DOE Building Energy Codes Program Infographics
The US Department of Energy (DOE) Building Energy Codes Program (BECP) tracks and analyzes data related to the adoption, compliance, and implementation with the latest model energy codes. The following maps and graphics provide additional context to improve understanding of energy codes across the country.
Estimated Model Energy Code Improvement
The Estimated Improvement in Residential and Commercial Energy Codes graph outlines the estimated national average energy use reduction in model energy codes from 1975 to the present. Green down arrows indicate a more efficient code while red up arrows indicate lost efficiency from code to code. Data presented in this graph is based on total building energy use.
Site Energy Index by State
One way to understand how each state energy code performs is to compare it to a single baseline code. The Residential Energy Code: State Energy Index Relative to 2021 IECC and Commercial Energy Code: State Energy Index Relative to Standard 90.1-2019 maps highlight the percent difference between the state site energy index (SEI) and the SEI of the 2021 IECC and ASHRAE 90.1-2019. Shades of green indicate the level of energy code efficiency. Dark green indicates the state code is as or more efficient than the 2021 IECC or 90.1-2019, where shades of turquoise and gray indicate a less efficient state code. States in white either do not have a statewide energy code or have a custom code that DOE did not analyze.
The Residential Site Energy Index by Code & State and the Commercial Site Energy Index by Code & State graphs compare each state's modeled SEI for the previous residential IECC and commercial ASHRAE Standard 90.1 editions (line chart) to the state's current residential or commercial energy code (dots). If the state's current code has a higher SEI than previous model codes, the code is less efficient, and if lower, the state code is more efficient.
Municipal Building Codes and Ordinances
To understand which energy codes are being implemented at the municipal level, the Municipal Residential Energy Code Efficiency and Municipal Commercial Energy Code Efficiency maps assess the energy code efficiency of the current residential and commercial energy codes being enforced in major cities across the country. Cities were selected based on the amount of construction activity in the surrounding metro area. Cities in dark green states have authority to adopt any energy code, cities in light green states can only adopt an energy code that is more efficient than the state code, and cities in tan states must enforce the state code. The circle size is proportional to construction volume, and color indicates estimated city code equivalency.
In addition to energy code adoption and implementation, many jurisdictions are adopting building requirements addressing on-site solar and electric vehicle charging infrastructure. There are two primary ways to adopt these policies, either through the building code or a local ordinance.
The State and Local Electric Vehicle and Solar Building Requirements map provides a high-level overview of where policies to support electric vehicle and solar infrastructure in buildings are adopted.
Historical State Energy Code Adoption
The Historical State Energy Code Adoption visualizations depict state residential/commercial energy code adoption trends and efficiency levels over time. The State Energy Code Efficiency Maps show residential/commercial code equivalency from 2016 to the present, based on the DOE methodology and underlying state energy index analysis informing the BECP State Portal. The State Energy Code Timeline provides additional state adoption data going back to 1989, reflecting only the adopted model code and any strengthening or weakening amendments included.
Use the slider at the top right of the map to move through the years and see how energy codes have progressed at the national and state levels over time. Hover over a state to view the state name, adopted energy code version, energy code efficiency category, year the code was adopted, and number of years the code was in effect.
Existing Buildings
Until recently, a mechanism to holistically address energy use in existing buildings did not exist. However, the introduction of Building Performance Standards (BPS), which set energy or other performance targets for existing buildings to achieve over a given time frame, changed that. The State and Local Building Performance Standards map highlights where a BPS is either in place or is being considered at the state and local levels.
FIELD ASSESSMENTS
The DOE BECP has developed research methods to support states in studying the impacts of their building energy codes. The objectives of energy code field studies are to document typical design and construction practices, target areas for improvement through workforce education and training initiatives and quantify energy efficiency and environmental impacts in buildings. States are encouraged to conduct field studies every 3-5 years to validate the effects of codes and other energy-efficiency programs and benchmark technology trends in residential and commercial construction.
The Residential Energy Code Field Studies and Commercial Energy Code Field Studies maps highlight states that have conducted field studies in single-family, multifamily, or commercial buildings within the last decade. Although DOE funded many of these studies to demonstrate early success, states and jurisdictions have utilized DOE methodologies to fund and facilitate studies outside the DOE program. Read more about states that have conducted a field study according to a DOE methodology.