Do I Need a Permit to Replace Windows in Utah?
Quick Answer
Usually no — but yes if you change the size of the opening.
Utah-specific rules
Adopted code: 2021 IRC and 2021 IECC, adopted statewide under Utah Code § 15A-2-103 and in force through June 30, 2026. Effective July 1, 2026 the 2024 IECC takes effect statewide while the IRC stays at the 2021 edition. Residential energy provisions are modified by statewide amendments, and some jurisdictions document residential energy at the 2015 IECC level — confirm the applicable edition locally.
Sources: Utah State Construction and Fire Codes Act (Title 15A)
When You Don't Need a Permit
Like-for-like window replacements — where the new window fits the exact same rough opening — typically do not require a building permit. This covers most standard window replacements where you are upgrading the glass, frame material, or energy efficiency without altering the wall structure.
When You Do Need a Permit
A permit is required when you change the size of a window opening (larger or smaller), add a new window where one didn't exist, convert a window to a door or vice versa, or install egress windows for basement bedrooms. These changes involve structural modifications (headers, jack studs) that must be inspected.
Energy Code Requirements
Replacement windows generally must meet the locally adopted energy code — most jurisdictions follow the IECC. Check the NFRC label on any window before purchasing and confirm your local edition's window U-factor requirement. This applies even when no permit is required — it's a code requirement.
Egress Windows
If you're adding a bedroom in a basement, most jurisdictions require an egress window with a minimum 5.7 sq ft net clear opening and a sill no higher than 44 inches above the floor (the IRC standard). Window wells deeper than 44 inches need a permanently attached ladder or steps. This always requires a permit.
Bottom Line
Swapping windows in the same opening? No permit needed. Changing the opening size or adding egress windows? Get a permit.