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2025 Denver Building Code Amendments & Energy Code Explained
Denver's 2025 Building and Fire Code took effect Dec. 31, 2025: 2024 I-Codes with Denver amendments, a 2021 IECC-based energy code, transition rules and FAQs.
Direct answer
Denver's current code is the 2025 Denver Building and Fire Code, adopted June 13, 2025 and effective December 31, 2025. It amends the 2024 I-Codes (IBC, IRC, IEBC, IFC, IMC, IPC and IFGC). The exception is the Denver Energy Code, which is based on the 2021 IECC. The city adopted a second printing on November 24, 2025, so work from that printing. Electrical work follows the 2026 NEC, which Denver adopts unamended, the same as Colorado's state electrical code.
What the 2025 Denver code is made of
| Layer | Model basis | Where it is published |
|---|---|---|
| 2025 Denver Building Code (commercial and residential) | 2024 IBC, IRC, IEBC, IMC, IPC, IFGC | 2025 Denver Building Code, 2nd printing (PDF) |
| 2025 Denver Fire Code | 2024 IFC | Denver Building and Fire Codes |
| Denver Energy Code | 2021 IECC | Same page, Denver Energy Code tab |
| Denver Green Code | International Green Construction Code | Commercial and multifamily projects meet some provisions and choose which others to implement |
| Electrical | 2026 NEC (NFPA 70), unamended | Same as the State of Colorado electrical code |
| Zoning and overlays | Denver Zoning Code | Use, form, view planes, landmarks and design review are separate from the building code |
The 2022 Denver Building and Fire Code (4th printing) and the 2025 first printing are still online. Search results often surface them ahead of the current second printing.
Which code applies to your application
Denver's transition policy (25-DCBC 131.2, effective December 1, 2025) draws a hard line:
- Complete construction documents first submitted on or before December 31, 2025 could still be designed to the 2022 Denver Building Code.
- Anything first submitted after December 31, 2025 must be designed to the 2025 code. There are no extensions and no "major project" exceptions.
- A 2022-code package that was rejected as incomplete and resubmitted after December 31, 2025 must comply with the 2025 code in its entirety.
- Resubmittals, revisions, deferred submittals and modified drawings for projects already accepted under the 2019 or 2022 code can stay on that code.
- Phased projects for one building can continue under the code of the first phase. Utility, site, excavation and shoring work does not count as a first phase. Separate buildings submitted after December 31, 2025 must use the 2025 code, even within the same project.
- Type-approved (master plan) applications received after December 31, 2025 must use a 2025-compliant master.
Application expiration: a 2025-code application expires if no building permit is issued within 550 days (18 months) after the City Council enacts a later IBC edition. Denver does not expect that before late 2027, so 2025-code applications would expire in mid-2029 at the earliest.
Denver amendments that change design early
- Snow loads. The 2025 code moves to ASCE 7-22 reliability-targeted ground snow loads, which vary by risk category and location. Take values from the ASCE Hazard Tool. Drawings must now show both the strength-level ground snow load (pg) and the allowable-stress value (pg(asd) = 0.7 pg). See Denver's snow load changes summary (PDF).
- Wind. Denver amends wind criteria in its building code, so use the Denver value rather than the ASCE Hazard Tool or a generic Colorado figure.
- Uncovered parking decks. Denver adds a specific combined snow and live-load provision for uncovered passenger-vehicle parking decks.
- Solar-ready zones. The structural amendments coordinate roof loading for solar-ready zones with the Denver Energy Code.
- Energy code on a different cycle. The energy code is based on the 2021 IECC while the other disciplines use the 2024 I-Codes. Record it as its own line on the code sheet. Denver publishes residential energy-code requirements and a residential electric-infrastructure policy (DEC R404.4–R404.6).
- Policies that clarify the code. Denver publishes building-code policies for the 2025 cycle, for example on setback-separation verification for one- and two-family dwellings, geotechnical reports under the residential code, A2L refrigerants and kitchen hood submittals. Check the policy list before relying on your own interpretation.
Denver's 2025 adoption presentation (PDF) summarizes the major changes in the cycle.
Denver amendment worksheet
| Question | Project entry |
|---|---|
| First complete submittal date (before or after Dec. 31, 2025) | — |
| Design code (2022 or 2025 Denver Building Code) | — |
| 2025 second printing checked | — |
| Applicable 2024 model-code chapters | — |
| Denver replacement or added sections | — |
| Ground snow load pg and pg(asd), and wind source | — |
| Denver Energy Code (2021 IECC basis) path | — |
| Mandatory Denver Green Code provisions | — |
| Zoning, landmark, view-plane or design-review overlays | — |
| Written CPD interpretation, policy or approved modification | — |
Keep a PDF or dated link to the exact printing you used. To work through a Denver project with this guide loaded, use Add to Harth agent at the top of the page. It opens the Harth agent with this page as context.
Frequently asked questions
What building code does Denver use?
The 2025 Denver Building and Fire Code, effective December 31, 2025. It amends the 2024 International Codes (IBC, IRC, IEBC, IFC, IMC, IPC and IFGC). Use the second printing adopted November 24, 2025.
When did the 2025 Denver Building Code take effect?
Denver adopted it on June 13, 2025, and it took effect on December 31, 2025. Complete construction documents first submitted after that date must be designed to it.
What is the Denver Energy Code for 2025?
The Denver Energy Code adopted with the 2025 cycle is based on the 2021 IECC with Denver amendments. It is not on the 2024 IECC, even though the other 2025 Denver codes are based on the 2024 I-Codes.
Can a project still use the 2022 Denver Building Code?
Only if complete construction documents were first submitted on or before December 31, 2025 and accepted. Resubmittals, revisions and deferred submittals for those projects can stay on the 2022 code. New submittals cannot.
Which electrical code does Denver use?
The 2026 National Electrical Code (NFPA 70), adopted without amendment. It is the same electrical code the State of Colorado adopts.
Did Denver change snow loads in the 2025 code?
Yes. Denver moved to ASCE 7-22 reliability-targeted ground snow loads from the ASCE Hazard Tool. Construction documents must show both pg and pg(asd), where pg(asd) = 0.7 pg. Wind stays on Denver's amended criteria.
Related Denver and Colorado data
- Colorado building code adoption: statewide editions and local adoption
- Climate design data for Denver, CO: design temperatures and climate zone
- Sun path and solar angles for Denver, CO: shading and solar-ready inputs
- City building-code amendments: Austin, Seattle and other city guides
Scope and sources
Harth prepared this guide from the Denver Community Planning and Development adoption records and the amendment documents linked above. It summarizes which codes apply and when; it does not reproduce the controlling code, give a legal opinion or confirm which edition governs a particular address. Where this page and an official publication disagree, the official publication and the authority having jurisdiction control.
Authored and prepared by Harth from the linked agency records. Review scope: adoption status and source paths verified; project-specific applicability and local interpretation require AHJ confirmation.