Building Code

Impact Windows and Building Permits

Key information about building permit requirements for installing impact windows in Florida.




February 8, 2021

Do I need to pull a permit if I am only changing one window in my house and installing an impact window? Do I need to pull a permit even though I am not changing the location or the size of the opening? We have several clients asking these questions when they are thinking about replacing one or more of their existing windows. The answer is yes, you must pull a permit if you are replacing any exterior window or door.

Impact Windows and Wind Engineering
The Florida Building Code requires you to obtain a building permit to replace an existing window for an impact window (this rule also applies if you install a non-impact window). To obtain the building permit, you will need a wind engineering report, specifying what the wind loads are for each opening in the house. The impact window or door that you are purchasing MUST have a design pressure that exceeds the wind loads calculated by the engineer. Otherwise, installing impact windows and doors is pointless.

Do Impact Windows Have Different Ratings?
The impact windows that we install in Miami must have the Miami-Dade County Notice of Acceptance, or NOA. To check impact windows ratings, you could review the NOA of the specific window or door. NOAs will have a table showing the corresponding maximum design pressures for an impact window depending on the size and glazing makeup option used. So, properly evaluating whether or not an impact window meets all the requirements is not so simple.  Important factors must be evaluated.

Where can I get the NOAs of a window or door?
Miami-Dade County NOAs can be found at county's product control Website at On this website, which is not very user friendly and is outdated in terms of user experience and navigation, you can search all of the approved products. Windows and doors are just ones of the many product categories. For hurricane impact windows and doors, you can start by choosing the Applicant under the 6 filter categories they offer.