External Shading Devices: Should the Energy Standard Be Supplemented with a Production Stage?

Abstract

The Israeli Standard SI5282 rates buildings according to the operational energy (OE) used to support their heating, cooling, and lighting needs. When it was proposed, OE was generally considered to be derived from fossil fuels, such as coal. However, at present, Israel is in the process of transitioning to cleaner energy sources, such as natural gas and renewables. In light of this change, the question that guided this study was as follows: should the production (P) stage of external shading devices be taken into account alongside the OE stage? In this study, we aimed to evaluate the P (environmental damage) and OE (environmental benefit) of five external shading devices with equivalently high energy rates that were installed in a typical office building using cleaner OE sources. We evaluated the environmental impacts using the ReCiPe2016 method. The results indicated that the P stage of the five shading devices led to significantly different degrees of environmental damage, thus reducing the environmental benefits related to the OE stage. Therefore, the five similarly rated shading devices could no longer be considered as equivalent sustainable alternatives. As such, we recommend that the energy rating be supplemented with a P stage environmental evaluation.