How Aurora Handles Frost Depth & Snow Load: A Practical Guide
Aurora maintains 156 local ordinances across all categories, and 3 of those deal specifically with frost depth & snow load. Here is a breakdown of what the city actually requires, what is prohibited, and where Aurora falls on the strict-to-permissive spectrum compared to other cities.
Frost Line Depth
Aurora requires a minimum frost depth of 36 inches for foundations, published by the city's Building Division in its Engineering Design Criteria for the 2021 I-Codes.
Key details: Minimum frost depth for foundations: 36 inches. Code edition enforced: 2021 I-Codes. Weathering: Severe. Winter design temperature: 1°F. Source document: Aurora Building Division, Engineering Design Criteria.
Footing depth is verified at the foundation inspection before concrete is placed. A foundation bearing above 36 inches will not pass. Because the criteria sheet is issued by the Building Division rather than buried in the code text, it is the document plan reviewers work from, and matching it is the practical test.
Ground Snow Load
Aurora sets a ground snow load of 40 pounds per square foot, and requires the roof snow load to be calculated from it rather than published as a fixed figure.
Key details: Ground snow load (Pg): 40 psf. Roof snow load: Not fixed: calculate per ASCE 7-16 chapter 7. Pergolas: 20 psf. Wind speed: 105-110 mph Risk Category II, with linear interpolation permitted. Special wind region: No; topographic effects No.
Ground snow load is a design input checked at plan review rather than a citable offence. Structural drawings must show the roof designed from the 40 psf ground load through the ASCE 7-16 chapter 7 calculation. Submitting the ground figure as though it were the roof design load, or using the 20 psf pergola value on anything other than a pergola, are the errors this sheet is written to prevent.
Building Design Criteria
Aurora's design criteria sheet sets seismic category B, Severe weathering, a 1°F winter design temperature and, unlike neighbouring Denver, requires ice barrier underlayment.
Key details: Seismic design category (IRC): B. Weathering: Severe. Winter design temperature: 1°F. Ice barrier underlayment: Required. Exposure category: Site-specific: per IRC R301.2.1.4 or IBC 1609.4.3.
These criteria are enforced at plan review and inspection rather than as offences in themselves. The ice barrier requirement is the one that most often surfaces late, because it is a roofing detail rather than a structural number and is easy to omit when reusing drawings prepared for a neighbouring jurisdiction that does not require it.
The Bottom Line
Aurora's frost depth & snow load rules are a mixed bag. Some areas are strict, others are relaxed, and the details matter. The best approach is to check the specific rule that applies to your situation rather than assuming Aurora is broadly strict or permissive.
Keep in mind that Aurora can amend these rules at any council meeting. For the most current version of any rule mentioned here, check the specific ordinance page, where we track updates as they happen.