Much of the information presented in this summary is drawn from the U.S. Department of Energy’s (DOE) Building Energy Codes Program and the Building Codes Assistance Project (BCAP). For more detailed information about building energy codes, visit the DOE and BCAP websites.

Colorado is a home rule state, so no statewide energy code exists, although state government buildings do have specific requirements. Voluntary adoption of energy codes is encouraged and efforts through grants are directed toward informing local jurisdictions of the benefits of energy efficiency standards and providing materials and training to support code implementation. Compliance is based on the requirements of the local jurisdictions.

Any county or municipality that had a building code in place was required to adopt 2003 IECC or 2006 IECC as the minimum energy code standard by July 1, 2008 (C.R.S. § 30-28-201). Eight-three percent of Colorado's population was covered by the 2009 IECC or above and 95% of all new homes being built are under the IECC 2009, according to BCAP. 

Local enforcement agencies in jurisdictions that have adopted building codes are required to enforce the provisions of the residential energy code at the local level, but may adopt their own requirements without state approval. Inspections are required as a part of the established building inspection process. No special inspection requirements exist for state-owned and state-funded buildings. These inspections are handled by the local enforcement agencies.

Solar Energy

Builders of single family homes are required to offer solar energy as a standard feature to all prospective homebuyers (C.R.S. § 38-35.7-106). Builders are required to give the buyer the option to either have a photovoltaic (PV) system or a solar water heating system installed on their new home or to have all the necessary wiring and plumbing installed so that they can easily add a solar system at a later date. The builder must also provide the buyer with a list, maintained by the Colorado Energy Office, of every solar installer in the area, so the buyer can obtain expert help in determining if their home's location is suitable for solar and what the estimated cost savings would be.

Appliances and Fixtures

Builders of new detached single-family homes are required to offer certain energy- and water-efficient products if the buyer is under contract (C.R.S. § 38-35.7-107). The builder must offer water-efficient toilets, faucets, and shower heads and provide the option for the homeowner to purchase Energy Star-rated dishwashers and clothes washers and various water-saving landscaping devices if such items are included in the sale of the house.