Denver, CO Frost Depth & Snow Load: Frost Line Depth (2026)
Key Facts
- Frost line depth
- 36 inches below finished grade
- Code edition enforced
- 2025 Denver Building Code (2025 Denver Residential Code, Table R301.2)
- Stated twice
- Table R301.2 and Denver Commercial Building Code Section 1809.5
- Jurisdiction
- City and County of Denver: consolidated, so one figure covers everything
- Statewide code
- None. Colorado municipalities each adopt their own
Summary
Denver sets its frost line at 36 inches below finished grade, stated both in the residential design criteria table and as a flat declaration in the commercial code.
Table R301.2 CLIMATIC AND GEOGRAPHIC DESIGN CRITERIA, and footnotes, is replaced as follows: TABLE R301.2 CLIMATIC AND GEOGRAPHIC DESIGN CRITERIA — GROUND SNOW LOAD 43 psf-c; Speed (mph) 115/125/140; Topographic effects No; Special wind region Yes; Wind-borne debris zone No; SEISMIC DESIGN CATEGORY B; Weathering Severe; Frost line depth 36 inches; Termite Slight/Mod. [Denver Commercial Building Code Section 1809.5:] The frost line for the City and County of Denver is 36 inches (915 mm) below the finished grade.
Full Breakdown
Colorado has no statewide residential building code, so every municipality sets its own frost depth, and Denver sets its own at 36 inches. The figure appears twice in the 2025 Denver Building Code, which is unusual and useful: the residential code replaces the model Table R301.2 outright and fills the frost line depth cell with 36 inches, while the commercial code states it as a standalone sentence declaring the frost line for the City and County of Denver to be 36 inches below the finished grade. Because Denver is a consolidated city and county, that single figure governs the whole jurisdiction with no unincorporated remainder to check separately. Note that 36 inches is shallower than several Front Range neighbours despite Denver sitting at 5,285 feet, frost depth tracks soil and air temperature rather than elevation alone.
Violations & Fines
Footing depth is checked at the foundation inspection before concrete is placed. A footing that does not bear at or below 36 inches will not pass, and the work must be corrected before it proceeds. Denver's building department enforces this under its own code rather than a state one, so the figure does not carry over to neighbouring jurisdictions.
Frequently Asked Questions
How deep do footings have to be in Denver?
Does Colorado set a statewide frost depth?
Is the frost depth different in unincorporated parts of the county?
Sources & Official References
Other rules in Denver
Compare Denver to another location·View the Colorado frost depth & snow load overview
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