Do You Need a Permit to Replace Windows?

Usually exempt from a permit

• Like-for-like replacement — new window in the exact same size opening, same location, with no change to the framing or structural opening, is permit-exempt in most states under IRC §R105.2.

Usually needs a permit

• Enlarging or resizing the opening — any change to the structural opening requires review.
• Bedroom egress windows — code-required escape/rescue openings almost always trigger a permit and inspection.
• Historic districts — a design review board typically has to approve the replacement window's appearance.
• Hurricane and high-wind zones — installing impact-rated glass often requires permit sign-off verifying the product approval.
• Cold-climate energy code checks — some states require a permit even for an in-kind swap so the inspector can verify the new window's U-factor meets the energy code.
• Anywhere in Florida, California, Oregon, Washington, New Jersey, or New York City — these require a permit for window replacement regardless of size match.

Why the exemption exists — and why some states opt out of it

The model code's logic is that swapping a window into an opening that isn't changing doesn't touch the structure, so it doesn't need the same inspection as new construction. States and cities that require a permit anyway usually do it for one of two reasons: energy-code verification (confirming the new window actually meets the state's efficiency standard) or hazard mitigation (confirming hurricane or seismic-rated glass is correctly specified for the zone). Florida and California, both high-exposure states, require it for exactly those reasons.

Who pulls the permit?

A licensed window installer will typically pull the permit as part of the job when one is required, and build the fee into your quote. Confirm this is included before signing, and ask for the permit number once it's issued so you can verify it's active with your local building department.

Pro tip from our network contractors

If you're not sure whether your replacement counts as "like-for-like," measure the existing rough opening and compare it to the new window's exact dimensions — even a small change to fit a different window line can turn an exempt swap into one that needs a permit.

What skipping a required permit risks

Unpermitted window work that should have had a permit is a common finding during a home sale inspection and can delay or complicate closing. In hurricane and high-wind zones especially, unpermitted glass that wasn't verified as impact-rated can also affect an insurance claim after storm damage. If you're unsure, a quick call to your local building department is faster than guessing wrong.