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Energy code requirements for residential construction

Find out how to receive a $150 credit on your permit fee

View a list of what to submit to show compliance with Denver's energy code

All projects submitted for a building permit must adhere to the International Energy Conservation Code (IECC), which was adopted in Denver in 2016. After a year of experience with this code and valuable feedback from customers, we have revised our energy code policy for residential projects.

The revised policy clearly lists the information to include with your building plans for each of the IECC's paths (prescriptive, simulated performance, or energy rating index [ERI]). It also covers what needs to be submitted to the inspector before a Certificate of Occupancy can be released.

After a 30-day grace period, the policy will be in effect on December 7th.


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A summary of the changes by policy section

Scope and Applicability

This revised IECC policy only applies to projects governed by the IECC's residential provisions. A similarly revised policy for commercial projects is forthcoming.

Part II. Information to be Submitted on Construction Documents for All Projects

The items listed in part II are not new; most are stated in the code itself. However, our previous policy draft did not make it clear that items A through L in part II apply to all projects, regardless of whether you are using the prescriptive, performance, or ERI path.

As a reminder, include the location of vapor retarder when you mark the location of the building thermal envelope on your plans, details, and cross-sections.

The exceptions are new:

  • If your project consists of only interior renovations to an existing, you do not need to submit air barrier details or Manual J, S, or D calculation packages.
  • If you are doing an addition but are not increasing the existing floor area by more than 30%, you do not need to submit air barrier details or Manual J, S, or D calculation packages. Basement square footage is not counted as part of the existing floor area.

Part III. Additional Information to be Submitted Specific to Certain Projects

This section clarifies when additional information may be required, such as REScheck reports for projects doing the total UA alternative in the prescriptive approach, or compliance reports for the simulated performance alternative.

  • For additions larger than 30% of existing floor area: To show that the new construction and any improvements to the thermal envelope meet the intent of energy codes, projects may elect to perform a blower door test demonstrating that the structure's air changes per hour (ACH) are either the same or better than existed before the addition. Doing so will require a baseline blower door test performed before construction starts. The requirements for the final test vary slightly depending on whether the project is taking a prescriptive or performance approach. Details are located in the policy. 
  • While the above option may be preferable for additions to older homes, as an alternative, projects using the prescriptive path could do only one blower door test at the end to confirm the structure meets 5 ACH or better.

In part III, all of subsections D and E are new. Subsection D introduces a new option for existing buildings where the scope of work makes it challenging to isolate and measure the energy efficiency of the new/changed portion (e.g., pop-tops/additions, remodels, repairs, change of occupancy). These projects could compare ERI scores to demonstrate that the new structure uses the same or less energy as the original structure. 

Part IV. Using an Energy Rater

Our requirements for using an energy rater used to be contained only in a separate policy, IRC N1105 & IRC N1106 (PDF). This policy has also been updated and still exists, but its contents are now also reflected in part IV of the revised IECC residential policy. Our goal is to maintain all residential energy code information in one document. There are some changes:

  • Energy raters need to be HERS accredited and must submit proof of their certification;
  • Energy raters are responsible for inspecting and confirming that air barrier, insulation values, and blower door results meet or exceed both design expectations and the requirements of the 2015 IECC; and
  • A $150 discount on permit fees (up from only $75 before) for using an energy rater to inspect and verify the home's energy code compliance. The form to apply for this discount is located at the end of the policy.

Part V. Information to be Submitted at Final Inspection

This is a new section to clearly list what documents you will need to be prepared to show your inspector, before a Certificate of Occupancy can be released. The only new item in the list is the energy rater inspection verification form for projects that had an energy rater inspect and confirm their air barrier, insulation values, and blower door results.

View all of our building codes and associated policies at