As cities adopt energy benchmarking and higher performance targets, inaccurate accounting of spandrel performance in glazed wall assemblies introduces risk for developers and building owners alike. Drawing from Phase 1 of a multi-phase research program funded by the Charles Pankow Foundation, this paper explores what we know—and what we don’t—about spandrel thermal performance. The technical findings are situated within the broader context of the urban-scale environment. The paper outlines how current standards fall short in regulating spandrel assemblies, leading to performance overestimation and barriers to innovation. It also highlights how these limitations create financial risk in cities across North America.
This paper was presented at the CTBUH 2025 International Conference.