building systems in malaysia - connecting repositories · 2016-08-03 · improving ecological...

Construction Management a n d Economics, 20 14 Vol. 32, Nos. 1-2, 183-195, http://dx.doi.org/l0.1080/01446193.2013.825373

Improving ecological performance of industrialized building systems in Malaysia

RIDUAN YUNUS'" and JAY YANG~

' ~ a c u l t ~ of Civil and Environmental Engineering, Universiti Tun Hussein Onn Malaysia, Batu Pahat, Malaysia 2~epartment of Civil Engineering and Built Environment, Queensland University of Technology, Brisbane, Australia

Received 12 December 2012; accepted 28 June 2013

For construction stakeholders to fully embrace sustainability, its long-term benefits and associated risks need to be identified through holistic approaches. Consensus among key stalzeholders is very important to the improvement of the ecological performance of industrialized building systems (IBS), a building construction method gaining momentum in Malaysia. A questionnaire survey examines the relative significance of 16 potentially important sustainability factors for IBS applications. To present possible solutions, semi-structured interviews solicit views from experienced IBS practitioners, representing the professions involved. Three most critical factors agreed by key stakeholders are material consumption, waste generation and waste disposal. Using SWOT analysis, the positive and negative aspects of these factors are investigated, with action plans formulated for IBS design practitioners. The SWOT analysis based guidelines have the potential to become part of IBS design briefing documents against which sustainability solutions are contemplated, selected and implemented. Existing laowledge on ecological performance issues is extended by considering the unique characteristics of IBS and identifying not only the benefits, but also the potential risks and challenges of pursuing sustainability. This is largely missing in previous research efforts. Findings to date focus on providing much-needed assistance to IBS designers, who are at the forefront of decision-making with a significant level of project influence. Ongoing work will be directed towards other project development phases and consider the inherent linkage between design decisions and subsequent sustainability deliverables in the project life cycle.

IZeywords: Industrialized Building System, decision support, ecological, Malaysia, sustainability.

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Introduction

Industrialized building systems (IBS), also l aown as prefabrication, employ a combination of ready-made components in the construction of buildings. IBS applications can improve the quality of production, simplify construction processes and minimize waste generation (Construction Industry Development Board Malaysia, 2005; Blismas et al., 2006; Shen et al., 2009). T h e unique characteristics of the IBS method, such as offsite production and standardization of components and design using modular coordination, have great potential to enhance construction sustainability (Jaillon and Poon, 2008; Hamid and Icamar, 2012). I t will also help improve work

productivity, which has been a longstanding concern in the building industry. T h e Malaysian government is urging the building industry to shift from traditional practices to IBS-based construction. Charting the future directions of local industry, the Construction Industry Master Plan (CIMP) of Malaysia specifically highlights government strategies for IBS implementation (Construction Industry Development Board Malaysia, 2006). T o assess IBS-related issues at the project level, the IBS Centre was set u p in January 2007.

Despite top-level advocacy, the take-up rate of IBS in the Malaysian construction industry is still low compared to developed countries such as the United IGngdom, Germany, the United States of America

*Author for correspondence. E-mail: [email protected]

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Yunus and Yang

and Japan. Previous literature reported the percent- ages of IBS usage in Malaysia at only 10-15% of the overall volume of work during 2003 and 2006, while other countries are easily double that (Hamid et al., 2008; I<amar et al., 2009; Nawi et al., 2011). Polat (2010) observed that the level of IBS implementation is very low in developing countries because of the technological dependency. Moreover, the majority of key stakeholders in Malaysia may have limited understanding and perhaps misconceptions on the potential of IBS. They are often poorly informed on IBS design, unable to foresee its benefits and unaware of its relevance to sustainability (Yunus and Yang, 2012). Current IBS practices also exhibit an apparent lack of focus and linking to sustainability. This needs to be rectified to achieve the full potential of IBS.

Sustainability considerations have expanded the concerns of people in the construction industry by setting a higher expectation in delivering building and infrastructure projects. An integrated approach with a broader perspective is vital to encourage cooperation of the lzey stalzeholders in delivering a building with limited resource consumption, carbon reduction and biodiversity targets in mind (Yang, 20 12). Moreover, environmental concerns are best addressed on a community scale which involves industry players at the project level (Cole, 2011). Sustainability initiatives also require early collaboration among stalzeholders (Horman et al., 2006; Yang and Lim, 2008; Jaillon and Poon, 2010). Therefore, a consensus among lzey stakeholders in setting the mutual prospective and agreeable targets of sustainability prior to schematic design, is crucial for sustainable IBS delivery.

Cole (2004) stated that conventional methods of evaluating environmental performance need to adopt new approaches that employ a broader range of considerations, while being respectful of simplicity and practicality to malze them more widely accessible. Decision tools that are capable of encapsulating sustainability principles, including environmental performance in the IBS design stage, will help optimize building components and ensure they perform the intended functions. Luo et al. (2006) highlighted that inconsistent, inappropriate and wrong decisions will affect the performance of IBS buildings. Effective decision-malung is mandatory in eliminating construction problems such as change orders, delays in production or construction and budget overrun, during IBS implementation (Chen et al., 20 10a).

In light of the findings of an ongoing study aimed at formulating decision-making guidelines that promote the ecological performance of IBS applications, critical factors relating to sustainable construction and operation of IBS building products are explored. Using feedback from experienced practitioners in

local industry, current industry concerns and critical issues have been identified. Questionnaire surveys focus on the exploration of potential factors affecting IBS ecological performance during the design phase of a project. Interview surveys and subsequent statistical analysis established a consensus between key stakeholders regarding their views on making effective design decisions. A decision-malung strategy is then formulated using SWOT (strengths, wealz- nesses, opportunities and threats) analysis for the identified factors and issues.

Literature review

Sustainable development is becoming an essential part of human activity in terms of providing quality of life while preserving resources for future generations. The level of sustainability integration in built environment activities is increasing because of rapid expansion in information, technology and product development (Jaafar et al., 2007; Yang, 2012). The construction industry requires holistic decision-making and innova- tive solutions to enhance sustainability while realizing mutually beneficial outcomes for all stakeholders. With the support of information technology (IT), integration strategies and approaches will help over- come industry fragmentation. However, the absence of a common language and consensus among stakeholders is preventing full consideration of sustainability, especially from environmental perspectives.

IGbert (2008) highlighted the seven principles of sustainable construction as (I) reduce consumption of resources (reduce); (2) reuse resources (reuse); (3) use recyclable resources (recycle); (4) protect nature (nature); (5) eliminate toxics (toxics); (6) apply life cycle costing (economics); and (7) focus on quality (quality). These principles are provided as a benchmark for creating a better world for future generations.

Ecological performance is the promotion of any attributes that will increase the ability of IBS construction to preserve natural resources and reduce negative impacts on the environment. It is necessary to ensure environment sustainability (Figge and Hahn, 2004; Jaillon and Poon, 2008). For example, improvements in IBS component quality will help ensure consistent standards of insulation and reduce operational energy. Moreover, IBS offers major benefits in the environmental sphere, such as material conservation and reductions in waste and air pollution. This has been proven by several researchers such as Jaillon et al. (2009), Baldwin et al. (2009) and Tam et al. (2007a). Many IBS components are locally manufactured using local products in reusable

Table 1 Potential of ecological performance factors in IBS Table 1 (Continued)

applications No. Sustainability factors Source

No. Sustainability factors Source

1 Waste generation Burgan and Sansom (2006) Richard (2006) Jaillon and Poon (2008) Chen et al. (2010a) Teo and Loosemore (2003) Tam et al. (2007b) Arif and Egbu (20 10)

2 Ecology preservation Adetunji et al. (2003) Al-Yami and Price (2006) Burgan and Sansom (2006) Shen et al. (2007) Soetanto et al. (2004)

3 Energy consumption in Holton (2006) design and construction Abidin and Pasquire (2005)

Nelms et al. (2007) Shen et al. (2007) Burgan and Sansom (2006) International Council for Building Research and Innovation (1 999) Chen et al. (2010a)

4 Embodied energy Department of Trade and Industry (200 1)

0 .- V) 5 Waste disposal C 0 + .a 3 a 6 Health of occupants 8 A (indoor air quality) m r: 0 CJ 3 7 Material consumption s! h e

B 8 Recyclable/renewable

contents 9 Site disruption

10 Transportation and lifting

Holton (2006) Tam et al. (2007a) Soetanto et al. (2004) Al-Yami and Price (2006) Gibberd (2008) Chen et al. (2010a) Chen et al. (2010a) Gibberd (2008) Holton (2006) Luo et al. (2005) Nelms et al. (2007) Taher et al. (2009) Jaillon and Poon (2008) Chen et al. (2010a)

Burgan and Sansom (2006) Chen et al. (2010a) Gibb and Isaclz (2003) Gorgolewski (2005) Blismas and Wakefield (2009) Department of Trade and Industry (2001) Luo et al. (2006) Patzlaff et al. (2010) Yee (2001) Zhao and Riffat (2007) Song et al. (2005) Gorgolewslzi (2005)

11 Land use Adetunji et al. (2003) Al-Yami and Price (2006) Burgan and Sansom (2006) International Council for Building Research and Innovation (1 999) Shen et al. (2007)

12 Reusable/recyclable Song et al. (2005) elements

13 Operational energy Department of Trade and Industry (2001) Chen et al. (2010a)

14 Water consumption Adetunji et al. (2003) Al-Yami and Price (2006) Gibberd (2008) Holton (2006) Nelms et al. (2007) Chen et al. (2010a)

15 Environment Adetunji et al. (2003) administration

16 Pollution generation Shen et al. (2007) Shen et al. (2010) Chen et al. (2010a)

mouldings or assembly lines. This significantly reduces transportation costs and traffic congestion. Moreover, construction waste can be minimized and waste from offcuts is immediately recycled. By understanding the IBS potential in placing the environment as a priority, designers and consultants will be able to explore issues of significance to ecological degrada- tion. Table 1 lists a total of 16 ecological performance factors in IBS applications which have been identified from the literature review.

Research gap

Most of the current IBS implementation isolates the design and construction processes (Nawi e t al., 201 1). The implementation is often design-oriented, cost- focused and project-delivered without specific consideration of maximizing the advantages IBS brings. The conventional approach in IBS applications can also hinder cooperation among liey stalieholders (Hamid and Icamar, 201 2; Nadim and Goulding, 20 11; Nawi et al., 201 1). There is a lack of communication and cooperation among the key stakeholders known as 'over the wall' syndrome (Evbuomwan and Anumba, 199 8). In these conventional approaches, manufacturers and contractors can only become involved after

(Continued) - - -

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the design stage. The lack of integration will result in problems for the supply chains such as delays, under- or over-supply and constructability issues. The need for subsequent re-design and re-planning will increase project costs (Hamid et al., 2008). It is important to allow each stakeholder to define issues and set sustainability goals prior to schematic design and then continue through construction, operation and demolition of the building.

I n addition, little attention has been given to improving sustainability in the early stage of construction, especially when the designer prepares the draw- ings and specifications (Ding, 2008). Contrary to the IBS implementation approaches, most of the available assessment guidelines and tools are not design- oriented. They were constructed to endorse or disapprove a final design therefore cannot serve the purpose for designers to contemplate alternatives (Soebarto and Williamson, 200 1). In Indonesia for example, professional designers and contractors are engaged in separate contracts, which means the contractors only get involved after the designs are completed (Trigunarsyah, 2004). This engagement style leads to isolation and ignores opportunities in optimizing project benefits such as cost savings and speedy completion. Therefore, early involvement and cooperation among stakeholders is also very important to improve sustainable IBS construction.

Environmental issues and financial considerations should be evaluated together in improving sustainability. Some assessment tools, such as the Building Research Establishment Environmental Assessment Method (BREEAM) and Leadership in Energy and Environmental Design (LEED), do not include financial aspects in the evaluation framework (Ding, 2008). The other tools such as Green Star, Green Mark, and Green Building Index also focus on the evaluation of design against a set of environmental criteria such as energy and water efficiency, indoor environmental quality and sustainable site management. The considerations on the financial aspects are neglected and may lead to a project that, while envi- ronmentally sound, would be very expensive to build. The challenge for the construction industry is to deli- ver economic buildings that maintain or enhance the quality of life, while at the same time reducing the impact of the social, economic and environmental burdens from the community.

Currently, the IBS Score System, which was developed by the Construction Industry Development Board (CIDB) of Malaysia, is used to measure the usage of IBS. This tool measures the percentage of IBS usage in a consistent way with a systematic and structured assessment system (Construction Industry Development Board Malaysia, 2005). In Malaysia,

the current assumption is that higher IBS scores mean more 'sustainable construction'. In a way, a higher score can indeed reflect a reduction of site labour, an improvement in quality, neater and safer construction sites, faster project completion as well as lower total construction cost (Construction Industry Develop- ment Board Malaysia, 2005). However, it does not explicitly and directly represent sustainability attributes (e.g. environment, social and economy) for IBS applications. The assessment scheme focuses on the percentage of IBS components used in construction, such as precast concrete, component repeatability and design using modular coordination concepts.

Elsewhere, researchers considered IBS in assessment tools such as PPMOF (Prefabrication, Preas- sembly, Modularization and Offsite Fabrication), IMMPREST (Interactive Method for Measuring PRE-assembly and Standardization), PSSM (Prefabri- cation Strategy Selection Method) and CMSM (Construction Method Selection Model). PPMOF was a computerized tool developed to assist industry practitioners in evaluating the applicability of IBS components on their projects (Song et al., 2005). It focused solely on strategic level analysis. Chen et a2. (2010b) stated that decisions might be biased because the weight assigned to each category is subjective. IMMPREST, which was developed in the United IGngdom, attempted to include sustainability elements for decision-making (Pasquire et al., 2005). However, it has several shortcomings in comprehensively evaluating sustainability (Luo et al., 2006). The most significant challenge in using this tool is the lac$ of information at the early stage of a project (Chen et al., 20 lob). For successful early collaboration between the design and construction teams, sufficient information is required to facilitate better understanding and minimize misconception among teams. In the United States, PSSM was developed to help a project team find a suitable prefabrication strategy for a building system. The solution was formulated through understanding the synergies and issues with IBS strategies, building processes and building performance early in the design phase, but it only focused on cur- tain wall systems, mechanical systems and wall frames (Luo et al., 2006). The latest tool, CMSM was specifically designed for concrete building projects to select and optimize IBS components (Chen et al., 2010b).

While these existing tools provide sound bench- marlzs in the selection of IBS, they are not able to make effective recommendations on how to improve sustainability based on the chosen options. As highlighted by Ofori and IGen (2004), the absence of relevant information to guide designers hinders the incorporation of sustainability into holistic IBS designs and delivery. This is the crux of the issue in

Ecological performance

the application of IBS in Malaysia. It is important to provide design professionals with appropriate guidance at the project level.

Blismas et al. (2006) stated that most of the decision tools for assessing IBS applications focus on economic issues. They often disregard 'softer' issues which are perceived as insignificant, such as life cycle prediction, health and safety and the effects on energy consumption. There is a need to establish holistic methods of IBS selection by considering triple bottom line (TBL) criteria and responding to institutional implications in order to improve overall IBS implementation. As discussed in the previous section, IBS applications tend to be linked with government projects primarily. As such, political scenarios and government support are very important aspects. This research explores the environmental, economic and social aspects of IBS and extends sustainability assessment to include 'technical quality' and 'implementation and enforcement' aspects. However, the focus is on ecological performance in enhancing sustainability for IBS applications.

Developing and developed countries may have different priorities in terms of IBS applications in terms of the type of IBS, characteristics of local communi- ties and available resources. IBS in Malaysia also con- sists of structural applications, such as timber and steel, which exhibit unique characteristics for the improvement of sustainable deliverables (Burgan and Sansom, 2006). Most of the tools presented to date only reflect scenarios of developed countries. Local and regional characteristics and the physical environment are among the important elements to be considered when measuring the level of sustainability. With the flexibility for adaptation, issues studied in developed countries are unlikely to be applicable or even relevant to developing countries (Cohen, 2006).

Therefore, there is a need to identify critical issues and provide solutions to local problems. Exploration of the benefits, potential risks and challenges of pursuing sustainability can lead to a holistic view in decision-making. With unified views and agreements between key stakeholders, a consensus in encapsulating sustainability strategies can be achieved.

Research approach

Creswell (2009) named four different views of research paradigms as 'postpositivist', 'social con- structivist', 'advocacy and participatory' and 'prag- matic' worldviews. Each view represents the cluster of beliefs and perspectives a researcher should hold within a scientific discipline (Bryman, 1992). This research is oriented towards solving practical industry

problems and concerns on local sustainability development. The most applicable philosophical position and orientation towards the inquiry for this research is pragmatism. The focus of this approach is not the theory, but the research problems. The solution can be established by deriving knowledge regarding the problem, which arises from actions, situations, and consequences. Pragmatism often demands mixed methods to solve research problems (Creswell, 2009). Several research mechanisms are integrated to ensure the success of this project, including questionnaire surveys, semi-structured interviews, SWOT analysis and the development of decision-making guidelines.

The unit of analysis refers to the type of unit a researcher uses when measuring and the aggregation level of data during subsequent analysis (Neuman, 2007). The common units of analysis are the individual, the group (e.g. family, friendship group), the organization (e.g. corporation, company), the social category (social class, gender, race), the social institution (e.g. religion, education) and the society (e.g. nation, a tribe). In this study, the unit of analysis used is the organization. Data were collected from different organizations such as contractors, designers and manufacturers. These data were analysed by comparison and synthesis to extract findings and facilitate discussion on the subjects investigated.

From the literature review of existing decision- making tools, 16 potentials factors have been identified as capable of improving the ecological performance in IBS applications (Table 1). These factors were included in a questionnaire survey instrument that was piloted before the main survey investigation. It is important to compile survey questions into use- able formats in describing responses, comprehensive- ness and acceptability of the questionnaire (Fellows and Liu, 2008). At first, the questionnaire is used to identify critical factors in IBS applications that are able to improve sustainability from environmental dimensions. A consensus among key stakeholders is achieved by statistically analysing the interrelation- ships between the investigated factors. Later, semi- structured interviews were used to gather information regarding agreeable strategies and practical solutions.

SWOT (strengths, weaknesses, opportunities, and threats) analysis was employed in this research. SWOT can evaluate the internal and external conditions simultaneously by recording all of the possibilities and opportunities. As a result, through a systematic approach, support for a decisive situation can be achieved (Srivastava et al., 2005). This analysis has an advantage in that it presents holistic, rather than 'preferred', views regarding sustainable delivera- b l e ~ for IBS application. It also can provide a good basis for the formulation of implementation strategies.

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During the questionnaire survey, a total of 300 questionnaires were distributed to potential respondents randomly selected using CIDB databases and other listings of Malaysian construction industry organizations. To ensure a maximum level of response rate, a combination of hard copy mail out, online survey, and face-to-face consultation was employed. As a result, 115 valid questionnaires were received and used in the analysis, representing a response rate of 38%. In the questionnaire, the respondents were asked to assign an appropriate rating on a five-point scale where 1 is 'very insignificant', 2 is 'insignificant', 3 is 'neutral', 4 is 'significant', and 5 is 'very significant'. The formula used to calculate the mean score rating is:

Mean = l(n1) +2(nz) +3(n3) +4(n4) + 5(n5) (nl + n2 + n3 + n4 + n5)

j

A t-test was used to identify the most significant factors among those selected. This method was previ- ously proven by several researchers such as Elzanayake and Ofori (2004) and Wong and Li (2006) in related studies. In this research, the null hypothesis (factors were neutral, insignificant, and very insignificant) is accepted if the t-value is smaller than 1.6583 (the critical t-value) .

It is also important to consider the differing views between each organization type regarding the factors significant to improving the IBS ecological performance. Non-parametric testing was applied in this study because the variables were measured by ordinal scale and not in normal distribution. In order to assess how different types of organizations rate these factors, the Icruskal-Wallis one-way analysis of variance (ANOVA) proves to be the most appropriate for the problem on hand (Wong and Li, 2006) therefore was used. The chi-square (X2) was interpreted as Icruskal-Wallis value representing the rating of sustainability factors across respondents' organizations. When the p-value is lower than 0.05, there will be significant differences between views of organizations.

In the interview study, 20 interviewees from different types of organizations participated. They were identified through CIDB recommendation based on their previous worlz, as well as from the questionnaire study. All interviewees have more than 10 years of experience in the Malaysian construction industry. The variety in the respondents' backgrounds allows the authors to identify different professional perceptions in pursuing sustainability.

Flexibility in the semi-structured interviews allowed the researchers to comprehensively investigate and explore detailed information on each issue, while at

the same time maintaining focus on the research objectives. Subsequently, SWOT analysis was used to provide decision-malting guidelines. The data from the semi-structured interviews were organized and transcribed before the data were keyed into QSR NVivo version 9. The strengths, weaknesses, opportunities, threats and potential action plans were explored and interpreted from the available coding. The interpretation process provided themes and descriptions in formulating the SWOT based decision-malung frameworks and guidelines.

Designers require lots of information to guide them in making appropriate decisions, especially when inte- grating sustainability efforts (Ofori and Ken, 2004). In project management, SWOT analysis is able to help a decision-maker decide what risks they need to talte in order to see the expected return on investment (Milosevic, 2010). Lu et al. (2009) adopted SWOT analysis as the basic methodology to gain insight into the internationalization of China's construction companies in the global market. In Vietnam, Luu et al. (2008) proposed a framework that integrates the balanced scorecard and a SWOT matrix to measure the performance of construction firms in developing countries. SWOT analysis is ideal for analysing the situation each investigated factor presents. The interrelated criteria also help to develop potential strategies. Through such analysis, decision-makers can exploit new opportunities by utilizing available strengths, avoiding weaknesses and diagnosing any possible threats in the examined issues. SWOT analysis can present a framework capable of integrat- ing potential sustainability factors into the equation while not being inflexible and restrictive. It will be able to loosely bind issues together and provide adequate information within the context of the subject matter for decision-malting assistance. The outcomes will then act as 'guidance' documents for the designers to consider and contemplate sustainable solutions in IBS applications. Any other type of framework will not suit the context of the examined problems.

Further research worlz in this ongoing study will utilize several case studies to assess the appropriate- ness and level of efficiency of the developed decision tools.

Results and analysis

Sampling is important in this study because it is rarely possible to examine an entire population, which is largely due to the resource restriction in most studies. The objective of sampling is to provide a practical means of enabling data collection and processing


components of research to be conducted while -ensuring that the sample provides a good representation of the population (Fellows and Liu, 2008). Based on the nature of the research, cluster sampling was adopted to investigate different perceptions from various groups of respondents.

Seven groups of respondents were identified as the lzey stakeholders in IBS application based on their organization type. The organization types were design/consultancy, contractors, manufacturing, user or facility management, property development/client, researchiacademic institution and government author- itylagency. Using official professional listings (for example, from the Construction and Industry Devel- opment Board, Industrialized Building System Cen- tre, Green Building Index Malaysia) as a basis, the respondents' backgrounds were reviewed to assess their suitability for participating in the survey. This type of sampling is called 'purposive or judgmental sampling' (Neuman, 2007). It is used to select participants from the specialized population: in this case, those with experience and knowledge in IBS implementation. Abidin and Pasquire (2005) also adopt this strategy to select particular settings, persons or events to study sustainability value chain problems.

The questionnaire consisted of four major parts. Part 1 captured the respondents' demographic details such as their level of experience and background. Part 2 examined the level of significance of potential factors in enhancing sustainability deliverables for IBS construction. Part 3 investigated the impact of those potential sustainability factors in providing a better future without neglecting present needs. In Part 4,

the respondents were asked to give additional com- ments or suggestions. Finally, the respondents were invited to participate in the subsequent investigation phase of this research.

Analysis of the survey response data produced mean significance values for the 16 ecological performance factors ranging from 3.78 to 4.50. Table 2 shows that 10 factors scored mean values greater than 4.0 and the remaining six factors scored between 3.78 and 3.99. The standard deviations for this analysis show very good data accuracy as little variation exists from the mean evaluated. Subsequently, a t-test was used to help the authors to identify the most significant factors. Three factors are therefore identified as the most significant in improving sustainability in the ecology performance dimension. They are waste generation, waste disposal and material consumption.

The Ieuskal-Wallis one-way analysis of variance (ANOVA) reveals that there was no significant differ- ence between various stakeholders for waste generation (p value 0.215) and waste disposal (p value 0.215). However, material consumption (p value 0.005) shows slight differences across key stakeholders. A possible reason for this may be that manufacturers and users are typically involved only with the end product. Unlike other groups, they are not certain about esti- mating material consumption, especially during the construction stages.

Waste generation was ranlzed first in the survey analysis (Table 2: mean value 4.50). Burgan and Sansom (2006) highlighted that since IBS employs offsite manufacturing processes, it has the potential to minimize waste through the entire building life cycle.

Table 2 Ranking sustainability factors categorized in the ecological performance criteria

Sustainability factors Rank Mean Std. deviation t-value

1 Waste generation 1 4.50 0.792 6.652 2 Waste disposal 2 4.38 0.838 4.828 3 Material consumption 3 4.28 0.785 3.837 5 Recyclable/renewable contents 4 4.12 0.974 1.352 5 Site disruption 5 4.10 0.868 1.181 6 Transportation and lifting 6 4.08 1.036 0.810 7 Reusablelrecyclable elements 6 4.08 1.010 0.838 8 Ecology preservation 8 4.04 0.976 0.482 9 Water consumption 9 4.01 1.031 0.091 10 Embodied energy 9 4.01 0.940 0.100 11 Environment administration 11 3.99 0.911 -0.103 12 Pollution generation 12 3.96 0.972 -0.387 13 Health of occupants (indoor air quality) 13 3.92 0.992 -0.853 14 Operational energy 14 3.83 1.051 -1.700 15 Energy consumption in design and construction 15 3.80 0.888 -2.437 16 Land use 16 3.78 0.884 -2.661

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Table 3 SWOT analysis results on ecological performance criteria

Sustainability factor Strengths Weaknesses Opportunities Threats

Material IBS produce minimum Efforts to sort different types of Usage of renewable materials can improve Waste minimization decision should consumption waste (Sl) wastage are required (Wl) recovery rates (01) be agreed during the design stage

(TI) Able to facilitate Need to design proper location Less virgin materials are used when Proper planning and checklist are separation of waste for waste collection (W2) construction waste is recycled for another required (T2) streams (S2) project (02) Easy to separate Lack of cooperation from disposal to different subcontractor (W3) types (S3) Potential to be reused (S4)

Waste generation No waste (Sl) Ineffective planning causes mass Reduce wrapping for elements Require proper handling (Tl) wastages (Wl) delivered on site (01)

Less debris (S2) Required precise dimension and Prevent waste by proper Damage during transportation and measurement for each element maintenance (02) (W2)

handling (T2)

Exact elements are delivered to site (S3)

Design with whole life cycle in mind to Unfit problem (T3) minimize waste (03) Specify and use reclaimed or waste materials in construction (04) Recycled waste (05)

Waste disposal IBS produce minimum Efforts to sort different types of Usage of renewable materials can Waste minimization decision should waste (Sl) wastage are required (Wl) improve recovery rates (01) be agreed during the design stage

0-1) Able to facilitate Need to design proper location Less virgin materials are used when Proper planning and checklist are separation of waste for waste collection (W2) construction waste is recycled for required (T2) streams (S2) another project (02) Easy to separate Lack of cooperation from disposal to different subcontractor (W3) types (S3) Potential to be reused (S4)


Jaillon et al. (2009) identified waste reduction as one of the major benefits when using IBS compared with conventional construction. Their analysis shows the average wastage reduction level was approximately 52%. Therefore it is extremely important to minimize the source of waste generation through IBS design and construction and, at the same time, alleviate the burden of waste management.

Waste disposal is ranked as the second most important factor (Table 2: mean value 4.38). The IBS manufacturing process allows for better management of the waste stream (Gorgolewslu, 2004, 2005). Many offsite manufacturing plants have recycling facilities and the integration of industrial ecological systems allows waste from one production process to become a resource for the next. In addition, effective design will ensure that resources are consumed efficiently and materials ordered strictly to standard sizes, thus minimizing onsite processing and offcuts. Soetanto et al. (2004) stated that the disposal (i.e. demolition and site clearance) costs can be minimized when adopting IBS applications.

The third most significant factor for ecological performance is material consumption (Table 2: mean value 4.28). In Malaysia, the expansion of urban and industrial areas has caused mineral resource sterilization through the encroachment upon existing mines and quarries, therefore preventing exploitation of and access to new and undeveloped mineral resources (Hezri and Hasan, 2006). Jaillon and Poon (201 0) stated that replacing conventional construction with IBS applications will help reduce material consumption. Similar findings also highlighted by Tam et al. (2005) confirmed that material consumption can be significantly reduced through IBS construction. In their study, savings achieved from plastering and timber formwork alone counts to approximately 100% and 74-87% respectively.

The three most significant factors were further investigated through semi-structured interviews. Interviews allow the authors to explore details of each factor in depth and to identify solutions or action plans to consider, encapsulate and improve sustainability in IBS applications. In this investigation, SWOT (strengths, wealwesses, opportunities, and threats) analysis is used to present information and encapsulate recommendations into a practical tool.

Twenty respondents participated in the interview sessions. These respondents belonged to seven types of organizations, namely designer/consultant companies, manufacturer companies, contractor companies, user or facility management companies, clientldevel- oper companies, researcWacademic institutions and authority/government agencies. With a minimum of 10 years of experience in real-world IBS applications,

they are considered the most laowledgeable and authoritative to provide recommendations in enhancing sustainable deliverables. Table 3 presents the SWOT analysis results on ecological performance criteria.

The internal and external conditions are evaluated simultaneously by recording all of the possibilities and opportunities. In this research, group-wise analysis was used in SWOT analysis. This methodology was effective in providing factors and major objectives and to clarify unclear issues by developing a consensus among stalzeholders (Srivastava et al., 2005). As shown in Table 3, the significant strengths for material consumption were IBS produce minimum waste (Sl), able to facilitate separation of waste streams (S2), easy to separate disposal to different types (S3) and potential to be reused (S4). These strengths were then linlzed with the recommendation suggested in the semi-structured interviews. For example, S1 provides an idea for stalzeholders to adopt methods and technology with less demand on materials for their project as one of the action plans. 3R (reduce, reuse and recycle) strategies can be a way forward to achieve sustainable development in Malaysia (Hamid and ICamar, 20 12). Similar analysis was applied to both positive and negative considerations of all critical factors. Table 4

Table 4 Recommendations in improving sustainability in IBS implementation

Sustainability factors Recommendations: action plans

Material Promote recycle materials and consumption resources

Use local resources and materials Examine the nature of the materials used Regulation to use sustainable resources Effective and optimum materials handling Follow specification provided Adopt less materials technology

Waste generation Precision in size and dimension Proper handling Higher penalty and tax levies Design for environmental impact Plan efficiently

Waste disposal Stringent environmental regulations Disposal management and requirements Recycle and reuse approach Team up with other builders to recycle

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shows the recommendations based on the complete analysis. The recommendations provide step-to step actions for stakeholders at the project level for specific sustainability challenges.

Discussion

Building production in a controlled environment offers numerous opportunities to improve sustainability, such as minimizing construction time, increasing quality of buildings, enhancing occupational health and safety and reducing construction waste. The three most significant factors in IBS ecological performance demonstrate the importance of managing resources and waste. Effective planning for materials and waste minimization is imperative.

IBS applications were proven to have the ability to reduce waste for both design and construction phases (Jaillon et al., 2009). The adoption of IBS applications contributes to both material conservation and waste reduction (Jaillon and Poon, 2008). Early consideration in the design stage will contribute to waste avoidance through efficient use of construction materials and the planning of production processes. It is important for IBS component manufacturers to improve operations by ordering material precisely and on a just-in-time basis, considering appropriate storage facilities and eliminating defects and damage. Modular coordination of materials such as brick, timber or steel components should be promoted to standardize components and minimize double handling and offcuts.

Victoria's Environment Protection Act (1970, s.11) states that waste should be managed in accordance with the following order of preference:

avoidance; reuse; recycling; recovery of energy; treatment; containment; disposal.

The identification of waste generation as the most critical factor in improving IBS applications echoes the notion that waste needs first to be avoided and its generation process properly managed to achieve a sustainability objective.

The second most significant factor is waste disposal, also relating to the waste management process. The factor is the least preferable solution in the above waste hierarchy. However, this factor can contribute to sustainability by encouraging IBS stakeholders to

develop efficient strategies to dispose of construction materials. Schultmann and Sunke (2007) highlighted that the reduction of waste through the establishment of closed-loop material flows alleviates sustainable development constraints. Methods and techniques in waste disposal need to be strategized to allow stakeholders to take advantage of material recovery. IBS applications allow systematic and coordinated disman- tling of building components, which can be reused at a different location. In this context, focus for the long term should be on encouraging an effective waste disposal process. As shown in Table 3, cooperation among the builders to promote recycling and reuse is very important. Involvement from all participants at the project level is vital to achieving such an objective. In this study, local and regional characteristics and physical environments are also among the important elements to be considered.

A full understanding of the local resource availabil- ity and capacity is vital to ensuring that material consumption issues are properly considered in IBS project delivery. The qualitative analysis of this study has resulted in the recommendation of seven action plans for material consumption, five action plans for waste generation and four action plans for waste disposal (Table 4). These action plans present the main process and steps of working through each critical factor to improve sustainability. With these plans, designers may follow consistent approaches while responding to sustainability concerns from all stakeholders. Intensive evaluation of applicable materials will help the government determine and control the balance between import and export of construction materials and minimize material price fluctuation. Initiatives of using local materials and recycling can serve as a catalyst for the local economy and close the loop of resource regeneration. Technologies promoting reuse or long service life, such as durable mouldings and formwork, can contribute to material consumption efficiency.

Conclusion

With proven benefits, industrialized building systems (IBS) can provide the right ingredients for the construction industry's response to sustainability challenges in Malaysia. Against rising interest, existing IBS evaluation criteria and tools do not specifically relate to sustainability. The improvement of IBS environmental performance needs to involve all participants such as developers, designers, contractors and manufacturers to agree upon and prioritize issues and to support design professionals as they exert a major influence on the project outcome.


A systematic strategy to improve IBS ecological performance through decision support to the design phase is presented. Three critical factors are identified to be material consumption, waste generation and waste disposal. T o provide a decision-making frame suited to the subject matter yet conducive to brainstorming, testing of alternatives, and contemplation of pros and cons, S W O T analysis is used to present specific strategies for dealing with the critical factors and provide practical guidelines for IBS designers. T h e research process also helps raise the industry's general awareness of sustainability and highlights the need to make existing evaluation tools capable of responding to new issues. Issues unique to developing countries, through the case of Malaysia, are also given due consideration.

We need a holistic approach to respond to sustainability challenges in IBS implementation. The approach should encompass the entire project development cycle. As the first step, research to date has combined quantitative and qualitative analysis to develop potential strategies for IBS design professionals to respond to, deal with, and maximize benefits from the lzey factors of ecological performance. Ongo- ing work will validate and improve this decision frameworlz for design before moving to consider issues in the construction and operational phases. I t will be interesting to find out the inherent linkages between design decisions and actual sustainability deliverables during other development stages.

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