is 15% and as a prospecting contractor, the other figures for maintenance, insurance,
taxes, profits and overheads are to be assumed. Use the method of depreciation of your choice to
determine the total cost of the sub-base per a km.
Solution
Volume of earth work in a km = 0.5x0.6x (7+7+1.2) x1000 = 4560m3
Adding 30% consolidation, Volume to be transported = 4560x1.30 = 5928m3. Say 6000m3
𝑄𝑥𝐶𝐸𝑥60𝑥𝑇𝑥𝐹𝑥𝐸 2.5𝑥1𝑥60𝑥1𝑥1𝑥0.85
Output of excavator= =
Cm 2
= 63.75m / hr
∴ Output per day = 63.75x8 = 510mm / day
Number of days required = 6000/510 = 12 days

15 3 3
Cycle time for Lorries = = 1+ 2 + 2 +2.5 x2+40 x60+55 x60= 24.8min
𝑄𝑥𝐶𝐸𝑥60𝑥𝑇𝑥𝐹𝑥𝐸 15𝑥1𝑥60𝑥1𝑥1𝑥0.85
Output of Lorry = Cm
= 24.8
= 30.85m / hr

42
Number of Lorries = (63.75/30.85) = 2.1. Say 3 Lorries.
Assuming that a grader can spread 510m3/day and the roller can compact 510m3/day. Required
equipments and labourers are;
No of equipment No of skilled labourers No of Unskilled labourers
Excavator 1 1 1
Lorry 3 3 3
Grader 1 1 1
Roller 1 1 1
Add one supervisor for both skilled and for unskilled and 2 watch men, 2 flag men plus one standby for
skilled and unskilled.
Total skilled = 1+3+1+1+1 = 7
Total Unskilled = 1+3+1+1+1+2+2 = 11
Assume 3000 for supervisor 2000 for skilled and 1500 for unskilled per hour
Total = (3000 + 2000x7 + 1500x11) x8 = 268,000/ per day
Equipment
Excavator
Initial capital 400m
Interest on capital = 15%
Assume all other rates (profit, overheads, running) = 20%
Using sinking fund method
(1+ i)n
R= P i
(1+ i)n −1
(1+ 0.15)10
R = 400 0.15= 79.7millions
(1+ 0.15)10 −1
Adding others 1.2x79.7 = 95.64millions

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Recoverable amount per day = 95,640,990/50x5 =382,354/= per day.
Lorry
Initial capital 120m
Interest on capital = 15%
Assume all other rates (profit, overheads, running) = 20%
Using sinking fund method
(1+ i)n
R=P i
(1+ i)n −1
(1+ 0.15)10
R =120 0.15= 23.91millions
(1+ 0.15) −1
Adding other 1.2x23.91 = 28.69millions
Recoverable amount per day for one Lorry= 28,692,000/50x5 =114,769/= per day
Recoverable amount for 3 Lorries = 114,768x3 = 344,304/= per day
Grader
Hire rate per day 600,000x1.2 = 720,000/= per day
Roller
Hire rate per day 800,000x1.2 = 960,000/= per day
Total cost is 268,000 +382,354 + 344,304 + 720,000 + 960,000 = 2,674,658/= per day
Cost per CM = 2,674,658/510 = 5,244/= per CM
Cost per km = 5,244x6000 =31,464,000/= per km.
LABOUR AND LABOUR CONSTANTS

Labour output is the most uncertain part of a unit area. It varies considerably depending on the operatives,
site organization, weather conditions and other factors outside the control of the contractor. Records of
labour outputs of each operative involved in construction have been kept for many years, taking into account
varying conditions and a comprehensive list of skilled and unskilled times has been prepared. These records
which give the average unit times for each operative is what is called labour constant.

44
Factors considered in the use of manual labour in excavation
• Government policy e.g labour base for rural road construction.

• Depth of excavation
• Availability of labourers
• Volume of excavation
• Urgency of work
• Haulage distance
The following are average labour constants for hand excavation under normal conditions and in ordinary
grounds like heavy soils or medium clay.
Description Unit Un skilled labour
Lifting and stacking turf SM 0.3
Exc. Veg. av.150mm SM 0.3
Surface exc.av.dp.150mm SM 0.45
Surface exc. to reduce level CM 2.4
Exc. Basement n.e 1.5m deep CM 2.9
Exc. Basement exceeding 1.5 n.e 3.0m deep CM 5.9
Exc. Basement exceeded 3m, n.e 4.5m deep CM 7.25
Exc.fdn trench exceeding 1.5m, n.e 3.0m deep CM 6.5
Exc.fdn exceeding 3m, n.e 4.5m deep CM 8.125
Exc.isolated stanchion fdn n.e 1.5m deep CM 5.0
Exc.isolated stanchion fdn exceeding 1.5m, n.e 3m deep CM 10.0
Wheeling exc. Mtrl by barrow per 100m CM 1.0
Spread & level exc mtrl in layers 150mm thick CM 1.3
Load exc mtrl into lorry as dug CM 2.0
For excavation in other materials than medium or heavy soils, adjust the above labour constants as
follows:

45
Loose sand …………………………………………………………………………………..x0.7
Stiff clay or gravel …………………………………………………………………………x1.50
Soft rock ……………………………………………………………………………………x3.00
Hard rock ……………………………………………………………………………………x8.00
Below are the increases in bulk of various types of soils after excavation
Gravel ……………………………………………..% increase ………………………………..10
Sand ……………………………………………………………………………………………12.5
Ordinary earth……………………………………………………………………………………25
Clay…………………………………………………………………………………………….33.3
Chalk …………………………………………………………………………………………..33.3
Rock …………………………………………………………………………………………….50
Example 1
Lifting and stacking turf (SM)
0.30 unskilled hours @500/……………………………………………………………………150/ Cost per
SM……………………………………………………………………………………150/
Example 2
Surface excavation av.150mm deep to reduce level (SM)
0.45 unskilled hours @ 500……………………………………………………………………225/
Cost per SM of surface excavation…………………………………………………………….225/
Example 3
Excavate trench to receive fdn exc. 3m, n.e 4.5m deep (CM)
8.1256 unskilled labour hour @500………………………………………………………4062.5/
Cost per CM…………………….………………………………………………………..4062.5/
The labour constant above has been based on the following:
Two labourers excavating and taking 1.625 gang hours per CM to excavate and stage 1.5m
One labourer at every other 1.5m stage taking 1.625 hours per CM to excavate and stage 1.5m One
labourer clearing back at top of excavation taking 1.625hours per CM

46
Summary
Excavate and stage 4.5 to 3.0 =2*1.625…………………………………………………….3.250
Stage 3 to 1.5m………………………………………………………………………………1.625
Stage 1.5 to ground level……………………………………………………………………..1.625
Clearing back at top………………………………………………………………………......1.625
Total …………………………………………………………………………………………8.125
8.125 hour per CM = 8.125 @ 500…………………………………………………………4062.5/
Example 4
Calculate the unit rate of excavation of over site 150mm and deposit at a distance 100m from the
excavation.
A SM of surface excavation takes unskilled labour 0.45 hours
Say an hour labour rate is 500/=
Cost of excavation for 0.45 @ 500 …………………………………………………………225/=
Deposit 100m away by barrow takes 1 hour @ 500*0.15……………………………………75/=
300/=
The cost of excavating surface to average depth of 150mm and depositing 100m is 300/=.
This excludes the contractor’s profits and overheads.
Example 5
Calculate the unit rate of excavation of over site 250mm and deposit at a distance 200m from the
excavation.
Since the depth and haulage distance has changed, we can use proportion.
Cost of excavation 250mm is 0.25/0.15*225….……………………………………………..375/=
Deposit 200m away by barrow takes 2 hour @ 500*0.25……………………………………250/=
625/=
The cost of excavating surface to average depth of 250mm and depositing 200m is 625/=.
This excludes the contractor’s profits and overheads.

47
CHAPTER FIVE
CONCRETE WORKS
Factors that affect the cost of concrete

There are three main initial factors to be considered in the costs of concrete:
• Method of mixing
• Materials being used, their specifications and grade of concrete
• Site transportation, placing and compaction
Other factors are:

• Type of mixer to be used
• Whether cement is supplied in bag or in bulk
• Workmanship and finishing expected
• Position of mixing in relation to the areas and quantities of concrete to be placed
• Whether in-situ mixed concrete or ready mixed concrete is to be supplied
• Site organization
• Work continuous or intermittent
CALCULATIONS FOR COST OF CONCRETE

Correction factors for concrete and for mortar
For concrete
The voids in concrete take up 40%
(V +∂v )0.6 = V
V +∂v =1.667V
∂v = 0.667V
E.g withV = 7,
TotalVolume = (7 + 0.667x7)0.6 = 7.0014 ≈ 7CM
For mortar
The voids in mortar take up 25%

48
(V +∂v )0.75 = V
V +∂v =1.333V
∂v = 0.333V
Question One
Concrete of mix grade 20 (1:2:4).
Calculate using volume batching, the unit rate of concrete and prepare the materials delivery list given
the following information considering a slab of 7m by 15m of 150mm thick:
Cement…………………………………………..@ 36,000/ per 50kg bag
Transport for cement………………………………500/ per bag
Unloading cement………………………………….50/ per bag
Sand ……………………………………………….15,000/ per CM delivered
Aggregate………………………………………….40,000/ per ton delivered
Densities
Cement……………………………………………..1.3ton/CM to 1.4 (1300kg/m3 to 1400kg/m3)
Moist sand………………………………………….1.3
Dry sand…………………………………………….1.5 Aggregate
…………………………………………..1.6
Solution
1400kg of cement are contained in 1CM
1kg…………………………….. …CM/1400…………………………………..(i)
50kg of cement are contained in 1bag
1kg…………………………………bag/50…………………………………….(ii)
From (ii)/(i)
1CM of cement contains 1400/50 = 28bags.
1CM of cement……………………………28bags @ 36,0000……………………1,008,000/
Transport for 28 bags @ 500……………………………………………………….14,000/
Unloading of 28 bags @ 50…………………………………………………………1,400/

49
2CM of sand delivered @ 15,000………...................................................................30,000/
4CM of aggregates delivered …..4x1.6x40,000……………………………………256,000/
Total 1………………………………..1,309,400/
Cost of 1CM of dry concrete with ………(1,309,400 + 0.667x1,309,400)/7……….311,824/
Voids catered for
Allow 5% waste……………………………………………………………………..15,591/
Concrete mixer 0.5hrs @ 6250……………………………………………………….3125/
Unskilled labour 6 @ 1000…………………………………………………………...6000/
Total 2…………………………………333,422/
Add 25% profits and overheads………………………………………………………..83356/
Total 3…………………………………..416778/
Cost per CM of concrete of grade 20 is ……………….416778/
Cost per SM of floor slab is……0.15x416778…………62517/
Therefore the unit rate for the floor slab is 62,517/ per square metre.
Preparation of materials delivery list
There are 28 bags of cement in 1CM and this was used to produce 7CM.
After mixing with water, volume of concrete = 7x0.6 =4.2CM due to 40% shrinkage.
Therefore, 1CM of concrete requires 28/4.2 = 6.7 bags. Say 7 bags of cement.
4.2CM of concrete were given by 2CM of sand
Therefore, 1CM of concrete requires 2/4.2 = 0.48CM of sand
4.2CM of concrete were given by 4CM of aggregates
Therefore, 1CM of concrete requires 4/4.2 = 0.95CM of aggregates….0.95x1.6 = 1.52tons
Volume of the slab = 0.15x7x15 = 15.75CM
Materials required for the 15.75CM of concrete
Cement = 7x15.75………………110.25 bags. Say 110 bags
Sand = 0.48x15.75………….7.56 CM. Say 8CM.
Aggregates = 1.52x15.75………23.94 tons. Say 24 tons.

50
Item Description Unit Qty Rate Amount
1 OPC Bag 110 36000 3,960,000
2 Sand CM 8 15000 120,000
3 Aggregates Ton 24 40000 960.000
Total 5,040,000
Question Two
A 150mm thick reinforced concrete slab is to be cast in-situ in concrete grade 30 (1:1.5:3).
a) Compute the unit rate for concrete ignoring the cost of reinforcement and formwork.
b) Produce a material delivery list if the slab required 100m3of concrete.
Data
OPC delivered and offloaded per bag of 50kg cost 29,000/
1 ton of lake sand delivered cost 15,000/
1 ton of 20mm aggregates from Namanve cost 40,000/
Concrete mixer of capacity 2CM per hour is hired at 40,000/ per day of 8 working hours
Porker vibrator is hired at the rate of 24,000/ per day of 8 working hours
Allow 40% of voids in concrete
Unskilled labour constant for concrete is 6hours
Skilled labour constant is 0.3hours
Unskilled labour rate is 625/
Skilled labour rate for concrete is 1500/
Allow 20% for profits and overheads
Solution
(a) Unit rate of concrete
Volume batching in the ratio 1:1.5:3
1CM of cement……………………………28bags @ 29,000………………………812,000/
1.5CM of sand each ton @ 15,000………...........1.5x1.3x15000 delivered................29250/

51
3CM of aggregates delivered …..3x1.6x40,000……………………………………...192,000/
Total 1………………………………..1,033,250/
Cost of 1CM of dry cement with ………(1,033,250 + 0.667x1,033.250)/5.5………..313,169/ Voids
catered for
Allow 5% waste…………………………………………………………………………156581/
Concrete mixer (40000/8)x0.5hours…………………………………………………….2500/
Porker vibrator (24000/8)x0.5hours……………………………………………………..1500/
Unskilled labour 6 @ 625…………………………………………………………..........3750/
Skilled labour 0.3x1500/………………………………………………………………….450/
Total 2…………………………………….337,027/
Add 20% profits and overheads……………………………………………………………67405/
Total 3……………………………………404,432/
Cost per CM of concrete of grade 30 is ……………….404432/
Cost per SM of floor slab is……0.15x404432…………60665/
Therefore the unit rate for the floor slab is 60665/ per square metre.
(b)Preparation of materials delivery list
There are 28 bags of cement in 1CM and this was used to produce 5.5CM.
After mixing with water, volume of concrete = 5.5x0.6 =3.3CM due to 40% shrinkage.
Therefore, 1CM of concrete requires 28/3.3 = 8.5 bags.
3.3CM of concrete were given by 1.5CM of sand
Therefore, 1CM of cement requires 1.5/3.3 = 0.45CM of sand ….0.45x1.3 = 0.59tons
3.3CM of concrete were given by 3CM of aggregates
Therefore, 1CM of cement requires 3/3.3 = 0.9CM of aggregates….0.9x1.6 = 1.45tons
Materials required for the 100CM of concrete
Cement = 8.5x100………………850 bags.
Sand = 0.59x100……………..59 tons.
Aggregates = 1.45x100…………145 tons.

52
1 OPC Bag 850 29000 24,650,000
2 Lake Sand Ton 59 15000 885,000
3 20mm machine crushed aggregates Ton 145 40000 5,800,000
Total 31,335,000
Assignment 2
A concrete floor slab 4.8mx4.2m and 150mm thick is to be cast over a plinth wall building. The mix
ratio is 1:2:4/20mm aggregates. Develop a unit rate for mixing concrete using the following available
information.
• Due to persistent wind flow, shrinkage of concrete is considered at 40% and waste of 5%
• Mixer 14/10 concrete mixer at UGX 150,000 per day with an output of 3 minutes/m produces
5.75m3/hr
• Vibrating poker is UGX 60,000 per day
• Cement costs UGX 32,000 per 50kg bag
• 7 tonne tipper truck of sand is UGX 320,000
• 7 tonne tipper truck of stone aggregates is UGX 450,000
• Mixer operator gets UGX 35,000 per day
• Helper gets UGX 25,000 per day
• Allow 25% profits and overheads
• Labour constants for concrete mixing per m3:
Unskilled 6hrs
Skilled 0.3hrs
FORM WORK
Before pricing the unit rates for form work, the estimator will consider the following items:
• Whether metal or timber form work

• The design of the form work to be used
• The estimated number of times the form work can be used.
• The labour involved in making, fixing and stripping.
Timber form work

The following is a typical method of building up:
Cost of material in making, plus cost of labour in making, divide by the estimated number of uses.

53
Add the following;
• Labour for fixing and stripping

• Treatment of shutter face with soap oil, shutter paint or any other treatment after stripping
Repair and cleaning after each use
• Beam hungers, wall ties, and the like, bearing in mind that bolts can be use several times
• Column cramps, steel prop and similar items
• Cost of ply wood sheets including unloading and waste of 7% divided by the number of uses
CALCULATIONS ON FORM WORK
Question One
Compute the cost per square metre of a 225x225x3 column box to be made from 250x25x4.2m
soft boards and braced with 50x50 timbers. The cost of timber per CM is 500,000/ delivered and
offloaded. The formwork shall be supported using eucarlyptus poles costing 2000/ delivered to
site. One carpenter and one assistant are expected to fabricate two column boxes ready for
concrete per day. Solution
Braces
Using a spacing of 500mm
L = 100+275+100 = 475mm = 0.475m
Volume = 0.475x0.05x0.05 = 1.1875x10-3CM
Cost of braces = 1.1875x10-3x500000x7x4 = 16625/=
Boards
3x0.025x0.275x500000x4 = 37500/=
54
Cost of eucalyptus poles = 4x2000 = 8000/

Total cost = 16625 + 37500 + 8000 = 62125/
Add 10% wastage = 6212.5/
Total cost of one column boxes = 68338/
Cost of two columns boxes =68338x2 = 136676/
Adding labour = (15000+10000) =25,000/

Total cost of two columns boxes = 161676/=
Area of column box 0.25x3x4 = 3SM x 2 for 2 column boxes
Cost per SM = 161676/3 = 53892/ per SM for two columns
For one column box = 53892/2 = 26946/= per SM of one column box
The course participant can add cost for treatment and then add 20% profits and over heads to get
the actual cost per SM of a column box.
Question Two
What will be the cost of reinforced concrete column of 225x225x3 if it requires 16mm bars of 6No. per
column and 8mm stirrups at 200mm centres are to be used. Reinforcement costs 2,000,000/ per ton
delivered to site. Use example two on calculations for cost of concrete to get the cost per CM of plain
concrete (404432/=)
Data
Wastage =5%
Tie wires and spacers =2%
Cutting and bending rate =15hrs/ton
Fixing rate = 20hrs/ton
Bar bending machinery = within on-site cost
Site transportation = with in on-site cost
Labour for steel fixer = 3000/hr
Solution
Compute the volume of the column = 0.225x0.225x3 = 0.1485CM
Using the unit cost of concrete (404432/), compute the cost of concrete required for the column as
0.1485x404432 = 60,058/=
55
Reinforcement
Purchasing 2,000,000/ per ton
Wastage of 5% of purchase 100,000/
Add 2% of purchase for spacers and binding wire 40,000/
Labour (15+20)x 3000 105,000/ per ton
Total 2,245,000/per ton
Starter bar
3m
0.8m
Length of links = 225 -50 = 175x4 = 700 + 100(bending) = 800mm.
Assume a spacing of 200 as in question
No of links = 3000/200 = 15 + 1 = 16
Total length of stirrups = 16x800 = 12,800mm = 12.8m of 8mm bar.
Length of 16mm bars = 3+0.8 = 3.8x6 = 22.8m
Computing the weight per linear metre (∏r2ρ)
For 8mm bar; using density of steel as 7800kg/m3
2
4
∏ x7800 = 0.39kg / m
1000
For 16mm bar
2
8
∏ x7800 =1.57kg / m
1000
Computing the weight of 8mm and 16mm bars

For 8mm bars

56
12.8x0.39 = 4.992kg
For 16mm bars
22.8 x 1.57 = 35.796
Total weight = 4.992 + 35.796 = 40.788kg = 0.041tonnes.
Cost of reinforcement = 2,245,000x0.041 = 92,045/=
Therefore, total cost of a reinforced column = (60058+92045) = 152,103/=
N.B: Add 20% Profits and Overheads on the 92045/=

57
CHAPTER SIX
BRICK/BLOCK WORK
Factors that affect the costs of brick/block work
• Wall thickness
• Workmanship or finishing expected
• Height of workplace
• Whether activity is continuous or intermittent
• Specification of building unit
• Skills of masons
• Level of supervision and site organization
In order for the estimator to price the unit rate for brick or block, it is necessary for him to know the
following:
• How to build up the price per cubic metre for the mortar to be used
• The number of bricks or block in a SM
• The percentage to be added for waste
• Amount f skilled and unskilled hours required for each unit operation
CALCULATIONS FOR UNIT RATE OF A CONCRETE BLOCK/BRICK WALL
Question One
A 225mm thick wall is to be constructed out of 350x225x150mm concrete blocks and bonded using
20mm thick mortar joints of mix 1:4. Compute the unit rate for concrete block wall and produce a
material delivery list for a plinth wall shown below. Assume all walls as 230mm.

58
100
GROUND PLAN Section thru the fdn

Solution
Determining the cost of 1CM mortar

1CM of cement 28 @ 29,000……………………….812,000/
4CM of sand 1.3x4x15000……………………….78,000
Total 890,000/=
Cost of 1CM of dry mortar with (890,000x1.33)/5 =236740/=
with voids catered for
Add 5% waste = 11837/=
Concrete mixer (40000/8)x0.5hrs = 2500/=
Unskilled labour 625x6 = 3750/=
Total 254,827/=
Therefore the unit cost of mortar is approximately 300,000/=

Coordinated block = 370x225x170
Area of one block =0.37x0.17 = 0.0629SM
No of blocks in 1SM = 1/0.0629 = 16blocks.
Volume of mortar = 0.225x1x1 – (16x0.35x0.15x0.225) = 0.04CM
225
Mortar 0.04 @ 300,000………………………………......... 12,000/
16 blocks delivered @ 2000………………………………. 32,000/

59
Add 5% waste for cutting of blocks………………………. 1600/
Unskilled hours 1.2 @ 625………………………………. 750/
Skilled hour 0.6 @ 1500……………………………… 900/
Total 47250/=
Add 20% profits and overheads…………………………… 9450/
Total 56700/=
Therefore the unit cost of a 225mm thick block wall = 56700x0.225 = 12,758/=
Adding water to mortar of 1:4 with the voids of 25%, the wset volume becomes 5x0.75 = 3.75CM
Therefore, 1CM of mortar requires 28/3.75 = 7.5 bags.
3.75CM of mortar were given by 4CM of sand
Therefore, 1CM of mortar requires 4/3.75 = 1.07CM of sand ….1.07x1.3 = 1.391tons
Total wall length is 57.93m and total wall height is 0.57m, therefore area = 33SM and the volume is
7.61CM.
1SM of a 225mm wall contains 0.04CM of mortar
1SM of a 230mm wall contains (0.04x230)/225 = 0.041CM of mortar
1SM of a 230mm wall contains 0.041CM of mortar
33SM of a 230mm wall contains 0.041x33 = 1.353CM of mortar
1SM of a 225mm wall required 16blocks
1SM of a 230mm wall requires (16x230)/225 = 16.4blocks
33SM of wall requires 16.4x33 = 541.2blocks say 542 blocks
Materials required
Cement = 7.5x1.353………………10.1 bags. Say 11bags.
Sand = 1.391x1.353……………..1.9 tons. Say 2 tons.

1 OPC Bag 11 29000 319,000
2 Plaster Sand Ton 2 15000 30,000
3 Blocks No 542 2000 1,084,000
Total 1,433,000

60
Question Two (For the course participant to practice)

A 150mm thick wall is to be constructed out of 230x150x100mm common bricks and bonded using
20mm thick mortar joints of mix 1:4. Compute the unit rate for common brick wall and produce a
material delivery list for a plinth wall shown below. Assume all walls are 230mm thick.
690
GROUND PLAN Section thru the fdn

61
CHAPTER SEVEN
7.0 CARPENTRY AND JOINERY
Timber for carpentry and joinery works can be purchased from the timber merchants in a sawn state,
planed or planed and moulded. The basic selling unit is the cubic metre but joinery rails, e.t.c are
normally quoted for per linear metre. If sawn sections and lengths are required which correspond
exactly to the members that are supplied by the manufacturers, the price will be cheaper than if the
builder requires specific length and sections which requires to be reduced to the required sizes on
site. The emphasis in modern construction is to fabricate the components in a specialist’s sub-
contractors workshop wherever possible and reduce the site labour to a minimum. Examples of such
items are roof trusses, doors and frames, windows, staircases, cupboard units e.t.c.
Waste
The cutting and waste factor on insitu carpentry and joinery can be generally at about 10% but for
certain members in some situations, it may be higher.
Factors that are considered in estimating for any carpentry and joinery work
The size of sections required

Labour involved
Type of item being made e.g roof trusses, door and windows
Purpose of structure
CALCULATIONS FOR UNIT RATE FOR ROOFING
Example One
Calculate the unit rate of a piece of 150mm x 50mm timber if each cubic metre of timber costs UGX
500,000.
Solution
Unit rate = 0.15 x 0.05 x 500,000 = UGX 3750.
Example Two (Roofing in Tiles)

Compute the unit rate for roofing in Kiwa tiles of size 400 x 225 with side laps of 25mm and end lap of
75mm if one tile costs 1600Ushs delivered. The tiles are hooked on 50x38 battens converted from
150x50x4200 pine timber. Each piece of 150x50x4200 costs 24,000Ushs delivered to site. The battens
are to be fixed using 76mm nails each costing 30Ushs. What is required for a roof area of 300m2?
Galvanized iron sheets costs 5000
62
Solutions
Tiles
Exposed area of tile ……………………………………..(0.4 -0.075)(0.225 – 0.025) = 0.0625m2
Number of tiles in a SM ……………………………………………………..1/0.0625 = 15.38
Add 2.5% waste………………………………………………………………………. = 0.38
Total number of tiles …………………………………………………………….…………16
16 tiles @ 1600 delivered ……………………………………………………………….25,600/
Unskilled labour for offloading 0.3hrs @ 1000 ……………………………………………300/
Total 1 25900/
Battens
Consider spacing of 325mm
Number (length) of battens in a SM 1/0.325 ……………………………………………….3.08
If 150x50x4200 costs 24,000Ushs, then 38x50x3.08 costs 4,458/=
0.05 x 0.038 x 500,000 x 3.08…………………………………………………………….. 2926/
Allow 10% cutting waste …………………………………………………………………..293/
Total 2 3219/
Nails
Consider a spacing of 600mm
Number of nails 3.08/0.6 ……………………………………………………………………..5
5*30 …………………………………………………………………………………………150/
G32 iron sheet @ 6000 …………………………………………………………………….6000/
Unskilled labour 0.3 @ 1000 ………………………………………………………………..300/
Skilled labour 0.6 @ 2500 …………………………………………………………………1500/
Total 3 7950/
Total cost 37069/

Allow 20% profits and overheads……………………………………………………………7414/
Final cost 44,483/

63
The cost of roofing 1 SM of a roof in mangalore roofing tiles is 44,484/
The cost of roofing 300m2 44,483 x 300 = 13,344,900/=
Notes: produce a materials list if required
Example Three (Roofing in Corrugated Iron Sheets)

Compute the unit rate for roofing in corrugated iron sheets of size 3000 x 900 with side laps of 114mm
(in an iron sheet each corrugation measures 76mm = 76x1.5 = 114mm) and end lap of 150mm. The
iron sheets are fixed to timber purlins with nails and washers. The roofing sheet costs 15000Ushs per
SM, roofing nails costs 5000Ushs per a kilogram having 50 nails. There are 10 nails in a SM of roof
surface and the washers cost 50Ushs each.
Solution
Exposed area is (3 – 0.15)(0.9 – 0.114) ……………………2.24SM
Cost of 2.24SM @ 15000 …………………………………………………………………33,600/
Add cutting waste 5% ……………………………………………………………………….1680/
35,280/
Roofing nails 2.24 x 10 x 5000/50 …………………………………………………………..2240/
Add 5% waste………………………………………………………………………………….112/
37,632/
Washers 2.24 x 10 x 50 ………………………………………………………………………1120/
Add 5% waste ………………………………………………………………………………….56/
38,808/
Unskilled labour 0.3 @ 1000 ………………………………………………………………….300/
Skilled labour 0.3 @ 2500 …………………………………………………………………….750/
39,858/
Add 20% profits and overheads 7,972/
47,830/
The unit rate for roofing in iron sheet of gauge 28 pre-painted is 47,803/

64
CHAPTER EIGHT
8.0 FINISHES
8.1 Plaster work and other floor, wall and ceiling finishes and beds
Lime plaster has backing and rendering of course stuff and a finishing or setting coat of fine stuff.
Before the price of lime plastering can be analyzed, the basic cost of course, stuff and fine stuff must
be ascertained.
The labour in mixing plastering materials is covered by the time of the attendant labourers in the
plastering gang, as two labourers can supply 3 plasterers with all the materials they require and do all
the mixing. Generally, the mixing is carried out by mixing machines.
CALCULATIONS FOR UNIT RATE FOR FINISHES
Example One
Courses stuff (1:2:9 mix for render backing for lime plaster)
Consider 1Cm of cement of 28bags @ 28,000 ………………………………………..784,000/
2CM of Hydrated lime including unloading @ 450,000 ………………………………900,000/
Plaster sand 9tons @ 15000 ……………………………………………………………135,000/
1,819,000/
Allow for shrinkage, consolidation and waste of 50% …………………………………909,500/
2,728,500/
The cost of 1CM of plaster 2728500/12 …………………………227,375/
The labour for mixing is included in the plastering gang, profits and overheads can be added to the net
price.
Example Two
Calculate the unit rate for plaster in cement-lime-sand mix of 1:2:9 to a thickness of 20mm. First coat
be 12mm thick, second coat be 6mm thick and finishing coat be 2mm (this is normally lime-cement
mix).
Cement-lime-sand mix of 1:2:9 costs 227,375/
First cost 12mm…………0.012 x 227375…………………………………………………..2,729/

65
Compression of 50%................................................................................................................1,365/
Second coat 6mm……...0.06 x 227375……………………………………………………..1,364/
Compression of 20%................................................................................................................273/
5,371/
Finishing coat cement - lime (1:10) of 2mm
28 bags of cement ………………………………………………………………………784,000/
56 bags of lime (25kg/bag)……………10 x 2 x 28000…………………………………560,000/
1,344,000/
Allow for voids and waste of 10% 134,400/
1,478,400/
Cost per CM 1,478,400/11……………………………………………………………134,400/
Therefore cost of finishing coat 0.002 x 134,400…………………………………………….269/
Unskilled labour 0.75 x 2500 ………………………………………………………………..1875/
Skilled labour 1.5 @ 1000 …………………………………………………………………...1500/
3,375/
Total is 5731 + 269 + 3375 9,375/
Allow 20% profits and overheads 1,857
11,250/
The cost of plastering a SM of wall is 11,250/
8.2 Floor Screed
Specifications: 40mm thick mix of 1:4 cement – sand
0.04CM @ 300,000………………………………………………………………………12,000/
Waste of 10%.......................................................................................................................1,200/
Cement slurry of 0.5mm thick @ 784,000…………………………………………………392/
Skilled labour 1.5 @ 2500………………………………………………………………….3750/
Unskilled labour 1.5 @ 1000……………………………………………………………….1500/
18,842/
66
Add 20% profits and overheads …………………………………………………………...3768/
22,610/
The cost of screeding 40mm thick concrete in cement-sand mix of 1:4 is 22,610/
ASSIGNMENET 3
Build up a unit rate for mortar per cubic metre in a standard 150mm thick concrete blockwork to BS
6098 in cement-sand mortar (1:3) given the following information;
• Density : cement = 1400kg/m3

Sand = 1500kg/m3
Aggregates =1600kg/m3
• Cement is UGX 30,000 per bag
• Unloading cement is UGX 500 per bag
• Sand is UGX 80,000 per tonne.
• Aggregates are UGX 250,000 per tonne.
• Labour for hand mixing per cubic meter is 5 hours at UGX 5,000 per hour.
• Labour for transporting and placing per Cubic meter is 2.5 hours at UGX 10,000 per hour.
• Shrinkage is 25%
• Wastage is 5 %
• Profits and overheads is 25%
• Contingency 5%
• All materials are as per delivery to site

67
CHAPTER NINE
9.0 PROCUREMENT
Definition
Procurement is the acquisition through purchase, rental, lease, hire way or any other legal means of
works, services, and supplies.
Aims and Objectives of procurement

A construction project will normally require technical and managerial staff, materials, plant and
manpower. If the client cannot have an in-house team and resources, then these items have to be
procured (or bought from elsewhere).
The main objective of procurement is to ensure that the resources needed for the project are
acquired in the most efficient and effective way, with emphasis on time, cost and quality. The main
resources to be procured are summarized below:
Procurement Methods
There are two categories of construction resources that need to be procured in any project, namely:
1. Technical and managerial expertise
2. Man power, plant & equipment and material
These resources can be procured in several different ways but the main methods include:
• Standard approach
• Early selection approach
• Design and construct approach
• Divided contract approach
• Direct labour approach
A. Standard approach
In the standard approach, the client procures the resources on two occasions namely; by appointing
consultants and then later contractors.
The role of the main contractor is to implement all the construction work.
68
the client on the
reclamation of the
consultant)
The consultants have to prepare complete work drawings and specifications before calling for tenders.
The standard approach is one of the most commonly used procurement approach. The standard
approach is however known to delay initial project implementation time.
B. Early selection approach

In the early selection approach, site operations are started earlier than normally possible. This is
achieved by overlapping the designing and construction stages.
Since drawings and specifications are not yet ready by the time the main contractor is appointed, it is
difficult to obtain a fixed rate for the works. This can increase the risk of disagreement between the
client and the main contractor.
The early selection approach is suitable for projects consisting of a series of similar sub-projects.
C. Design and construct approach

This approach is also sometimes known as a ‘package deal approach’ or ‘turnkey project’. Here the
contractor is responsible for both design and construction. Better coordination can sometimes be
achieved.
The approach is difficult to combine with competitive tendering procedure. The client has to rely
heavily on the integrity and competence of the contractor.

69
D. Divide contract approach

In the divide contract approach, a separate contractor is appointed for the part of work (e.g.
earthworks) so that site operations can be started earlier than would otherwise be possible.
The number of contracts may be increased and procurement will then be phased between the several
different contractors.
Appointment of main
contractor
Appointment • Earthworks
of consultant • framework
• Mechanical .work
• electrical .work
The disadvantage of divide contract approach is that the project manager will face greater problems
of coordinatio0n than with standard approach since responsibility on the construction site will be
divided between several contractors.
E. Direct labour approach

Direct labour is often used for smaller projects which are technically simple. The approach is normally
unsuitable for larger projects as construction capacity is li8mited by lack of plant and skilled staff.
Appointing of consultants
For technical expertise, it is often necessary to appoint consultants such as:
• Architects
• Engineers
• Quantity surveyor
Consultants should be asked to provide the following information to enable proper selection is made.
• Capacity of the firm
70
• Earlier experience in similar projects

• Proposed methods to be used for coordination and control
• Proposed project organization (including names and qualifications of key staff)
• Proposed activity plan
• Fees structure
ce
A formal contract should be signed between the client and the consultant. It can be based on one of
the standard terms of agreement prepared by either:
o IGRA - International General Rules of Agreement between client and consulting Engineer (1976)
o FIDIC - International Federation of Consulting Engineers
Payments to consultant are based on scale of fees determined as a percentage of the final
construction cost. The actual percentage varies with the service provided and the type of the project.
Appointing contractors
The recommended procedure for appointment of contractors is by competitive tendering. Tendering
itself is a process which involves several stages, namely;
• Selection of tenderers
• Invitation of tender
• Preparation of tender documents
• Tendering
• Evaluation of tenders
• Award of contract
• Notification to tenderers
Competitive tendering is governed by strict rules. The aim is to guarantee fair competitive and
unbiased tender evaluation. Tenders for government projects are usually submitted to a tender board
ot its equivalent.

71
Contract documents should normally include the

following: • Agreement between the client and
contractor
• Tender
• Standard conditions of contract
• Special conditions of contract
• Bill of quantities
• Schedule of prices
• Drawings and specifications
PROCUREMENT PROCESS
Procurement cycle
This encompasses a variety of tasks and responsibilities which begin with the determination of the
need of the products or services.
The cycle embraces several procurement and logical operations and is a key to better understanding
of the various inter-related activities in the procurement process.
Steps that take place in the procurement cycle
Recognition of the demand or need which is done by the procurement departments at different
levels of management
The detailed requirements are identified and described by reaching the local people who use the
services.
The budget is prepared and confirmed by the contracts committee.
The specifications and references or scope of works are developed by the committee.
The methods of procurement are decided on by the committee so as to favor every one and not to
incur looses.
The bid documents are prepared by the procurement department. Examples of bid documents
include: BoQs, Specifications, Drawings, Form of agreement e.t.c.
The contracts committee then announces in the press asking willing firms to pay a non-refundable
bidding fee. Upon payments, bidders obtain documents which the fill and return back to the
contracts committee on the stipulated time and date.
The documents are opened by the contracts committee in presence of the firms’ representatives.
This exercise involves checking all the bid documents handed in by each bidder and checking the
arithmetical error.
Evaluation of the bids then takes place and this is in two parts; the preliminary and technical
evaluation and financial evaluation.
Each bid is attributed to a preliminary evaluation to determine the responsiveness as per the table
below before they are considered for technical evaluation.

72
Bi d Nam Contac Physica Genera Valid Income VAT Certificate Power Remark
No e of t l l tradin tax registratio of of s
bidde addres address receipt g licens clearanc n certificate registratio attorne
r s origina e e n y
l
Each bidder must fulfill all the above requirements in the table before passing preliminary
evaluation.
Failure to have any of the requirements, the bidder is can not be considered for technical evaluation.
Any firm that forges any of the documents or shares receipts with another firm is disqualified
automatically.
Technical evaluation is carried out on firms that pass the preliminary evaluation and still bidders
have to present enough requirements in order to qualify for selection as a successful bidder. In this
part, marks are awarded and any bidder with marks below 50% does not qualify for selection.
Below is a sample of technical evaluation form for pre-qualification

73
KIRA TOWN COUNCIL TECHNICAL EVALUATION COMMITTEE Technical

Evaluation Pre-Qualification Form Name of
Bidder:……………………………………………………… Item: Deep Borehole Drilling
Criteria Weight Possible total Rating Total score Comments
score
Organization
Company experience 5 20
Personal 5 20
Gender balance 2 8
Local experience 3 12
Subtotal 60
Equipment
1. Rig 5 20
2. Test pumping equipment 4 16
3. Support transport 4 16
Subtotal 52
Personnel suitability
1. Contract manager 4 16
2. Field manager 5 20
3. Driller 4 16
Subtotal 52
Local establishment
Local company staffs 5 20
Subtotal 20
Finance
Drilling permit 5 20
Power of attorney 3 12
Finance security 5 20
Subtotal 52
TOTAL 236
% SCORE
Rating: Excellent – 4; Good – 3; Fair – 2; Acceptable – 1; Poor – 0
Evaluator……………………………….Date………………………….
For the organization, a company is supposed to have completion certificates in order to get marks for
experience, academic documents in order to get marks for personnel, women and men in order to get
marks for gender.
For equipment, a company is expected to either be owning or hiring but for hiring, a hiring agreement
is required.

74
For personnel suitability, academic documents are considered basing on the information given by the
bidder.
The company is supposed to have some good amount of money on the account and this can be
verified by presenting a bank statement.
Upon fulfilling all the above requirements and obtaining 50% and above, a firm has passed the
technical evaluation and is included on the list of firms that will be invited to tender for different
works under selective tendering.
The successful firms are invited to tender whenever work arises and they are required to submit in
their rates for executing the works plus the form of agreement.
Evaluation is carried out by the contracts committee and always the lowest bidder takes it
all. The winner then signs an agreement with the owner and this forms a contract between
them.
A Sample of Pre-Qualification Notice Sent to Contractors
Check out for the draft on next page

75
DEPARTMENT OF CIVIL AND BUILDING ENGINEERING – KYAMBOGO

UNIVERSITY
INVITATION FOR PRE-QUALIFICATION FOR PROVISION OF INTERNET SERVICCES
The department of Civil and Building Engineering has received funds from the ministry of ICT for the
improvement of the academic standards in the department.
In accordance with the above, the office of the head of department invites firms to submit bids for
prequalification for the provision of internet services.
Interested forms are expected to meet the following minimum criteria.
• Be registered and practicing members.
• Have no conflict of interest in provision of services to the office of the head of department.
• Have fulfilled obligations to pay taxes, social security contributions and other statutory/
regulatory responsibilities
• Are not subject to suspension by the civil and building department, Public Procurement and
Disposal of Public Assets Authority(PPDA) and other regulatory/ government bodies
• Have a valid trading license
• Are not subject to legal proceedings in respect of bankruptcy, or questionable business
dealings
The firms are expected to provide the following with their proposals
• A copy of trading license or equivalent
• A copy or certificate of registration or equivalent
• A copy of income tax clearance certificate or equivalent (where applicable)
• A copy of evidence of VAT registration
• A signed statement that the bidder does not have a conflict of interest in providing such services to
the department
• Evidence of certification of members/ partners by regulatory organization
• Any other relevant documents or statements
More details are in the tender documents obtainable from the head of department’s office upon
payment of a non refundable fee of 150,000/=.
The firms may indicate the types and volume/size of services carried out in the last three years,
number and qualifications of staff employed both technical and support, location and braches, and
other aspects deemed relevant.
The firms are required to submit their proposals not later than 30th October 2011 at 5:00 pm; to:
The Secretary, academics committee, Office of the Head of Department Civil, Room 5.0A, Civil
Building, Kyambogo University P.O Box 1, Kampala (U)
Note: Late submissions will not be accepted
76
Mrs. Ann. Babirye For: Head of Department Civil
Bibliography
Ferry. D.J and Brandon, P.S., 1980, Cost Planning, 4th Edition.
Otim, G., 2009, Estimation and Tendering Lecture notes, Department of Civil Engineering, Kyambogo
University.
Howard. W.W, Wood. A. A. B., 1981, Practical Builder’s Estimating, 4th Edition.

77

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UGANDA TECHNICAL COLLEGE -LIRA

Department of Civil & Building

HDCE 124 - Estimating & Tendering , Civil Department

HDCE 124 - Estimating & Tendering , Civil Department

CHAPTER ONE ................................................................................................................................................................. 5

HDCE 124 - Estimating & Tendering , Civil Department

• Land rent if applicable

HDCE 124 - Estimating & Tendering , Civil Department

HDCE 124 - Estimating & Tendering , Civil Department

ESTIMATING AND TENDERING.

HDCE 124 - Estimating & Tendering , Civil Department

Contracts without Quantities

Contracts with quantities

HDCE 124 - Estimating & Tendering , Civil Department

Parties involved in Estimating and Tendering

i. Client’s/ promoter’s staff or their professional representatives.

Terms used in Estimating and Tendering

i. Own builder’s work

ii. Own subcontractor’s work

iii. Nominated subcontractor’s work

iv. Nominated supplier

vii. Accurate Bills of Quantity

HDCE 124 - Estimating & Tendering , Civil Department

ix. Approximate BoQs

xi. Prime cost contracts

xiii. Estimate Adjudication

HDCE 124 - Estimating & Tendering , Civil Department

xiv. Consultant’s Estimate

xv. Contractor’s Estimates

xvi. Cost engineering

ASSIGNMENT (READ ABOUT)

All-in rates for resources

1. Acquisition of documents (plans, specification, BoQs, Form of agreement, Conditions of contract)

1. Presentation of the estimator’s report to directors to convert it to a tender.

Techniques / Methods of Estimating

i. Unit rate estimating technique

ii. Operational estimating technique

Other estimating techniques

Types of Cost Estimates for Tendering

o Pre-tender cost estimate (design estimate) – screening,

HDCE 124 - Estimating & Tendering , Civil Department

a) Pre-tender cost estimate (design estimate)

b) Bid/ Tender estimate

• Budget estimate for financing

HDCE 124 - Estimating & Tendering , Civil Department

Understand scope of work Estimating tool Come up with control budget

Execute work as per schedule

Allocating prices as drawn

EXAMPLES OF ESTIMATING USING UNIT RATE TECHNIQUE

HDCE 124 - Estimating & Tendering , Civil Department

Tie wires and spacers 2%

Cutting and bending labour 15hrs per ton

Fixing rate labour 20hrs per ton

Bar bending machinery within on-site cost

Site transportation within on-site cost

Labour for steel fixer 3000 per hr

Wastage of 5% of purchase……………………………… 96,154/

Add 2% of purchase for spacers and binding wires………… 38,462/