Building Energy Codes

Energy code training

Interested in getting code training? The Colorado Energy Office (CEO) and Xcel Energy provide energy code education at no cost to building departments and stakeholders to support jurisdictions with adopting new codes. 

CEO is continuing its popular Wednesday webinar training series taught by Colorado's esteemed I-codes experts and trainers. CEO will continue offering these webinars through June 2024.

Register for CEO I-Code expert webinars

If you miss a webinar, we record each training so that you can view it on demand.

Watch previous webinars

In addition to webinars, our code experts provide in-depth, customized training across the state for local government staff, such as code officials, inspectors, and planners, and other building industry stakeholders, including builders, designers, engineers, contractors, and architects. Training may cover the 2021 International Energy Conservation Code (IECC), including identical provisions found in older codes; energy-related chapters of other 2021 I-codes; and advanced stretch codes.

Request customized training

Xcel Energy also offers energy code training and technical assistance for jurisdictions within its service territory.

Visit Xcel’s Energy Codes Program webpage

Building construction

I-Codes Technical Assistance

The Colorado Energy Office is offering free technical assistance for jurisdictions adopting the 2021 International Energy Conservation Code (IECC) and energy-related chapters of other 2021 I-codes. Based on the needs of your jurisdiction, technical assistance can help local governments research and understand the new code language, estimate cost impacts, and gain stakeholder support.

Request technical assistance

Assistance may include:

  • Reviewing current code and policies
  • Educating stakeholders about major changes in new codes compared to existing codes
  • Recommending code amendments tailored to the jurisdiction
  • Answering questions and addressing concerns about code-related issues, for example, in city council or county commissioner public hearings
  • Reviewing existing building code implementation and enforcement policies and proposing changes that align with new codes, as amended and adopted by the city or county.

If you have questions about the building I-codes, you can submit a question to our free Code Helpline and our subject matter experts will respond via email within three business days.


Energy code adoption toolkit

The Energy Code Adoption Toolkit includes a guide outlining significant changes in the 2021 International Energy Conservation Code (IECC) from previous editions, cost comparisons between code editions, examples of stretch codes from other jurisdictions, and code compliance checklists. 


Energy code requirements in Colorado

In 2019, Colorado passed a law that required local jurisdictions to adopt and enforce one of the three most recent versions of the IECC when adopting or updating any other building code. In 2022, the legislature passed a new law updating the minimum building energy requirements. The law now requires local jurisdictions to adopt the 2021 IECC and the state’s model electric ready and solar ready code when adopting or updating any other building code between July 1, 2023 and June 30, 2026. Beginning July 1, 2026, local jurisdictions must adopt the state’s model low energy and carbon code (which the Energy Code Board will develop by June 1, 2025) when adopting or updating any other building code. Jurisdictions may make amendments to the energy code based on local needs, so long as the amendments "do not decrease the effectiveness or energy efficiency of the energy code."

Colorado has no statewide building code; building codes are primarily adopted and enforced locally except where noted below. Pursuant to HB22-1362, the agency responsible for adopting and enforcing codes in the following circumstances must adopt the 2021 IECC and the model electric ready and solar ready code by January 1, 2025.

  • The State Buildings Program, part of the Office of the State Architect, establishes minimum building codes for all construction by state agencies on state-owned or state lease-purchased properties or facilities.
  • The Colorado Department of Public Safety, Division of Fire Prevention and Control, adopts building codes for the construction of public K-12 schools and junior colleges. 
  • The Division of Housing’s Building Codes & Standards Section, part of the Department of Local Affairs, enforces codes for manufactured homes built to HUD codes standards, adopts and enforces building codes for factory-built housing (also known as modular housing), and applies installation standards to all manufactured housing (including HUD, factory-built/modular). The Division also adopts and enforces building codes for site-built hotels, motels, and multifamily buildings in jurisdictions with no codes. 

Building and energy codes by jurisdiction

CEO has developed a map of Colorado Building and Energy Codes by Jurisdiction (see the “details” tab for instructions on how to access the data tables). More than 62% of the state's population lives in one of the 55 jurisdictions that have adopted the 2021 IECC to date, while nearly 95% of the state's population lives in one of the 208 jurisdictions that have adopted a high-efficiency energy code (2021, 2018, or 2015 IECC).

CEO recommends that jurisdictions update their building codes on a regular cycle, typically every three years, in line with updates to the IECC. Incremental changes are much more manageable to adopt when codes are updated on a regular cycle. Failing to update building codes regularly makes future code updates more challenging, since fewer resources are available and more changes are required at once.. The 2019 legislation also encourages jurisdictions to report any updates to their building and energy codes to the state within a month of the change.

If you notice an error in codes by jurisdiction list or would like to notify the Colorado Energy Office of an update to your jurisdiction's codes, please email us at adam.berry@state.co.us.


Colorado Energy Code Collaborative

The Colorado Energy Code Collaborative includes state agencies (CEO and DOLA), code officials, builders, energy raters, utilities, energy advocates, and other stakeholders who are interested in working together to improve and advance energy code compliance in Colorado. For more information or to join the Collaborative, please email Christine Brinker with the Southwest Energy Efficiency Project at cbrinker@swenergy.org.


Why building energy codes are important

Buildings account for about 40% of energy used in the United States and are among the top five largest sources of emissions in Colorado. Building energy codes establish minimum requirements for new construction and major renovations, enabling buildings to use energy more efficiently and saving building owners and tenants money on operating and utility costs. These codes also help ensure the safety, durability, sustainability, and affordability of homes and buildings  through moisture management, improved indoor air quality, better fire safety, and increased protection from severe weather. 


Supporting the energy efficiency workforce

The Colorado Energy Office, through a partnership with Energy Smart Colorado, provides partial scholarship reimbursements for individuals in mountain, rural, or other underserved communities in Colorado to maintain or obtain their Building Performance Institute (BPI), RESNET HERS Rater or Rating Field Inspector (RFI), or ASHRAE certifications through training, exams, or continuing education courses. Small grants or reimbursements are also available to BPI, RESNET, or ASHRAE-certified professionals to assist in the purchase, maintenance, calibration, or upgrade of energy testing equipment. This funding supports a geographically diverse energy efficiency workforce with a broad skill set, enables regional organizations to conduct residential and commercial building energy assessments to identify energy-saving opportunities, and empowers local governments to adopt advanced building energy codes.