Casper, WY Building Safety: Building Permits (2026)

The city's adopted 2024 International Residential Code, amended at Section 15.02.040, bars a building permit on any unplatted property except upon written application with complete plans showing in detail all proper approaches to street and alleys, and only after the streets, alleys and approaches are deeded to the city and accepted by a vote of the city council. Section 15.02.050 then lists the only work the city exempts from that permit requirement: a one-story detached accessory building under one hundred twenty square feet in area, measured at the maximum exterior wall dimension.

Everything larger, including the main dwelling itself, needs a permit. The parallel commercial chapter, Section 15.04.020, adds that no building permit issues without an approved site plan under the zoning title, unless the city engineer waives that requirement in writing because the necessary site improvements already exist, and that financial surety for any required off-site or on-site drainage improvements must be posted under Section 16.28.070 before the permit is issued. Chapter 15.08, the dedicated building-permits chapter, further ties issuance to completed off-site improvements in the subdivision, with Section 15.08.030 allowing a foundation permit once off-site work has begun and a full building permit only once all-weather roadways, water and sewer mains are accepted and connection fees are paid.

Community Development and the city engineer jointly administer these permit conditions, and fees for both foundation and building permits are set by city council resolution under Section 15.04.100.