Assessing cement blocks the context of sustainable construction

Abstract

The task of assessing cement blocks represents an important strategy in the sustainable design and construction of a building. A principal challenge is the identification of assessment criteria based on the concepts and principles of sustainability, and the process of prioritizing and aggregating relevant criteria into an assessment framework .Therefore, the purpose of this study is to fill these gaps by describing the development stages of key assessment criteria used within an assessment tool under development for sustainable CB in the building industry. After conducting a thorough and systematic literature review, a total of 24 sustainability assessment criteria based on the triple bottom line and the needs of building stakeholders were identified. A survey of engineers and architects was conducted to capture their perceptions on the importance of the criteria. Survey questionnaires were randomly mailed and handed over to 231 engineers and 110 architects. Ninety eight (98) effective responses were received, after removing the invalid ones. The response rate was 28.7 per cent. Factor analysis was utilized to group the criteria into assessment factors for modelling sustainability of CB. Ranking analysis revealed that all criteria were highlighted at “high” or “high-medium” levels in selecting cement block building material. A total of 12 criteria was highlighted at the “high” importance level, with aesthetics, embodied energy and initial acquisition cost to make the top three criteria of importance. After the literature review, questionnaire survey and expertise opinion, the top criterion is the embodied energy. The second high criterion is the aesthetics and the third top criterion is the initial acquisition cost of CB. Factor analysis shows that these SACs can be aggregated into six factors, namely; “ environmental impacts”, “resource efficiency”, “waste minimization”, “life cycle cost”, “social benefit”, and “performance capability”. Since these criteria were derived from the survey through expert opinion, consideration of these six criteria in sustainable block making processes and products will ensure sustainability of building projects. According to the six criteria in the cement block material selection, the environmental issues are not strongly considered, despite the need of reducing the environmental impact of building activities. Hence the result is an example of evidence pointing to the trend that environmental aspects are no longer the least important factors for cement block material selection in building projects. The current study contributes to the building industry and sustainability research in at least two aspects. First, it widens the understanding of the degree of importance of sustainable CB making processes and products. It also provides building stakeholders a new way to select CB, thereby facilitating the sustainability of building projects.