Building Energy Codes

Building construction
Code Adoption Technical Assistance
Do you have a question about the building I-codes, how to review or inspect for a measure, how the I-codes interact, or how to comply? We can help! If you're in Colorado, you can submit a question to our free Code Helpline. Our subject matter experts will respond to you via email within two business days. 
We created an Energy Code Adoption Toolkit that includes a guide on the significant changes from previous editions of the International Energy Conservation Code (IECC) to the 2021 IECC, cost comparisons between code editions, examples of stretch codes from other jurisdictions, and code compliance checklists. CEO provides no-cost technical assistance to jurisdictions to support the adoption of new codes and code enforcement. Technical assistance can be customized to a jurisdiction's needs. Assistance may include:
  • A review of a jurisdiction’s current code and policies
  • Education for stakeholders about the major changes in new codes compared to the jurisdiction’s existing codes
  • Recommendations for proposed code amendments tailored to the jurisdiction
  • Subject-matter expertise to answer questions and address concerns about code-related issues, for example, in city council or county commissioner public hearings
  • A review of a jurisdiction’s existing building code implementation and enforcement policies and proposed changes that align with the new codes, as amended and adopted by the city or county. 

    For more information about technical assistance, see this flyer. To request technical assistance, please fill out this short form

    Energy Code Training

    Interested in getting code training? The Colorado Energy Office (CEO) provides energy code education at no cost to building departments and stakeholders to support jurisdictions with adopting new codes. CEO offered its popular Wednesday webinar training series from October 2020 through May 2021 taught by Colorado's esteemed I-codes experts and trainers. If you missed a webinar, we record each training so that you can view it on demand. See a list of and links to each of our previously recorded webinars in our Energy Code Adoption Toolkit or watch the videos. Xcel Energy is continuing the series of webinars in Summer 2021 - please see this flyer for topics and to sign up!
    In addition to the one-hour webinars, our codes experts also provide in-depth, customized trainings across the state. Customized training is available upon request; simply fill out this short form. Trainings can be scheduled for local government staff such as code officials, inspectors, and planners as well as other building industry stakeholders including builders, designers, engineers, contractors, and architects. 


    Energy Codes in Colorado

    Colorado has no statewide building or energy code; codes are primarily adopted and enforced locally except where noted below.

    • State Buildings Program, part of the Office of the State Architect is responsible for establishing 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, adopts and enforces building codes for manufactured, factory-built, and modular housing, and hotels, motels, and multifamily buildings in jurisdictions with no codes.

    CEO has compiled a list of Colorado Building and Energy Codes by Jurisdiction. More than 2.7 million Coloradans, or 48% of the state's population, live in a jurisdiction that has adopted the 2018 IECC. More than 60 jurisdictions have adopted it so far, with many more in the process or under consideration. More than 4.9 million Coloradans, or 86% of the state's population, live in one of the 156 jurisdictions that have adopted a high-efficiency energy code—the 2018, 2015, or 2012 IECC. 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

    CEO recommends that jurisdictions update their building codes on a regular cycle, typically every three years, which is how often the International Code Council updates its model codes. Incremental changes are much more manageable to adopt when codes are updated on a regular cycle as opposed to skipping several editions of the code. Failing to update building codes regularly can be challenging since there aren’t resources that compare much older codes to newer ones and changes add up when codes are updated more than a decade apart. 

    CEO is a member of the Colorado Energy Code Compliance Collaborative. The Collaborative consists of 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. New members are always welcome! For more information or to join the Collaborative, please see this fact sheet


    Why Building Energy Codes are Important

    Buildings account for about 40% of energy used in the United States and represent the fourth largest source of emissions here in Colorado. Building energy codes establish minimum construction or major renovation requirements that enable buildings to use energy more efficiently. But building energy codes do more than improve the efficiency of buildings; they also help ensure the safety, durability, sustainability, and affordability of homes and buildings in your jurisdiction. Based on building science and physics principles, life-safety aspects of the energy code include moisture management (avoiding mold, mildew, and rot), indoor air quality, increased fire protection, and protection during severe weather. 

    Did you know that energy codes are the only building codes with a return on investment? That’s because building to newer energy codes pays building owners back by way of reduced operating and utility costs. In fact, moving from the 2009 to the 2015 or 2018 IECC saves an average of $4,491 on a 30-year mortgage here in Colorado, with a net-positive cash flow in under a year. 


    State Law Sets Building Energy Code Requirements

    Colorado House Bill 19-1260 updated the 2007 state law that established a minimum building energy code. Effective August 2, 2019, the law requires local jurisdictions in Colorado to adopt and enforce one of the three most recent versions of the International Energy Conservation Code (IECC) upon updating any other building code. Jurisdictions do not need to modify their timeline for adopting new building codes; they simply need to adopt one of the three most recent versions of the energy code at the same time they adopt or update other building codes, if they have them.   

    The legislation also encourages jurisdictions to report to the Colorado Energy Office (CEO) any updates to their building and energy codes within a month of the change. CEO created this form for jurisdictions to report this information. Alternatively, you may report this information by emailing Kim Burke at