Defining the “Smart” Energy Retrofit

This research uses a case study of a prototypical higher education campus renovation project to investigate and model a “smart” energy retrofit—one that considers the carbon payback as well as the cost payback of the renovation to target strategic energy retrofit measures that provide maximum carbon reductions with minimum carbon and cost investment. The study tested an innovative process that incorporated several interrelated analytical methodologies to determine the optimal building renovation scope for maximum carbon reductions. These included thermal analysis to quantify the thermal resistance of individual components of the envelope, energy modeling to calibrate and determine whole building performance, and life cycle assessment to calculate embodied impacts. Using these tools in concert with cost estimating allowed the design team and owner to evaluate the financial and environmental return on investment of potential interventions in the existing building envelope, building systems, and primary energy sources. This case study demonstrates a replicable process to optimize both embodied and operational carbon through iterative analysis. The process illustrates that not all energy-conserving measures are worth pursuing when taken in the context of life cycle carbon and costs-a deep energy retrofit is not necessarily a smart energy retrofit. Additionally, energy retrofits should consider solutions that are appropriate to make immediate reductions while enabling further reductions through the future availability of greener energy sources. To reduce emissions from the building sector and achieve critical climate targets, the design and construction industry must rigorously analyze tradeoffs of embodied versus operations impacts, rather than defaulting to traditional best practice assumptions to meet critical climate targets.