Environmental and economic implications of building envelope design
There is a wealth literature on operational energy consumption of buildings and how building skins contribute to that. Little is known about the life-cycle environmental impacts of building skins and it is not clear if the operational energy savings that are achieved by improvement strategies in building skin (such as more insulation, external shading devices, PV systems) would indeed result in lower environmental impacts from a life-cycle perspective. Even less clear is how economic and life-cycle environmental impacts of buildings would vary by the changes in architectural design parameters. In the present study, we quantify the variations in operational energy, environmental impacts and costs as a result of change in building skin design and construction parameters. We will examine building envelopes in low-rise office buildings from economic and environmental perspectives. For this purpose, 91 different design combinations of a building envelope are considered with different thermal resistance values of wall, wall-to-window ratios, window types, and frame materials. We then use Environmental Life Cycle Assessment (LCA) to study the variations of design combination with respect to global warming, acidification, eutrophication, and smog formation. Simultaneously, Life- Cycle Cost Analysis (LCCA) is applied to examine the cost changes in design combinations. Then, regression analysis is conducted to find the association between design combinations and changes in environmental impacts and cost fluctuations.