An Evaluation Framework for the Integrated Design Process of Sustainable High-Performance Buildings

Abstract

Integration of disciplines and project participants is widely prescribed as a remedy to improve effectiveness and efficiency of construction projects. In the context of Sustainable High-Performance (SHP) projects, the Integrated Design (ID) process encourages implementation of systems-thinking and early intense collaboration of project stakeholders during the design phase. The desired outcome in this context would be buildings which not only have superior energy and sustainability performance over their life-cycle but also are cost effective. This study attempts to: 1) identify the evaluation factors/items that could be used to measure the team performance in the ID process of SHP projects; 2) develop an evaluation framework for the ID process based on a systematic evaluation model; 3) validate the proposed evaluation framework; and 4) test the hypotheses that: a. `More integrated design teams are able to achieve more successful SHP project outcomes'. b. `More integrated design teams are able to gain more total LEED credits for their SHP designs'. c. `More integrated design teams are able to gain more LEED credits in the Energy & Atmosphere category'. To achieve the research objectives, a mixed-method (qualitative-quantitative) research methodology was applied. First, qualitative research (case-study and interview) and literature review were used to identify the critical factors in ID process and create a pool of the items that could be used to assess the performance of integrated design teams. These evaluation items were generated based on the Context, Input, Process, and Product (CIPP) evaluation model. In the next phase, the evaluation items were tested for content validity through expert review. The outcome was the development of the evaluation framework for the ID process of SHP projects. In the next phase of research, the proposed evaluation framework was validated through statistical analysis of a cross-sectional questionnaire survey of projects certified under the Leadership in Energy and Environmental Design (LEED) rating system. Internal consistency and multiple regression analysis were applied for assessing the reliability and validity of the proposed framework. An Integrated Design Process Evaluation Framework was constructed with four components: a) an evaluation model (CIPP model), b) evaluation factors (27), c) evaluation items (65), and d) a measurement framework with three indices (Challenge Index (CI), Integration Assessment Index (IAI), and Performance Index (PI)). The results of statistical analysis showed the reliability and validity of the framework. The results also confirmed the research hypotheses and indicated that there is a significant positive effect of the integration of design teams on their achieved outcomes.