Identifying influential architectural design variables for early-stage building sustainability optimization

Architectural design variables (ADVs) highly influence a building's sustainability performance. Thus, identifying which ADVs are most influential in a building's early stages is of great significance, especially when using computational building design optimization tools. Currently, sensitivity analysis based on computer simulations is the most commonly used means to identify which ADVs are the most influential in the early stages. However, we suggest that a stakeholder perspective should also be considered as stakeholders possess domain-specific knowledge and expertise as well as a contextual understanding that can greatly enhance the development and deployment of building design optimization tools. To explore the above, we combined a literature review with survey data from 24 architects and sustainability consultants in the Nordics. Surprisingly, we found that the influential ADVs in the literature do not always align with those of our surveyed stakeholders. For example, we found that the literature considers building plan, window-to-wall-ratio (WWR), and wall material as the most influential ADVs, which contrasts with storey number, storey height, WWR, roof material and wall material considered by stakeholders to be the most influential. We also found that the most influential ADVs differ across different sustainability optimization objectives, and that these also differ from the literature. Despite our limited survey sample, our study provides insights into influential ADVs and as such has implications for the development, use, and performance of computational building design optimization tools.