Embodied and Operational Energy Analysis of Passive House–Inspired High-Performance Residential Building Envelopes

Abstract

High-performance building envelopes are designed to achieve target reductions in operational energy (OE). However, these wall assemblies often require initial, upfront investments in material cost and manufacturing energy. To this end, this study assessed the total life cycle energy (LCE) and life cycle cost (LCC) of five Passive House–inspired building envelopes in the United States via life cycle assessment (LCA) and life cycle cost analysis (LCCA), respectively, across four US climate zones. The results indicate that, regardless of climate, wood-framed wall systems were most cost-effective and exhibited lower LCE and LCC compared with the other wall assemblies investigated herein. Double-stud walls in particular were found most environmentally and economically cost-effective in all climates. In addition, the results specifically highlight the law of diminishing returns in terms of OE reduction through more insulative envelopes, as the impacts of embodied energy (EE) outweighed the benefits of a reduced OE in some cases. Finally, depending on climate and building archetype, the total EE of the residential buildings accounted for 22%–91% of the total LCE over a 60-year period—a result that highlights a grand opportunity to reduce the EE and, thus, total LCE of high-performance residential construction in the US.