Integrating sustainability and buildability requirements in building envelopes

The purpose of this study is to present the importance of integrating common features between the Green Mark Scheme (GMS) and the Buildable Design Appraisal System (BDAS) requirements in building envelopes. The study presents the common features that influence both the GM score of the building envelope and the buildability score of the wall system. A case study is developed to show the effects of varying the value of a representative common feature in the GM score and the buildability score. The study finds that lengths of window and wall, and wall materials are the common features that can influence the GM score of the building envelope and the buildability score of the wall system. The case study suggested that the window-to-wall ratio (WWR), which is the representative common feature, shows negative relationship with the GM score of the building envelope and positive relationship with the buildability score of the wall system. The results show that varying the WWR influences the GM score of the building envelope more strongly than the buildability score of the wall system. This seems to imply that building professionals when determining the WWR may have to concern themselves with theGM score of the building envelope more as compared to the buildability score of the wall system. The study suggests that integrating the common features between GMS and BDAS requirements with other relevant factors such as cost, social and environmental impacts of design can help to save workload, time and budget, as well as facilitate the delivery of more reliable design, planning and management from a practical viewpoint.