A methodology to quantify the impact of building energy code upgrades on building energy savings: A case study on small offices

In the United States, building energy codes, which set minimum efficiency requirements for new buildings, are commonly used and periodically updated to improve energy efficiency of new buildings and reduce their energy consumption over their service life. Knowing the savings impacts of the energy efficiency measures (EEMs) in the codes is very helpful for jurisdictions considering adoption of newer codes. This paper proposes a novel methodology to analyse and rank the impacts of individual EEMs on commercial buildings while accounting for the interactions of the EEMs. A case study is performed on a prototypical small office building in three climate zones. The impacts of multiple EEMs, representing changes in requirements through five editions of ASHRAE 90.1, were evaluated. The results indicate that the lighting-related EEMs have the most significant impacts on energy savings across all three climate zones; the night setback control requirement for cooling generates high savings in hot climates; and the improved envelope insulation and outdoor air control requirements can bring important savings for buildings in cold climates. These findings can help policymakers understand the importance of the EEMs and make informed decisions on their code adoption.