Do I Need a Permit to Replace Windows in Utah?
Quick Answer
Usually no — but yes if you change the size of the opening.
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 in Utah cities. 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
All replacement windows in Utah must meet the current energy code. For Utah's climate zone, windows typically need a U-factor of 0.30 or lower. Check the NFRC label on any window before purchasing. This applies even when no permit is required — it's a state code requirement.
Egress Windows
If you're adding a bedroom in a basement, Utah code requires an egress window with a minimum 5.7 sq ft net clear opening and a sill no higher than 44 inches above the floor. 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.