Keynote Lecture - Environment: Multi-performance retrofits to existing buildings: Increasing resiliency and reducing the environmental impact of buildings through simultaneous structural and energy retrofits

Existing buildings consume 40 percent of the primary energy in the US. While new zero-energy buildings can gradually reduce this energy use, the existing building stock must be improved through deep energy retrofits to make a... [ view full abstract ]

Existing buildings consume 40 percent of the primary energy in the US. While new zero-energy buildings can gradually reduce this energy use, the existing building stock must be improved through deep energy retrofits to make a significant impact in this sector. Current energy retrofits and research in the US focus primarily on upgrades of mechanical and lighting systems to maximize energy reduction for minimal investment. This incremental approach is effective but limited in the overall energy savings it can generate, as major transformations to the fundamental operation of a building are cost prohibitive. Due to their disruptive nature, structural retrofits offer the physical and economic opportunity to completely transform how a building operates in terms of heating, cooling and lighting – the largest sources of energy use. Consequently, this paper proposes replacing current incremental strategies prevalent in most energy efficiency retrofits with transforming existing buildings though a multi-performance retrofit that (1) improves the structural response to extreme-event loading, (2) maximizes daylight to replace electric lighting, (3) uses low-temperature radiant systems to replace HVAC units, (4) deploys climate-appropriate thermal mass and (5) upgrades the envelope to (6) effectively maximize passive thermal and bioclimatic strategies. This paper documents a database of 25 commercial buildings, primarily from the Pacific Northwest region of the US that have undergone different types of retrofits. Overall, multi-performance retrofits are more expensive than a stand-alone structural or energy retrofits but provide benefits that are not easily quantified. Three multi-performance retrofits are described in more detail to highlight the strategies used and benefits of this approach.