Bamboo PDF
Bamboo PDF
Bamboo PDF
CORINNA SALZER
Cover: Two story housing with structural round bamboo in Iloilo, Philippines
Photo: Corinna Salzer
Printed by
Chalmers Reproservice
Gothenburg, Sweden 2016
II
SUSTAINABILITY OF SOCIAL HOUSING IN THE URBAN TROPICS
Thesis for the Degree of Licentiate of Engineering
CORINNA SALZER
ABSTRACT
The Licentiate thesis looks at sustainable building approaches for social housing in emerging
economies. It combines theoretical concepts with practical applications of sustainability and
underlines the relevance and strength of multi-dimensional development. At the example of
the Philippines, the conceptual framework for a multi-perspective development process of a
bamboo-based building system is developed. Sustainability Assessment Criteria are defined
based on data from three stakeholder clusters: (1) Builders and users of traditional bamboo
houses in the Philippines; (2) Stakeholders involved in using forest products for housing in
countries around the world; and (3) Stakeholders in the field of social housing of the
Philippines. Through a qualitative content analysis, research areas are identified and
categorized into five dimensions of holistic sustainability: technology, society, ecology,
economy, and governance. The Licentiate names methods leading to measurable, quantitative
endpoints for those research areas and presents selected results: from mechanical property and
fire resistance testing in the technical pillar, to environmental impact assessment in the
ecological dimension as well as pathways towards a legal approval as contribution to the
governance pillar. An accompanying implementation project is introduced, producing outputs
in economic, social and governance dimension, and a pathway for the course of the PhD is
shaped. By the end of the PhD thesis, a holistic sustainability assessment of the building
technology will be provided for the given context of social housing in the Philippines.
I
II
PREFACE
The thesis summarizes two years of research at the Chair of Sustainable Building at Chalmers
University of Technology in Gothenburg, Sweden. The funding of the research is provided by
Hilti Foundation. The research results are materialized in an application project named Base,
operating in Singapore and the Philippines.
Thanks are extended to my supervising Professor Holger Wallbaum, the colleagues at the
Chair of Sustainable Building, the Chalmers Area of Advance Built Environment profile
ing the research, Base Team Members from the
applied project, the Hilti Foundation Management as well as my family. Fruitful exchanges,
expert and interdisciplinary reflections have supported to shape the thesis and are highly
valued.
Corinna Salzer
Gothenburg, September, 2016
III
IV
LIST OF PUBLICATIONS
The thesis is based on the following appended conference and journal papers:
Journal Papers:
I. Salzer, C. (2015). Sustainability of Social Housing in Asia: A Holistic Multi-
Perspective Development Process for Bamboo-Based Construction in the
Philippines. Sustainability. Status: published January 2016, Authors: Corinna
Salzer; Holger Wallbaum, Luis Lopez, Jean-Luc Kouyoumji
II. Salzer, C. (2015). Environmental performance of social housing in emerging
economies: Life Cycle Assessment of conventional and alternative construction
methods in the Philippines. International Journal of Life Cycle Assessment.
Status: 1st Review - Minor Revisions, Authors: Corinna Salzer; Holger
Wallbaum, York Ostermeyer, Jun Kono
III. Salzer, C. (2015). Determining material suitability for low-rise housing in the
Philippines: Physical and mechanical properties of the bamboo species Bambusa
blumeana. BioResources. Status: Handed-in, awaiting response. Authors: Corinna
Salzer; Holger Wallbaum, Marina Alipon, Luis Lopez
Conferences:
I. Salzer, C. (2015). Preparing for Scale and Impact: Legal approval of bamboo as
structural component in housing of the Philippines. Proceedings of International
Conference on Sustainable Practices in Civil Engineering SPACE. Status:
presented April, 2015, Manila, Philippines (not published in international
database). Authors: Corinna Salzer; Luis Lopez
II. Salzer, C. (2015). Innovation for low-rise construction in the urban tropics.
Proceedings of the International Forum on Urbanism. Status: presented June,
2015, Incheon, Korea. Authors: Corinna Salzer; Clara Hernando Camarasa
III. Salzer, C. (2015). Stories that change the paradigm: Bamboo structures for
sustainable and resilient communities. Proceedings of the World Bamboo
Congress. Status: presented September, 2015, Damyang, Korea. Authors:
Corinna Salzer; Sonia Fardigo; Andrea Fitrianto
IV. Salzer, C. (2015). Fire resistance of low-rise housing in the tropics: Test results for
bamboo-based construction systems. Proceedings of the World Timber
Conference. Status: Accepted for presentation August, 2016, Vienna, Austria.
Authors: Corinna Salzer; Holger Wallbaum; Lily Tambunan
All papers are written by the PhD Candidate with method or data assessment support or
content reflection by the co-authors.
V
VI
CONTENT
ABSTRACT ........................................................................................................................... I
PREFACE ............................................................................................................................ III
LIST OF PUBLICATIONS ................................................................................................... V
CONTENT ......................................................................................................................... VII
PICTURES........................................................................................................................ VIII
TABLES ............................................................................................................................. IX
FIGURES ............................................................................................................................ IX
1 Introduction .....................................................................................................................1
1.1 Background ..............................................................................................................1
1.2 Objectives of PhD and Licentiate..............................................................................3
1.3 Limitations ...............................................................................................................4
2 Method ............................................................................................................................5
2.1 General Part .............................................................................................................5
2.2 Specific Part: Methods of selected research contributions .........................................9
2.2.1 Species Selection and Properties ......................................................................10
2.2.2 Fire Resistance of bamboo-based housing in the tropics .................................. 10
2.2.3 Environmental Impact Assessment .................................................................. 12
2.2.4 Legal Approval for bamboo-based construction methods.................................14
2.3 Supporting Part: Methods of the accompanying implementation project ................. 14
2.3.1 Supply Chain ................................................................................................... 14
2.3.2 Stakeholder participation and capacity building ............................................... 15
2.3.3 Implementation of construction projects ..........................................................16
3 Results .......................................................................................................................... 17
3.1 Species Selection and Properties ............................................................................. 17
3.2 Fire Resistance of bamboo-based housing in the tropics ......................................... 21
3.3 Environmental Impact Assessment ......................................................................... 23
3.4 Legal Approval for bamboo-based construction methods ........................................ 26
4 Discussion and conclusion .............................................................................................30
4.1 Discussion and conclusion: selected research contributions .................................... 30
4.1.1 Species Selection and Properties ......................................................................30
4.1.2 Fire Resistance of bamboo-based housing in the tropics .................................. 31
4.1.3 Environmental Impact Assessment .................................................................. 31
4.1.4 Legal Approval for bamboo-based construction methods .................................33
VII
4.2 Discussion and conclusion: conceptual framework and overall methodology ..........33
5 Future research .............................................................................................................. 34
5.1 Research to deepen specific Licentiate contributions .............................................. 34
5.1.1 Species Selection and Properties ......................................................................34
5.1.2 Fire Resistance Testing of bamboo-based housing in the tropics ...................... 34
5.1.3 Environmental Impact Assessment .................................................................. 35
5.2 Research on additional specific research fields ....................................................... 35
5.2.1 Connections and Building Systems .................................................................. 35
5.2.2 Wind Resistance ..............................................................................................35
5.2.3 Thermal comfort through climate adjusted materials and designs .................... 36
5.3 Research on accompanying implementation project ................................................ 36
5.4 Research on holistic sustainability assessment ........................................................ 37
6 Reference ...................................................................................................................... 38
7 Annex............................................................................................................................45
PICTURES
Picture 1: informal settlement, Metro Manila, Philippines (left) ..............................................2
Picture 2: self-build concrete house, Metro Manila, Philippines (right) ...................................2
Picture 3: Bamboo use today - left: rural, temporary bamboo house ........................................2
Picture 4: Bamboo use today - right: bamboo in informal settlement.......................................2
Picture 5: Specimen installation and furnace at [37] .............................................................. 12
Picture 6: Modern bamboo-based housing built in Iloilo, Region IV in 2015 by [19], [27] ....17
Picture 7: Assessment of Surface Integrity after testing, left: organic, middle: metallic ......... 22
Picture 8: ID3 specimen with organic plaster carrier during test (right) ................................. 22
Picture 9: Removal of protective cover to assess bamboo cross-section after fire (left) .........23
Picture 10: Classification of charring degree on structural bamboo after fire (right) .............. 23
VIII
TABLES
Table 1: Sustainability Criteria ...............................................................................................6
Table 2: Summary of specimen for fire resistance testing...................................................... 11
Table 3: Economically relevant bamboo species in the Philippines [45] ................................ 18
Table 4: Geometric Characteristics of Test Specimen ........................................................... 18
Table 5: Physical properties of B. blumeana ......................................................................... 19
Table 6: Calculation of Characteristic Strength Values for B. blumeana in [N/mm2] ............ 20
Table 7: Summary Characteristic Strength and Permissible Stresses for B. blumeana ...........21
Table 8: Table of Content- Philippine Provisions for cement-bamboo frame technology .......27
Table 9: Coefficient CB (seismic and wind) to calculate minimum length of walls [19], [42] 29
FIGURES
Figure 1: Licentiate and PhD concept in three stages ..............................................................4
Figure 2: Systemic approach to identify of roadmap for technology development ...................7
Figure 3: Systemic research of the PhD from micro to macro angle ........................................8
Figure 4: Systemic approach on PhD research: technical and environmental research fields ...9
Figure 5: Overview: Licentiate Contributions .........................................................................9
Figure 6: Temperature Curve for Fire testing of SNI 1741 / ISO 834-1 ................................. 11
Figure 7: Constructive Details for specimen with metallic plaster carrier .............................. 12
Figure 8: Visualization of the Building Envelope: 1 story house (FE), 25m2, 25a service life 13
Figure 9: Life Cycle Phases according to [40]: light- empirically validated, dark- scenarios..13
Figure 10: Systemic approach of implementation project: supply chain development............15
Figure 11: Systemic approach of implementation project: involvement & capacity building .16
Figure 12: Systemic approach of implementation project: construction projects .................... 17
Figure 13: Min / Max thermocouple reading of specimen with two types of plaster carrier ...21
Figure 14: Test reading of thermocouples of selected specimen during testing ...................... 22
Figure 15: Scheme showing effect of plaster layer on fire unexposed side of specimen .........23
Figure 16: Comparison of construction technologies in Phases A-B-C-D, GWP (100 years) .24
Figure 17: Bamboo House Types per inflow category, Phases A1-A5, GWP (100 years) ...... 24
Figure 18: Comparison Phases A-B-C-D, GWP (100 years) | CED | Impact2002+ in [%] ..... 25
Figure 19: Comparison Min | Base Case | Max technologies, Phases A1-A5, GWP (100a)....25
Figure 20: Scenarios: Service life of houses, Phases A-B-C-D, GWP (100 years) ................. 26
Figure 21: Plastered cement-bamboo frame system based on [19], [43] ................................ 28
IX
X
1 Introduction
The introduction is organized in three subchapters, providing the background of the research
field, deriving general and specific research objectives, and describing limitations.
1.1 Background
1
Picture 1: informal settlement, Metro Manila, Philippines (left)
Picture 2: self-build concrete house, Metro Manila, Philippines (right)
The use of locally available raw materials is a potential to be explored in this regard. With the
Philippines being country for research and application, one material with interesting potential
is the fast growing, widely spread bamboo. Since centuries, traditional bamboo housing can
be found in the rural Philippines [14]. The use of bamboo in rural Philippines is mostly of
temporary nature. In urban Philippines, it is limited to informal settlements and non-load-
bearing applications. In Picture 3 and 4 typical examples for both rural and urban applications
of bamboo in the Philippines are shown. In cities, a common perception is that conventional
concrete and steel building methods are more modern, safe, and less maintenance intensive.
2
1.2 Objectives of PhD and Licentiate
Traditional bamboo construction has never undergone a holistic review to assess its adaptation
potential to an urban and/or disaster prone context. The general objective of the PhD is to look
at the raw material bamboo strategically and assesses its potential to be an acceptable, viable
solution for permanent, sustainable and resilient housing. For this to be achieved, the PhD
names three stages to be conducted in consecutive order:
1. To develop a conceptual framework for bamboo-based housing in social housing
sector by identifying sustainability criteria for its assessment in this context and
deriving a research and implementation roadmap enabling the assessment according to
the identified sustainability criteria.
2. To generate scientific results along the defined research roadmap, hand-in-hand to an
implementation project accompanying the PhD. The objectives of this stage are
described as specific objectives of the PhD.
3. To use the concept of sustainability as a decision-tool, as suggested in [15],
conducting a holistic sustainability assessment based on the results of the roadmap.
The Licentiate will focus on stage one and selected items of stage two. The PhD will cover
stage one and two and conclude with the holistic sustainability assessment of stage three.
The activities of stage two are clustered into five pillars of sustainability: Ecology, Society,
Economy, Technology and Governance. In line with most common definition of
sustainability [16], the pillars society, environment, and economy are denominated. It is
noted, that all three pillars will be enforced in this work. Therefore weak sustainability,
weighing two dimensions over the third, as commonly applied in sustainability decisions of
the last decades, is discouraged. Moreover, the given context requires additional pillars to be
considered: When dealing with products or product comparison, such as in [17] or this thesis,
the technical performance is a critical dimension and demands inclusion. Further, especially
in development cooperation, the relevance of governance has to be highlighted, as done in
[18], to enable impact at scale. Both dimensions, technology and governance, are critical to
bridge the gap between a theoretic approach and materialization of sustainability decisions.
The definition of sustainability applied in this PhD is therefore named holistic sustainability.
Results are generated through research and through an implementation project, both of
which will go hand-in-hand and provide feedback loops to each other. The pillars Ecology
and Technology contain mainly research activities covered partially at the stage Licentiate
and fully through the PhD. The pillars Society, Economy and Governance contain mainly
activities of the implementation project. The organizational set-up of the implementation
project is an initiative of Hilti Foundation named Base. Through a headquarter in Singapore,
Base Builds, and an operational entity in the Philippines, Base Bahay [19], bamboo-based
construction projects are implemented which make direct use of the research contributions off
the PhD. The need for a holistic interpretation of sustainability in this PhD is enforced
through the striking distance of research and application.
Figure 1 summarizes the contribution of the Licentiate thesis according to above mentioned
principles.
3
Figure 1: Licentiate and PhD concept in three stages
1.3 Limitations
The thesis covers a general methodology and selected one-dimensional research results.
Further one-dimensional results will be added within the course of the PhD and merged into a
holistic technology assessment at the end of the PhD.
4
2 Method
The Method chapter of the Licentiate thesis is differentiated into a general, a specific and a
supporting part. The general part, 2.1, is connected to the general objective stage one, in
which a conceptual framework is provided through the definition of sustainability criteria
based on which a research and implementation roadmap is derived. Consecutive, in 2.2,
specific objectives of the roadmap are defined. In 2.2.1, methods of selected research
contributions of the roadmap are described. Further, in 2.2.2, methods applied in the
supporting implementation project, which go hand-in-hand with the research contributions,
are introduced. Latter are however not in the focus of the Licentiate thesis, but mentioned to
provide a comprehensive overview.
Stakeholder requirements are captured through cognitive interviews for which the interview
principles for research and evaluation of [23] were followed. The interviews generated
qualitative data on requirements, barriers and opportunities from multiple stakeholder
perspectives. Depending on the background and context of the stakeholder group, either a
less-formal/-structured Ethnographic Interview type, or an Interview Guide Approach was
chosen. In addition to interview data, Field Inspections or Direct Observations were carried
out over the period of the Licentiate. Barriers and opportunities, expressed by stakeholders or
5
documented in field observations, were transformed in a qualitative Content Analysis to elicit
most suitable sustainability criteria for the given case.
As first level sorting, a barrier or opportunity was coded into one or several pillars of
sustainability.
As second level sorting, several sampling strategies, described in [24], were applied to
identify common patterns in the qualitative data: (1) Group characteristic sampling,
identifying patterns for several stakeholders in a group without neglecting their
diversity, (2) Instrumental-use multi-case sampling, for generating actionable, useful
findings, and (3) Comparison-focused sampling, for understanding similarities and
differences between cases that can be compared to the present case.
As third level, Literature review and field observations, where available, were used to
triangulate identified requirement patterns.
The content analysis then derived Sustainability Criteria from the identified patterns. This part
can be described as Analytic Induction, as it moves from existing concepts to generating a
new, case-specific framework. Table 1 below states the identified context specific
Sustainability Criteria:
Table 1: Sustainability Criteria
No. Pillar of Sustainability Criteria
Tech- Gover-
Society Economy Ecology
nology nance
1 Social acceptance & advocacy
2 Participation & identification
3 Capacity building
4 Income at local value chain
Maintenance & incremental
5
development
6 Health & comfort
7 Enduring safety & performance
8 Standardization, quality control, pace
9 Continuous innovation
10 Cost advantage of houses
11 Scalable business model
12 Supply accessibility
13 Supply availability & sustainability
14 Environmental impact
15 Compliance to policies & regulations
Four strategies were found being research about and implementation of building concepts,
sustainable supply chain development as well as stakeholder involvement and capacity
building. An explanation is given in the following: The scientific work of the PhD focuses on
research about the building technology. At its core, it analyzes the technical potential of the
raw material round bamboo and building concepts using it and provides transparency on its
6
environmental performance compared to the conventional construction solutions. In addition,
the implementation of the building concept is a critical contribution to this PhD. As shown in
[25] for several countries in Asia, it is deemed a crucial strength of sustainability indicator
programs, when they are anchored in long-term implementation strategies. A corresponding
implementation project targets to develop people-centered, participatory construction pilots,
the creation of ownership and identification of the local population with the said technology, a
legal framework in the country of application, sustainable supply chains and economic scale-
up strategies. The importance of developing a technology people-centered and along of
[13], [21], [26] and
institutions such as [27]. For the application of a forest product based technology at larger
scale, a specific requirement is a sustainably generated, accessible supply of quality graded
raw material. In many economies of bamboo growth, a bamboo supply chain has to be built-
up first [28].
Guided by the four strategies and 15 Sustainability Criteria, action items across the five pillars
of holistic sustainability were derived as shown in Figure 2. Each roadmap item is connected to
one or more methods to obtain measurable outputs.
7
In the following more detail is provided about the PhD relevant research strategy. Through a
systematic assessment from micro to macro scale, the PhD analyzes whether a building
concept can be developed performing in the five dimensions of holistic sustainability. A
comprehensive technical understanding from material- over system- to building-scale, allows
evaluating compliance of a previously none-defined forest product with the requirements of
an urban built environment. By ensuring that all compared technologies are able to satisfy
legal standards and building codes for permanent houses, a direct comparison with existing
conventional solutions is enabled. A visualization of the different layers of research can be
found in Figure 3.
System-Scale: In order to maximize the raw material strength as well as to cope with its
weaknesses, critical elements for technical performance are structural connections.
Connections have to satisfy cost and maintenance criteria, as well as skill demand,
modularization, and implementation pace. Further, the resistance of the building system to fire
impact and lateral forces is tested on system level to ensure durable performance.
8
All results on material, system, and building scale enable the formulation of a concept for the
legal approval of the building method in the Philippines. In Figure 4 the research roadmap is
visualized.
Figure 4: Systemic approach on PhD research: technical and environmental research fields
For the Licentiate, selected research results will be presented. These are species selection and
properties, fire resistance, Environmental Impact Assessment and legal approval. The
graphical visualization of Figure 5 summarizes the contribution of the Licentiate. By the end
of the PhD, above research roadmap is targeted to be completed.
9
literature study, material testing in laboratory, to calculation with and without simulation
software. Material scale testing was conducted with the raw material round bamboo. Fire
resistance was tested on system scale. On building scale, environmental impact assessment
and the framework for a legal approval as building concepts are introduced . For each of the
research topics, specific one-dimensional quantitative testing methods are identified to
generate data with scientific validity as well as local and financial applicability for the given
context.
10
SNI / ISO Temperature Curve and Thermocouple reading at furnace
1000
Temp at Thermocouple [°C]
800
600
400
200
0
0 5 10 15 20 25 30 35 40 45 50 55 60
Time [minutes]
Figure 6: Temperature Curve for Fire testing of SNI 1741 / ISO 834-1
Due to the unavailability of a test stand in the Philippines, it was deemed acceptable to test
with a different structural bamboo of similar geometric characteristic and chemical
composition, since the focus of this testing was to prove performance as system response, not
of round bamboo alone. The specimens for testing used the bamboo species Gigantochloa
Apus, available and common in Java, Indonesia. Java, the island of Indonesia with the largest
population of approximately 145 million inhabitants [7] is an attractive housing market too.
The bamboo species was chosen because of its structural characteristics, its affordability and
availability in Java. Gigantochloa Apus has a typical diameter of 80-100mm and a minimum
wall thickness of 8-12mm in the structurally deployed part of the bamboo pole, and is
therefore comparable to B. blumeana in the Philippines.
Bamboo wall cross-sections were tested with specimens of 1050mm by 1050mm and
evaluated according to insulation, integrity and mechanical resistance criteria, as required for
elements with separating and load-bearing function. In Figure 7 and Picture 5, the specimen
specification, a picture of the fabricated specimen as well as the furnace for testing, are
shown. Through configuration testing, the following variables and their effect on the
performance of the wall system were evaluated: (1) Effect of fire retardant on round bamboo,
(2) Anchor options to fix protective cover in bamboo, (3) Type of plaster carrier, (4) Plaster
thickness, (5) Plaster composition, (6) Usage of additives in plaster, and (7) Existence of one
or two layers of the protective cover. For norm testing only the variables 3 and 7 were varied
according to Table 2 below.
Table 2: Summary of specimen for fire resistance testing
No Plaster carrier Cover
Type A: Organic One layer
1
Type B: Metallic
2
Type A: Organic Two layers
3
Type B: Metallic
4
The other variables were fixed with the following explanation:
Plaster thickness: The cement plaster acts as fire protection material. Its thickness is
critical for the protection time and was designed according to protective function needed
to maintain a minimum allowable bamboo cross section after 60 minutes of fire
exposure. The failure time of protection is assumed through simplified factor of 1.4
multiplied with the thickness in mm as suggested in [32]. To balance protective function
with dead weight of the plaster, a 25mm plaster was applied.
11
Given the social housing context, in which a most conservative, affordable and simple
specimen configuration is required to reflect the affordability criteria, the following as
decided:
Plaster composition: A standard plaster mixture was chosen without use of additives.
No fire retardant on round bamboo: The surface treatment of bamboo has indicated
positive effects, but requires more in-depth studies including economic effects.
Standard anchors: To fix the cover in the structural bamboo, common nails were used.
Special screws or anchors were excluded.
12
are not only measured up to the construction of the houses, but throughout its life cycle on
Cradle to Grave perspective.
Through an inventory analysis all mass and energy flows throughout the lifespan of a
functional equivalent (FE) are accumulated, with the FE being a typical one-story social
housing unit with a 25-m2 floor plan as displayed in Figure 8.
Figure 8: Visualization of the Building Envelope: 1 story house (FE), 25m2, 25a service life
Life cycle assessment models are implemented and evaluated with the software SimaPro,
using the single-impact indicators global warming potential (GWP), from the International
Panel for Climate Change (IPCC), and cumulative energy demand (CED). The latter provides
a good general indication of LCA results [39]. The first, is one of the most frequently used
single impact indicator and retrieves savings of CO2 equivalents [11]. Both indicators are
recommended by [40]. Results are presented according to the Life Cycle Phases defined in
EN 15978, stated for Phases A-B-C-D and with boundary conditions defined as Base Case.
Figure 9 summarizes for which Phases empirical data or scenarios were applied.
Figure 9: Life Cycle Phases according to [40]: light- empirically validated, dark- scenarios
The Phases B1 and B5-B7 are excluded from the assessment with reasons being the
following: Emissions captured during Phase B1 are neither for well-studied exemplary
projects nor for social housing documented and should be studied for future inclusion.
Refurbishment (B5) was excluded as unlikely in the informal context. The effect of changes
in indoor comfort and associated energy use in Phases B6 and water use in B7 has yet to be
quantified and understood in detail, and was therefore omitted at this point in time of the
assessment. Theoretical models for Phases A1-A5 are verified with three years of empirical
data from construction projects. Phase B, C and D scenarios capture the realities of an
emerging economy, through inputs of intensive field research and expert interviews.
13
2.2.4 Legal Approval for bamboo-based construction methods
This contribution is of governance nature and looks at building scale.
To implement a building code for bamboo-based construction in the Philippines and to carry
out advocacy on policy level and in professional organizations, are objectives for the
Governance dimension. It will enhance nation wide acceptance by academe, governments,
communities in need of housing, and the private sector. In the following the method for
formulation of the draft building code is described. The drafted code is named: Philippine
Provisions for cement-bamboo frame houses of one and two stories being discussed as
additional chapter to the National Structural Code of the Philippines (NSCP),
Volume 3: Housing [41]. The design provisions recommended in the draft document are based
on the results of the research roadmap and will be reviewed by the Association of Structural
Engineers of the Philippines (ASEP) and responsible government institutions. The structure of
the document is based on NSCP, and Chapter E and G of the Colombian Code for Seismic
Resistant Residential Buildings (NSR-10 2010) [42]. Author rights of NSR-10 belong to the
Asociación Colombiana de Ingeniería Sísmica (AIS). Its utilization for the purpose of
adaptation to the Philippines was granted for the draft formulation. The document contains
further provisions of Peruvian Technical Norm NSR-1 (E.100) from the Ministry of Housing,
Construction and Sanitation of Perú (MHCS) [43].
14
In summary of Figure 10, the implementation project distinguishes between the following
supply related activities:
In summary of Figure 11, the implementation project distinguishes between the following
stakeholder related activities:
15
Figure 11: Systemic approach of implementation project: involvement & capacity building
16
Picture 6: Modern bamboo-based housing built in Iloilo, Region IV in 2015 by [19], [27]
In summary of Figure 12, the implementation project names the following construction
project related activities:
3 Results
This chapter compiles selected research results, being named on the research roadmap and
obtained during the Licentiate. The following research items have been selected: Species
selection and properties, fire resistance, Environmental Impact Assessment and legal approval
for building methods. The contributions to the PhD go along with outputs on actual
construction, supply chain and stakeholder involvement of an implementation project. Results
of latter will be presented at PhD level and contribute to a five-dimensional holistic impact
assessment.
3.1 Species Selection and Properties
The chapter summarizes the species selection and the physical and mechanical properties
obtained from testing one bamboo species.
SPECIES SELECTION
A crucial step is the selection of a bamboo species for construction. Globally, more than 1200
bamboo species are recorded. On a country level, the Philippines Forestry Sector identifies
17
around 62 different species [44]. A short-list of nine economically relevant species was
identified for the Philippines [45], as stated in Table 3.
Table 3: Economically relevant bamboo species in the Philippines [45]
Latin Name Researcher Local name
Bambusa blumeana J.A. & J.H. Schultes Kauayan-tinik
Bambusa vulgaris Schrader ex. Wendland Kauayan-kiling
Dendrocalamus asper (Schultes f.) Backer ex. Heyne Giant bamboo
Bambusa merrilliana or (Elmer) Rojo & Roxa or Bayog
Dendrocalamus merillamus (Elmer) Elmer
Gigantochloa atter (Hassk.) Kurz Kayali
Gigantochloa levis (Blanco) Merr. Bolo
Schizostachyum lima (Blanco) Merr. Anos
Schizostachyum lumampao (Blanco) Merr. Buho
(Gamble) McClure Laak
Bambusa philippinensis or
(Gamble) Dransfield
Sphaerobambos philippinensis
From the list of economically important species, a highly promising species is Bambusa
blumena (B. blumeana). It is the most abundantly available bamboo species in the Philippines,
and represents therefore a promising potential for cost-efficient buildings. Its empirical use for
traditional houses and its affordability make it a bamboo species of interest to the given
context [33]. B. blumeana is the species most widely grown throughout all regions of the
Philippines. It can be found growing along river banks, hill slopes, and freshwater creeks and
tolerates flooding conditions. It is commonly planted in settled areas at low and medium
altitudes. Being native to Java, Indonesia, and Eastern Malaysia, it is cultivated in Southern
China, Malay Peninsula, Moluccas, Philippines, Sumatra, Borneo, India and Indochina[44].
Previous scientific studies indicated that 3-4 year-old B. blumeana has a high relative density,
compressive strength and modulus of elasticity in static bending [46]. A modification of the
American Standard ASTM D143-52 Standard Methods of Testing small clear specimens of
Timber [47] has been applied, given the absence of a global bamboo standard at the time of
the study. Results from these studies are difficult to compare to other bamboo species due to a
lack in uniform test procedure, but provide first insights about the potential suitability of the
species. The hypothesis of its technical suitability is further supported through the identified
traditional use for vernacular buildings [48]. Although no commercial unit prices exist for
bamboo in the Philippines, an evidence of B. blumeana`s affordability is that until today a
high share of low income groups use it for their temporary housing [19], [49].
PHYSICAL PROPTERTIES
The geometric dimensions of the tested bamboo culms are basis for the physical and
mechanical properties and therefore summarized in Table 4.
Table 4: Geometric Characteristics of Test Specimen
Test Specimen Region IV
Height Diameter Wall Thickness
[mm] [mm]
Butt 78 104 19 27
94.0 24.0
Middle 81.3 109.2 7.6 14
91.2 10.0
Top 70.6 96.5 6.2 7.6
80.9 7.0
18
The physical property measurements and an ANOVA assessment have proven a significant
trend for Moisture Content decrease from the butt to the top. Relative density significantly
increases from butt to top with an average density of 570 kg/m3. Shrinkage of the culm wall
thickness from green to oven-dry condition was 6.61, 8.81 and 4.01% at the butt, middle and
top, respectively. The shrinkage at wall thickness was higher than of the circumference with
6.33 to 5.13%. Shrinkage longitudinal was minimal, with approximately 0.5% at butt and
middle and 0.2% at the top of the test culm. Table 5 summarizes the Physical properties of B.
blumeana.
Table 5: Physical properties of B. blumeana
Physical Height Test Specimen Region IV
Properties Mean Range of
Value Values
Moisture Content Butt 97.55 74.17 - 121.47
(%) Middle 75.44 60.76 - 92.19
Top 62.14 36.89 - 84.23
78.38
Relative Density Butt 0.517 0.423 - 0.607
Middle 0.559 0.440 - 0.639
Top 0.634 0.500 - 0.766
0.57
Shrinkage Wall Butt 6.16 2.52 - 10.29
Thickness (%) Middle 8.81 3.31 - 19.82
Top 4.01 0.88 - 8.98
6.33
Shrinkage Butt 3.56 2.40 4.97
Outside Middle 6.59 3.78 19.82
Diameter (mm)
Top 5.24 4.25 6.32
5.13
Shrinkage Length Butt 0.546 0.138 -1.737
(mm) Middle 0.516 0.080 - 0.947
Top 0.193 0.042 - 0.600
0.418
MECHANICAL PROPERTIES
The compressive and tension strength along the grain and Modulus of Rupture increases from
butt to top of the culm, along with the increase of density towards the top. Latter explains the
increase in strength [50], [51]. The characteristic compressive strength is in the range of
softwood species. The obtained bending strength values are characteristically high and
underline bamboos remarkable flexibility. The shear strength slightly increases towards the
top, while no significant difference between middle and butt were observed. Latter holds true
both for specimen with nodes and internodes. The existence of a node does not increase the
shear strength, but showed lower results. The internode tensile strength significantly increases
from butt to top while in the node the increase is not significant. Tensile strength at the node
was lower than the internode. The lower values on shear and tensile strength of B. blumeana
19
at the node can be explained with previous scientific research on other bamboo species.
According to [52], fibers in a node are interrupted by crossing vessels going into the
diaphragm inside the node. In [53] it is explained that the mechanical elasticity is reduced due
to the shorter, thicker and forked fibers in the nodal part, thus bamboo culms under tension
often break at the node. This has been confirmed in the failure modes of the tension specimen
failing in the node itself. B. blumeana`s strength in compression along the grain, tension along
the grain and bending underline the potential for construction, which was identified earlier for
bamboo species from other parts of the world such as [50], [54]. Its weakness in shear
strength provides guidance on connection and system design.
Table 6 shows the calculated characteristic strength based on the raw data of B. blumeana.
Table 6: Calculation of Characteristic Strength Values for B. blumeana in [N/mm2]
Compressive strength Tensile strength Description
parallel to the grain [N/mm2] parallel to the grain [N/mm2]
Top Middle Bottom All Top Middle Bottom All Area of the bamboo pole
m 40.6 37.4 31.2 36.4 187.6 174.1 126.5 162.3 Mean
s 5.4 9.0 6.9 8.0 45.7 33.1 22.1 43.2 Standard deviation
f0.05 34.0 24.7 22.0 22.5 128.3 127.5 101 104.7 5% percentile
Number of samples
n 10 10 10 30 19 20 20 59
tested
fk 30.1 19.6 17.8 20.0 108.9 112.9 90.3 95 Characteristic strength
In the left column of Table 7, the characteristic strength values for B. blumeana bamboo are
stated as obtained from the testing, in the right column recommended permissible stresses are
20
written. In line with the limit state design principle, permissible stresses for using B.
blumeana bamboo in low-rise construction in the Philippines were derived by dividing with
safety factors. Given the natural variability of bamboo, conservative safety factors are
recommended. A conservative safety factor of 4.5 is taken into account for permanent loads,
which is in line with ISO 22156 [29] and conservative compared to Eurocode 5 [32]. Latter
can be reduced for loads of short durations.
Table 7: Summary Characteristic Strength and Permissible Stresses for B. blumeana
Property Characteristic Strength Permissible Stress
Symbol Value (MPa) Symbol Value (MPa)
Compression strength parallel to grain fc,0,k 20 fc,0,adm 8.0
Bending strength fm,k 34.6 fm,adm 7.7
Shear strength fv,k 5 fv,adm 1.1
Tension strength parallel to grain ft,0,k 95 ft,0,adm 21
Modulus of Elasticity Mean Emean 13100 Emean 13100
th
Modulus of Elasticity 5 percentile E0,05 8600 Emin 8600
Density - Mean mean 570kg/m3 mean 570kg/m3
The results obtained after one-hour fire impact and documented according to the
categories Insulation (I), Integrity (E) and Mechanical Resistance (R).
Insulation (I): Figure 13 displays the temperature increase over time on the unexposed side of
the construction. All tested specimens received an insulation fire rating of 60 minutes.
Maximum reading of a thermocouple at the fire unexposed side was 80°C after 60 minutes,
with other thermocouples ranging from 50°C upwards depending on the thermocouple
location. 80°C is clearly below maximum allowable temperatures according to norm of 140°C
(average) and 180°C (max). Graph x shows the maximum and minimum thermocouple
reading for specimen ID1 (organic plaster carrier) and ID2 (metallic plaster carrier). Specimen
ID1 had an additional insulating effect compared to ID2 as well as a less rapid temperature
rise due to the insulating effect of the organic plaster carrier. Given that both specimens
performed sufficient, insulation was not deemed a critical variable for the wall system.
Thermocouple reading of specimen ID1 (dashed line) and ID2 (solid line)
80
Temp at Thermocouple [°C]
70
60
50
40
30
20
0 5 10 15 20 25 30 35 40 45 50 55 60
Time [Minutes]
Figure 13: Min / Max thermocouple reading of specimen with two types of plaster carrier
Performance of specimens ID3/4 was more conservative in comparison to ID1/2 in regards of
their insulation properties. Temperature readings increased more rapid and already after
21
10 minutes of testing, while ID1/2 specimens only showed temperature rise after 20 minutes.
A maximum temperature of 100°C after 60 minutes was obtained. Since the results for ID3/4
specimens remained in allowable temperature range, it was assessed uncritical provided that
the specimen with one layer protection is exposed to fire from its protected side. The
behaviour of specimen ID1/3 is displayed in Figure 14.
Thermocouple reading of specimen ID1 (dark solid line) and ID3 (light solid line)
100
Temp at Thermocouple [°C]
80
60
40
20
0 5 10 15 20 25 30 35 40 45 50 55 60
Time [Minutes]
Integrity (E): The integrity of all specimens was maintained during the period of testing. No
flame-spread on the fire unexposed side occurred, neither for specimen ID1/2 nor for ID3/4.
An assessment of the fire-exposed and unexposed surfaces during and after the testing
indicated however a different behaviour between ID1/3 and ID2/4 respectively. Under impact
of fire, the specimen ID1/3 encountered strong cracking and partial flaking of plaster portions.
The occurrence of wider cracks at the fire exposed surface increased the risk of linear heat
peaks. Both effects were significantly reduced with specimens ID2/4. The visual assessment
of the crack pattern and crack width indicated less cohesion between the organic plaster
carrier and its plaster cover. Picture 7 show left specimen ID1 and right specimen ID2. The
appearance of cracks was also observed during the testing from the fire unexposed side of the
specimen, as shown in Picture 8.
Picture 7: Assessment of Surface Integrity after testing, left: organic, middle: metallic
Picture 8: ID3 specimen with organic plaster carrier during test (right)
For the specimen ID3/4, where structural bamboos are unprotected at the unexposed side, the
existence of a plaster layer at the unexposed side was an important feature to suppress flame
spread and fulfil integrity criterion. In that way, no flame spread occurred during 60 minutes
although the structural bamboo partially started to be affected by fire from the exposed side,
as visualized in Figure 15.
22
Figure 15: Scheme showing effect of plaster layer on fire unexposed side of specimen
Critically, it has to be mentioned that possible effects of reduced penetration depth of anchors
holding the cover due to starting charring of the bamboo were less visible when testing
without load and only a post testing assessment enabled its evaluation. According to [32], a
minimum anchorage penetration of 10mm is required for timber structures. If this requirement
is followed for bamboo with a typical bamboo wall thickness of 10mm, any kind of charring
would be equal to a failure, although structural capacity would allow for a reduced cross
section.
Mechanical Resistance (R): Since the test stand at [37] did not provide testing under load, the
mechanical resistance was assessed through determination of the effective cross section of
bamboo after 60 minutes fire exposure as shown in Picture 9 and Picture 10. Testing under
load is recommended as described in the respective standards. Although different levels of
charring were identified for specimen ID1/2 from no charring to punctual, linear or regional
charring of up to 5mm, the load bearing capacity of bamboo poles after fire impact remained
sufficient according to the criterion Ed < Rd. Classifications of charring degrees and
calculations of the respective effective cross-sections as well as corresponding compression
test results are provided.
Picture 9: Removal of protective cover to assess bamboo cross-section after fire (left)
Picture 10: Classification of charring degree on structural bamboo after fire (right)
To be highlighted are that the increased organic matter of specimen ID1/3 caused longer
smoldering periods and enabled higher flame spread across the wall than specimen ID2/4.
Both characteristics are a critical risk factor for the mechanical resistance of the wall
assembly and favour specimen ID2 over ID1. For specimen ID1/2 a second layer of 25mm
plaster enhances the compartmentation, however, since structural bamboo in the wall center
starts charring after the failure time of layer one, the second layer acts only for fire protection
from both sides of the walls, but does not increase the protective function.
Figure 17: Bamboo House Types per inflow category, Phases A1-A5, GWP (100 years)
24
To verify the general validity of results obtained with use of the single-impact indicator GWP
(100-year horizon), two indicators were added, i.e., CED and the multi-impact indicator
IMPACT2002+ as shown in Figure 18. The application of these indicators, as shown below,
generally validated the magnitude of environmental reduction with maximum variations of
below 12% across the indicators. The CED showed slightly stronger impacts for the
alternative construction methods coconut panel with a difference of +8.0% from GWP to
CED and +6.5% from CED to IMPACT2002+ for the plastered bamboo technology. The soil-
cement technology was evaluated -11.2% with CED compared to GWP.
Figure 18: Comparison Phases A-B-C-D, GWP (100 years) | CED | Impact2002+ in [%]
To understand the relative contributions of individual inflows, accumulated impacts were
broken down into inflow categories. Based on study of the supply, production and
construction processes, scenarios A1 A5 were formulated and their influences on overall
accumulated impact assessed. Twenty sensitivity analyses were performed for the three
alternative building technologies at the A1 A5 level. All sensitivities were grouped into
scenarios of the minimum and maximum environmental contribution per building technology.
Figure 19 presents results of these scenarios compared with the initial base case. The
environmental reductions of bamboo houses varied from 73-87%, soil-cement houses from
27-47%, and coir houses from 80-83%. The obtained ranges showed that even in the low
performance cases, the alternative technologies remain reducing the environmental impact.
Figure 19: Comparison Min | Base Case | Max technologies, Phases A1-A5, GWP (100a)
Based on the above insights, the base case assumptions are believed to have low uncertainty.
However, it guides future improvements effectively: For example, the roofing material
galvanized iron contributed 41% 46% to bamboo structures. A change to concrete shingles,
25
would reduce the environmental impact as much as 10%, is however not applied in the
Philippines.
The effect of the building lifespan was studied in two scenarios, keeping the RSP at 25 years.
The results are visualized in Figure 20. In scenario one (10 years for all alternatives, 25 years
for conventional), environmental impact of the bamboo technology was 55% of a social house
made of concrete, while the soil-cement block house was already 53% exceeding the
conventional solution. The comparative advantage for plastered bamboo was greatly reduced
in scenario two, at only 16.2% (10 years for bio-based structures, 40 years for block-based).
The same ecological performance was obtained for bamboo buildings with a life span of 10
years and concrete buildings of 50 years at RSP 25 years.
Figure 20: Scenarios: Service life of houses, Phases A-B-C-D, GWP (100 years)
26
Table 8: Table of Content- Philippine Provisions for cement-bamboo frame technology
27
Figure 21: Plastered cement-bamboo frame system based on [19], [43]
The frame is made of bamboo, a combination of bamboo and wood or bamboo, wood and
metal flat bars. The framework contains two horizontal rails, a bottom rail and a top rail, and
studs or vertical elements, connected to the horizontal elements with nails or threaded rods.
The outer frame, defined by the bottom and top rails and two external studs, can be built
entirely with bamboo or sawn wood. The rest of the frame is generally made from bamboo.
The frame has braces to resist to lateral forces.
The cover of the frame is made from two main components: (1) A plaster carrier and (2) the
actual plaster. As plaster carrier either a chicken wire nailed to flattened bamboo or on wood
sheathing or an expanded metal mesh is used. The plaster carrier must be anchored to the
studs. For rib lath mesh nails are sufficient. For flattened bamboo and chicken wire, additional
soft iron wire is used braided between the nails.
The individual walls are transferring vertical and lateral loads and provide a combined action
through being anchored in diaphragms in their bottom and top. The resistance of the structure
is achieved through the following mechanisms:
(a) Sufficient structural walls in both axis of the floor plan to provide resistance against
horizontal seismic and wind loads, taking the longitudinal stiffness of each wall into
account. Structural walls serve to transfer their own gravity forces, resist the lateral forces
parallel to their own plane and vertical forces from the level where forces are generated to
the foundation. Structural walls must be designed following the provisions stated.
(b) A diaphragm system (foundation, intermediate floor or roof) that ensures the combined
action of the structural walls and a load distribution to each wall. The connection between
walls and diaphragms has to be designed according to the specifications given.
(c) A foundation system that transfers all loads from the walls into the ground. The
foundation system must have an appropriate stiffness, so that differential settling is
prevented. The foundation has to be designed according to the specifications stated.
28
The minimum length of walls in each direction must satisfy Equation 1:
Equation 1: Minimum length of walls in each direction
Where:
Li = Minimum length of the sum of all walls w/o openings in direction i
CB = Coefficient for bamboo frames: larger CB, depending on the acceleration expected at the location
Ap = Floor plan size (in m2) of a one story house or for the second floor of a two story house.
Ap2 = Floor plan size (in m2), of a ground floor of a two story house. If the floor does not consist of heavy material like
cement (the value of Ap, r relates to the intermediate floor) a reduction of 0.66*Ap can be applied.
For the calculation of Equation 1, the bamboo coefficient CB, for seismic and wind, is
needed. It can be found in Table 9, calculated for Philippine design loads.
Table 9: Coefficient CB (seismic and wind) to calculate minimum length of walls [19], [42]
Seismic risk Z CB,seismic Wind Zone Design Wind speed (km/h) CB,wind
Zone 4 0.40 0.25 III 250 0.50
Zone 2 0.20 0.16 II 200 0.31
I 150 0.18
Note: The values of CB,seismic were calculated for each region described in the NSCP. Assumed
are walls with plaster cover on both sides for a conservative maximum mass of the walls. The
nearest fault line was assumed, being Type A with < 5km distance. The values of CB,wind were
calculated for Terrain Roughness Type D, exposure Type D multiplied with the Importance
Factor IV according to the NSCP 2010 [57].
29
4 Discussion and conclusion
This chapter develops from a discussion and conclusion about one-dimensional research
results to a discussion of the overall conceptual framework developed for the Licentiate. It
will end with a conclusion about the overall conceptual framework of the thesis.
In addition to the active resistance of the building system, a passive protection through risk
reduction is recommended for bamboo-based housing projects. Structures using round
bamboo for load transfer are to be embedded in a holistic fire safety concept, including set-
backs between houses, minimum requirements for safe electrical wiring, behavioural trainings
for inhabitants and a general firefighting concept for settlements with a relevant share of
houses made from organic matter. Such fire safety concepts have to consider realities in
settlements of rapidly growing urban centers in Asia, Latin America and Africa.
31
In EN16485 carbon neutrality is discussed for biogenic products modelled in LCA. It
is argued that bamboo has special growth characteristics, which justify the carbon
neutrality assumption: In the Philippines, bamboo grows along river banks and sloping
land, not attractive for agricultural use or land development. Philippine Government
noted this potential and promotes it for erosion control on unfertile or risky lands.
Land competition and loss of biodiversity are therefore only scenarios on very large
scale. Bamboo clumps have a limited natural size and poles decay after few years to
allow reproduction. Therefore, poles can be harvested without reduction of existing
stocks, providing farmers annual reoccurring income [60].
The use of organic raw materials in long-lasting products raises the question of
biogenic carbon storage, which has become a frequent topic in recent scientific
publications [61] [64]. In essence, credits are addressed for a delayed release of
carbon into the atmosphere in Phase D. Although there is common sense about
determining short-term and long-term emissions distinctly, there is no consensus on
how to weigh such emissions [65]. In a recent scientific investigations, it was
[66], is
recommended [67]. The IPCC GWP indicator removed consideration of biogenic CO 2,
given the argument that emissions will re-enter the atmosphere sooner or later [68] and
that crediting is not in line with [11] global mass balance and provisions of the [69],
based on precaution.
The assumption of extra carbon sequestration in additional global forest areas, as
suggested in [67], is only justified when an increase in product application is likely
within a stable industrial setting. Because development of a bamboo-based industry in
the Philippines is connected to very uncertain variables, no land-use change
assumption was included.
No local facilities for industrial-scale heat recovery or recycling in the reference year.
The LCA models were chosen to be conservative by not considering potential benefits
beyond the building life cycle.
- -
32
These results must be seen in light of technical, economic and social dimensions, because
factors such as lifespan are of critical importance to obtained performance. Because durability
of buildings is a key consideration in life cycle thinking, validity of the present research is
limited to elaborate alternative building methods as the ones selected.
33
that, the PhD provides guidance for decision-makers on whether or not to change current
systems from a consumer-, policy-maker, or construction-professional viewpoint. It brings
attention to an unexplored, highly relevant research field: sustainable and resilient building for
low-income dwellers in rapidly growing urban centers in Asia, Latin America, and Africa.
5 Future research
Future research demand is stated to deepen the research findings of the specific part of the
Licentiate. In addition, several scientifically relevant fields of activity on the roadmap are
highlighted, which will be looked-at in the course of the PhD.
34
5.1.3 Environmental Impact Assessment
It is worthwhile to reduce data uncertainty for Phases B, C and D in the social housing sector,
with a prominent role for the use phase of houses. Use-phase consumption is likely to rise
with an increase of low-income groups in urban areas and a substantial number of people
transitioning from the lowest to greater-consuming upper-lower or lower-middle income
levels. It is referred to the Chapter Thermal Comfort for more detail on this research demand.
For scale-up scenarios indicating a future change in consumer patterns, in-depth studies on the
effects of biodiversity, scarcity, and land-use changes are recommended. The ongoing decay
of a rich biodiversity in Southeast Asia requires careful consideration of any large-scale
system change [72], [73]. Research has shown that the commonly used indicators in LCA that
address such topics are not sufficiently comprehensive and systematic [74] [76]. Although
improved integration into LCA is becoming a focus in the field (e.g.,[77], [78], the current
shortcomings regarding these aspects and the existence of more elaborate methods outside of
LCA [79], [80] are recognized. The lack of such data is not unique to this paper and has been
acknowledged as a major gap in LCA today [74]. It is suggested to monitor development in
this field and update present LCA once an expert approach is validated and acknowledged.
These indicators become more crucial when the analysed alternative technologies replace
current practices at a relevant scale. We recommend following the cautious principles toward
resource use in large quantities and the guidance of experts in the sector.
35
Philippines, typhoons occur around 20 times per year and earthquakes happen every other
year. Damage assessments after typhoon Haiyan, which had hit the Philippines in November
2013, highlighted that houses using light materials like bamboo had failed the most often. The
PhD targets to show, that the observed failures were directly related to none-engineered
construction methods using the raw material. The PhD will conduct research on building
houses in a typhoon and seismic resilient manner. As performance benchmark was set to
follow the building code requirements while staying in the economic limitations of local
affordability.
buildings with building-integrated technical systems [84]. Through advanced modelling of the
use phase of buildings, it was shown that for more energy-efficient buildings, Phases resource
extraction to construction, gain importance and the use-phase contribution decreases [85].
Nevertheless, for the industrialized building sector it remains the major contributor to the
overall impact. User behaviour of inhabitants at the base of the pyramid, living in naturally
ventilated low-cost houses, has never been systematically assessed nor captured in LCA. It is
Factors for consideration are: (1) Service life of structures; (2) impacts of tropical climate
[81]; (3) variations of user behavior, unrelated to the design of the building envelope;
(4) strongly reduced technical building systems for low-cost houses. Energy use in the tropics
is mostly determined by the cooling load. The latter depends on the building material, design
of the building envelope, surrounding environment, and exposure to heat intake. Small
volumetric houses with metal roofing and without insulation, as analyzed in the PhD, have
substantial heat intake during the day. Higher thermal mass of structures causes higher
nighttime temperatures within them. Construction costs of conventional solutions offer fewer
opportunities for climate-adjusted design of the building envelope. Air conditioning is mostly
unaffordable for the studied low-income settlements, albeit socially attractive. Possibly, the
user behaviour is not influenced by the type of building envelope or indoor comfort, but rather
limited by poverty. The effect of increased indoor comfort has yet to be quantified and
understood in detail, and was therefore omitted in the initial Environmental Impact
Assessment. Since it is deemed a critical component for ecology, society, and economy, the
PhD will cover an assessment of the use-phase energy consumption and thermal comfort in
social housing.
36
and money spent in building local markets as economic indicators; skills and jobs created,
participatory design and customer acceptance test of houses in the society field, and high level
policy advocacy for legal approval and climate change mitigation through green building
interventions for social housing as milestones in the field of governance.
A majority of the product related studies cited above, compared technologies that are already
established on the market [98]. For the PhD, five dimensions of sustainability are named
according to which the raw material potential bamboo is developed and assessed as solution
for the social housing context in the Philippines. In the Licentiate, selected one-dimensional
technical and environmental results were generated. In the course of the PhD, further research
results will be generated and outputs of the implementation project on economic, social and
governance dimension added. The sum of all five dimensions will enable comparing the
alternative building method holistically to current conventional practices.
37
6 Reference
[1] UNEP SBCI, Buildings and climate change: Summary for decision-makers. Paris:
United Nations Environment Programme Sustainable Buildings and Climate Initative,
2009.
[2] UN Habitat, Sustainable housing for sustainable cities: A policy framework for
developing countries. Nairobi: United Nations Human Settlements Programme, 2012.
[3] 1 - Nachhaltiges Bauen -
38
[18] UNEP, Sustainable Building Policies in Developing Countries (SPOD): Promoting
sustainable building and construction practices. Paris: United Nations Environment
Programme, 2011.
[19]
Available: http://www.base-builds.com/. [Accessed: 30-Nov-2015].
[20]
Approach to Incorporating Local Stak
Sustainability, vol. 7, pp. 10922 10960, 2015.
[21]
Sustainability, vol. 5, no. i, pp. 695 710,
2013.
[22]
and top down: Analysis of participatory processes for sustainability indicator
identification as a pathway to community empowerment and sustainable environmental
J. Environ. Manage., vol. 78, pp. 114 127, 2006.
[23] M. Q. Patton, Qualitative Research & Evaluation Methods- Integrating Theory and
Practice, 4th ed. London: SAGE, 2015.
[24] g, sorting and sifting of qualitative data analysis: debates and
Qual. Quant., pp. 1135 1143, 2014.
[25]
Ecol. Indic., vol. 11, no. 5, pp. 1385 1395, 2011.
[26] -
stakeholder contexts: applicability of life cycle thinking in development planning and
J. Clean. Prod., vol. 17, pp. 67 76, 2009.
[27]
-
Nov-2015].
[28] -income
J. Bamboo Ratt., vol. 2, no. 4, pp. 381 396, 2003.
[29] - Bamboo - Structural
[30] - 1 Bamboo -
Determination of physical and mechanical properties -
[31] - 2 Bamboo -
Determination of physical and mechanical properties -
53, p. 160, 1989.
[32] Eurocode 5: EN 1995-1- -1-1:2004 Eurocode 5: Design of timber
structures- Part 1-1: General -
[33]
Available: https://www.fprdi.dost.gov.ph/. [Accessed: 26-Nov-2015].
[34] -2008: Testing method of fire resistance for structural components in
39
[35] -1 Fire-resistance tests-
Elements of building construction-
[36] - Method of fire resistance test for
[37]
[Online]. Available: http://puskim.pu.go.id/, Retrieved 20.09.2015. [Accessed: 20-Nov-
2015].
[38] UN Habitat, Green Building Interventions for Social Housing, vol. XXXIII. Nairobi:
United Nations Human Settlements Programme, 2014.
[39] M. a J. Huijbregts, S. Hellweg, R. Frischknecht, H. W. M. Hendriks, K. Hungehbühler,
[44] J. P. Rojo and C. A. Roxas, Philippine Erect Bamboos- a field identification guide.
Forest Products Research and Development Institute, 2000.
[45] Recommends
Series, no. No 53-A, Los Banos, Laguna, p. 74, 1991.
[46] -mechanical properties and anatomical
Philipp. Lumberm., vol. 32, no. 4
& 5, pp. 25 27, 35, 32 36, 1986.
[47] ASTM D143-14, Standard Test Methods for Small Clear Specimens of Timber 1.
American Society for Testing and Materials, 2014.
[48] n of Philippine
40
[53]
Holz als Roh- und Werkst., 1980.
[54] I. Zaragoza- -mechanical properties of a Mexican
Maderas Cienc. y Tecnol., vol. 17, no. 3, pp. 505 516, 2015.
[55]
manage Waste Manag., vol. 32, no. 3,
pp. 532 41, 2012.
[56]
End-of- J. Ind.
Ecol., vol. 17, no. 3, pp. 396 406, 2013.
[57] ASEP, National Structural Code of the Philippines, Volume 1- Buildings, Towers and
Other Vertical Structures, 6th ed. Quezon City: Association of Structural Engineers of
the Philippines, 2010.
[58] G. M Madera y
Bosques, vol. 20, pp. 111 125, 2014.
[59]
Allowable Stresses for Bamboo Guadua Angustifolia Kunth
76 80, 2012.
[60] International Network for Bamboo and Rattan, The Climate Challenge and Bamboo:
Mitigation and an, International Network for Bamboo andAdaptation, vol. 86. 2011.
[61] P. Pawelzik, M. Carus, J. Hotchkiss, R. Narayan, S. Selke, M. Wellisch, M. Weiss, B.
-
based materials - Resour.
Conserv. Recycl., vol. 73, pp. 211 228, 2013.
[62]
of climate impacts due to biogenic carbon storage across a range of bio-product
Environ. Impact Assess. Rev., vol. 43, pp. 21 30, 2013.
[63] S. V. Jørgensen, F.
surface albedo and biodiversity impacts from establishment of a miscanthus
J. Environ. Manage., vol. 146, pp. 346 354, 2014.
[64] A. Levasseur, P. Lesage, M. Margni, and R. Samson,
J. Ind. Ecol.,
vol. 17, no. 1, pp. 117 128, 2013.
[65] - Int. J.
Life Cycle Assess., vol. 9, no. 5, pp. 339 341, 2004.
[66] EC JRC - IES,
Specific guide for Life Cycle Inventory data sets. EUR 24709 EN. 2010.
[67] A, a proposal
41
3, 2010.
[69] -Environmental
Management,
[70]
[71]
building sector: analytical tools, environmen Int. J. Life
Cycle Assess., no. Section 2, 2015.
[72]
Biodivers. Conserv., vol. 19, pp. 955 972, 2010.
[73] N. S. Sodhi, M. R
Biodivers. Conserv., vol. 19,
pp. 317 328, 2010.
[74] M. Finkbeiner, R. Ackermann, V. Bach, M. Berger, G. Brankatschk, Y.-J. Chang, M.
Grinberg, A. Lehmann, J. Martínez-Blanco, N. Minkov, S. Neugebauer, R. Scheumann,
[81]
Renew. Sustain. Energy Rev., vol. 45, pp. 244 248, 2015.
[82] O. Ortiz, F. Castells, and G.
Constr. Build. Mater., vol. 23, no. 1,
pp. 28 39, 2009.
[83] -Cycle Assessment
Applications J. Archit. Eng., vol. 17, no. March, pp. 15 23,
42
2011.
[84]
(LCA) and life cycle energy analysis (LCEA) of buildings and the building sector: A
Renew. Sustain. Energy Rev., vol. 29, pp. 394 416, 2014.
[85]
WSB14, vol. 13786, pp. 9 16,
2014.
[86] G. a. Men -criteria decision analysis in natural resource
For. Ecol.
Manage., vol. 230, pp. 1 22, 2006.
[87] L. Turcksin, C. Macharis, K. Lebeau, F. Boureima, J. Van Mierlo, S. Bram, J. De
Ruyck, L. Mertens, J.- -actor multi-
criteria framework to assess the stakeholder support for different biofuel options: The
Energy Policy, vol. 39, no. 1, pp. 200 214, 2011.
[88] -user sustainability assessment of
Environ. Impact Assess. Rev., vol. 32, no. 1, pp. 170 180, 2012.
[89] ort in
flanders: Multi-actor multi- Sustain., vol.
5, pp. 4222 4246, 2013.
[90] J.-J. Wang, Y.-Y. Jing, C.-F. Zhang, and J.- -criteria decision
analysis aid in sustainable energy decision- Renew. Sustain. Energy Rev., vol.
13, pp. 2263 2278, 2009.
[91]
Renewable Energy: An Overview of the Application of Multiple Criteria Decision
Making Techniques Sustainability, vol. 7, no. 10, pp. 13947 13984,
2015.
[92]
J. Oper. Res. Soc., vol.
61, no. 9, pp. 1328 1339, 2009.
[93] -making
techniques and applications Expert Syst.
Appl., vol. 42, no. 8, pp. 4126 4148, 2015.
[94] P. O. Akadiri, P. O -criteria evaluation model
Autom. Constr., vol. 30,
pp. 113 125, 2013.
[95] W. Contreras-miranda, V. Cloquell- nicas de
decisión multicriterio en la selección de componentes estructurales , a partir de la
tecnología de la madera , para construcción de viviendas sociales en Venezuela
16,
no. 3, pp. 7 22, 2010.
[96]
Omega, vol. 41, no. 2,
pp. 270 279, 2013.
43
[97] M. Medineckiene, E. K. Zavadska -criteria decision-
Arch. Civ. Mech.
Eng., vol. 15, no. 1, pp. 11 18, 2015.
[98] L. Tupenaite, E. K. Zavadskas, A. Kaklauskas
J. Civ.
Eng. Manag., vol. 16, no. 2, pp. 257 266, 2010.
[99] is
Decis. Support
Syst., vol. 54, no. 1, pp. 610 620, 2012.
44
7 Annex
The Annex contains all papers in the order specified in the List of Publications.
45