Design variables affecting the environmental impacts of buildings : a critical review

Building sector is responsible for a large portion of global environmental impacts. The life-cycle environmental impacts of a building are largely determined by decisions made during design process. For making eco-friendly building design decisions, a prerequisite is to understand which design variables affect the environmental impacts of a building over its life cycle is. This research conducts a critical review to identify design variables affecting the environmental impacts of buildings at three design stages during the design processes. Publications between 2010 and 2022 (inclusive) are examined and 50 papers are selected for review. The results reveal that eight design variables in early design stages, including (1) building aspect ratio, (2) window-to-wall ratio, (3) shading area, (4) building orientation, (5) number of floors, (6) building shape, (7) floor area and (8) floor-to-floor height, have an impact on a building's life-cycle environmental impacts. In detailed design stages, there are four kinds of design variables linked with the environmental impacts of a building: (1) types of building components, (2) sizes of building components, (3) types of building materials, and (4) thickness of building materials. Types of finishing materials are closely related to the environmental impacts of a building in construction design stages. The findings of this research help understand the contributors to the environmental impacts of a building from the perspective of building design. The findings also provide a future research direction on design variables for making eco-friendly building design.