Do I need a permit to replace windows or exterior doors?
It depends on the specifics
Like-for-like replacement in the same opening is sometimes exempt. Changing the opening size is structural and is not.
What changes the answer
- Same opening, same size — sometimes exempt, but many jurisdictions still require a permit for egress and energy compliance
- Enlarging or cutting a new opening — permit required, it is structural
- Bedroom windows must meet egress size requirements, which is the most commonly failed item
- Replacement glazing in hazardous locations must be safety glazing
These thresholds come from the model code and are commonly amended locally, which is usually where people get caught.
Why it matters
Undersized bedroom egress windows are a life-safety failure and one of the most common things flagged at inspection or sale.
Confirm the requirement with the authority that would issue the permit before deciding.
The version of this people actually ask
Do I need a permit for a like-for-like window replacement?
Glass replaced in an existing opening with no change to the opening is the mildest version of this and is often exempt, but the practice varies more than the code text suggests — plenty of jurisdictions permit all window replacement so that egress, safety glazing and fall protection get checked. Insert or pocket replacements that keep the existing frame are the likeliest to need nothing; full-frame replacement is the likeliest to need something.
Do I need a permit to make a window bigger or add a new one?
Yes. Changing an opening in an exterior wall cuts framing and needs a header sized for the load above, which is structural work in any jurisdiction. This is a different project from replacement and is usually priced and scheduled as one.
Do bedroom windows have to meet egress requirements when replaced?
This is the trap in the whole category. Every sleeping room needs an emergency escape and rescue opening, and the minimums are dimensional — net clear opening area, a minimum clear height and width, and a sill not too high above the floor. A replacement window installed inside an existing frame is smaller than what came out, and a bedroom window that was just barely compliant can fail after a routine replacement. Nobody notices until an inspection or a sale.
Do I need a permit to replace a sliding door with French doors?
If the rough opening does not change, it is closer to a door replacement; if it does, it is structural work on an exterior wall. Either way there are two requirements worth knowing about in advance: glazing in and near doors has to be safety glass, and an exterior door assembly in a wind-borne debris region has to be rated for it.
This is the typical rule, not your answer
This is the typical rule in the United States and not a decision about your property — permitting is run by more than 22,000 separate authorities and any of them can amend the code it adopts, so confirm with your local building department before you start. Put a ZIP in to see what applies in that state, and how to reach the office that decides.
IRC R105.2 exempts replacement of glass in an existing opening only where no structural change occurs; egress per R310.
Other projects
- Build a deckA permit is usually required once a deck is more than 200 square feet, more than 30 inches above grade, serves an exit door, or is attached to the house.
- Put up a fenceFences under 7 feet are typically exempt from a building permit — but height limits, corner-visibility rules and pool-barrier requirements are set locally and catch people constantly.
- Add a shed or small outbuildingOne-story detached sheds are typically exempt up to 200 square feet under the residential code — but the number people quote is 120, and both are right depending on which code your jurisdiction adopted.
- Replace a water heaterReplacing a water heater almost always requires a permit, even though it is routinely done without one.
- Remove or open up an interior wallIf the wall is load-bearing, a permit and engineered drawings are required. If you are not certain whether it is load-bearing, assume it is.
- Upgrade or replace an electrical panelPanel and service work always requires a permit, and in most places must be done by a licensed electrician.