The Impact of Minimum Energy Performance Standards for Buildings

In the US alone, signatory firms reported 13,073 whole-building projects in 2022, totaling 2.2 billion gross square feet. The country's national weighted average pEUI reduction was 46 percent—a few percentage points below the overall (global) average. 

The latest report also offers a state-by-state breakdown of pEUI reduction and the magnitude of total number of whole-building projects reported within the state. As one might expect, due to its size, population, and having one of the most stringent energy codes in the country, is there any surprise that California—which exhibited over 500 reported projects—would lead all states with an overall pEUI reduction of 55 percent? What might surprise you is that Wyoming is not far behind at 49 percent—this despite having no statewide code and one of the more carbon-laden state-wide energy resource mixes. However, with less than 100 projects reported across Wyoming (e.g., could be based on 1 project or as many as 99), these figures are more likely a testament to the sustainable design leadership of the 2030 signatories doing work in the state. Nevertheless, it stands to reason that the regulatory minimum—each state's energy code—would "bake in" a minimum predicted pEUI reduction threshold. . 

Energy code-induced minimum pEUI reductions per state

The US Department of Energy's (DOE's) Building Energy Codes Program (BECP) tracks energy codes at the state level and provides state-specific energy code resources, including a "Code Efficiency Category" for both commercial and residential energy codes:

• The Residential Code Efficiency Categories reference generally equivalent editions of the International Energy Conservation Code (IECC). 

• The Commercial Code Efficiency Categories reference generally equivalent edition of ASHRAE Standard 90.1.

Using the US DOE's published determinations, the minimum percent pEUI reduction relative to the 2030 baseline can be determined for both the IECC and ASHRAE Standard 90.1. How might each state's code-based minimum percent reduction compare with the percent reduction reported for the 2030 Commitment? 

Gauging a state's pEUI reduction relative to the energy code minimum 

If one were to compare each state's Commercial Code Efficiency Category to its predicted energy use intensity reduction as reported by AIA in the latest 2030 By the Numbers report, an interesting story emerges. 

For example, whereas California's commercial energy code sets an overall pEUI reduction at 50 percent below the 2030 baseline, a reported 55 percent reduction is just marginally better than code. 

By comparison, Ohio's Commercial Code Efficiency Category sets the minimum at 28 percent; yet the 2030 outcomes were reported at 47 percent — a 19 percent reduction beyond code.

The minimum standard matters

Running this comparison across every state with an energy code seems to make two things clear:

• Approximately 74 percent of the jurisdictions' pEUI figures as reported for the 2030 Commitment are within 10 percent of the jurisdiction's current Commercial Code Efficiency Category performance threshold. 

• As such, the minimum standard set by a jurisdiction's energy code has a profound impact on pEUI reduction.

This analysis underscores a basic notion that codes have deep and transcendent impacts. In particular, energy codes establish a minimum standard for building design and construction to enhance energy efficiency, reduce negative environmental impacts through greenhouse gas emissions, increase energy costs savings across real estate assets, and generally support the long-term economic viability of their respective jurisdictions.

Qualifiers: 

a. Most certainly, many of the projects reported were permitted and began construction before some states' newest energy codes took effect. 

b. The AIA reported figures are from 2022.

c. The US DOE Commercial Code Efficiency Category is based on information as this writing in November 2023.