Building Code Changes for Existing Buildings

As of March 1st, 2023, the city has changed the permit process for replacing a unitary air conditioner or condensing unit, natural gas heating system, or natural gas water heater in commercial and multifamily buildings. These systems will no longer be allowed to go through the quick permit process. Instead, the process to replace these systems with a like-for-like replacement is the same as the permit process for heat pumps.  

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Section 10-20 of the municipal code directs the city to make updates to the energy code by January 1, 2025 related to requirements for partial electrification of existing buildings. The proposed requirements relate to electrification of specific types of furnaces and water heaters at end of system life in existing commercial buildings. We want to clarify that the city has not yet made those changes and will not do so before January 1, 2025.  

We will announce a process in early 2025 to update the energy code with stakeholder engagement as part of the regular update to Denver’s building codes. In the interim, the provisions of the 2022 Denver Energy Code for space and water heating continue to apply.  Please sign up for CPD’s newsletter to be informed of the process to update the energy code.

No later than January 1, 2027, the Denver Building and Fire Code will be amended to further expand the electrification requirements:  

• When it is time for you to replace your gas-fired boiler used for space heating the new equipment that you install must meet at least 50% of your space heating needs with electric space heating. The other 50% can be met with another gas-fired boiler, unless you qualify for an exemption. If you do install a replacement gas-fired boiler to provide supplementary heat or due to an approved exemption, you must do at least two (2) of the following:
  • Submit an Electrification Feasibility Report
  • Get an analysis of the building envelope, ventilation requirements, and energy load prepared by a registered design professional. You will also have to right-size the equipment based on the Denver Building and Fire Code. 
  • Pressure test all the natural gas piping in the building.
• When replacing a gas-fired boiler used for water heating, the new equipment you install must meet at least 50% of your water heating with electric water heating. The other 50% can be another gas-fired boiler, unless you qualify for an exemption. If you do install a replacement gas-fired boiler, to provide supplementary heat or due to an approved exemption, you must do at least one (1) of the following: 
  • Submit an Electrification Feasibility Report
  • Pressure test all the natural gas piping in the building.
• If you replace an air conditioner that serves space you also heat, you must replace it with electric equipment that does both heating and cooling (like a heat pump). Any other space heating equipment in the building should be used for supplementary heat only.  

As with the 2025 updates, there will be exemptions for emergency replacement and economic hardship available. Denver’s Office of Climate Action, Sustainability and Resiliency will review exemption applications to make a final determination.

Planning for Equipment Replacement