Impact Windows vs Shutters: Insurance Credits
Updated September 2026
Impact windows and hurricane shutters protect a house the same way in a storm. They are not scored the same way by an insurer, and the difference is not what most buyers expect. The carrier does not care which one you chose. It cares whether every opening is covered, whether the product is verified, and whether an inspector signed a specific form saying so.
The form that decides the discount
Florida law, in Section 627.0629, requires insurers to give premium discounts for construction features that reduce windstorm loss. The vehicle for claiming them is the Uniform Mitigation Verification Inspection Form, OIR-B1-1802, published by the Office of Insurance Regulation. A revised version, Rev. 04/26, took effect on April 1, 2026. The form is valid for up to five years provided nothing material changes on the structure and no inaccuracies are found. It must be completed by an inspector authorized under Section 627.711(2)(a), so ask who is signing before you pay for one.
Opening protection is question 9 on the current form. The instruction is worth quoting in spirit: the inspector records the weakest form of wind-borne debris protection on the structure, across every opening in the walls and roof, including windows, doors, sliding glass doors, skylights and garage doors. Roof vents are excluded. All openings must be in good condition, and a building with openings that need replacement does not qualify for the mitigation rate differential at all, regardless of its other features.
What qualifies as impact-rated
The form’s top tier, Level A, is “verified cyclic pressure and large missile.” For windows and doors that means a product tested to the nine-pound large-missile standard; for skylights, four and a half pounds. The accepted test standards are Miami-Dade PA 201, 202 and 203; the Florida Building Code’s TAS 201, 202 and 203; ASTM E1886 with E1996; SSTD 12; and, for garage doors only, ANSI/DASMA 115. The product also has to be listed in the product-approval system of the State of Florida or of Miami-Dade County.
Notice what that list does not say. It does not say “windows” or “shutters.” Rated impact glass and rated accordion, roll-down or panel shutters can each reach Level A if they are tested to those standards and verified. Level B is a lighter missile test. Level C is plywood or OSB cut to the Florida Building Code table. Level N is protection that looks like A or B but cannot be verified. Level X is nothing at all, and Level Z is a damaged opening.
| Form level | What it means on OIR-B1-1802 |
|---|---|
| A | Verified cyclic pressure and large missile — the nine-pound test for windows and doors, four and a half pounds for skylights |
| B | A lighter missile test, verified |
| C | Plywood or OSB cut to the Florida Building Code table |
| D | Non-glazed openings: an unrated but pressure-rated solid entry door |
| N | Protection that looks like A or B but cannot be verified |
| X | No protection at all |
| Z | A damaged opening — the house does not qualify for the mitigation rate differential |
Why one unprotected opening voids the credit
The form asks for the weakest opening, not the average. A house with impact glass on every window and an original, unrated garage door is scored on the garage door. A house with rated shutters on every window and a bathroom window nobody bothered to cover is scored on that bathroom window. The current form does split glazed and non-glazed openings, so an unrated but pressure-rated solid entry door (Level D) does not drag a house down to nothing, but it does move it out of the cleanest category.
Verification is the whole game
Verified means documented. The inspector needs a photograph or a document for each attribute claimed on the form, and the product-approval number is the document that matters. In Miami-Dade, that number is the Notice of Acceptance, or NOA, issued by the county’s Product Control Section, which reviews and approves windows, exterior glazing, exterior doors, skylights, glass block, roofing and shutters for use in the county. Approvals run for five years and then must be renewed by the manufacturer, and the county keeps a searchable database of current and past approvals.
For a buyer this has a practical meaning. Impact glass usually carries its approval etched or labeled on the unit, so it is verifiable in place. Shutters are verifiable only if the panels, tracks and hardware match an approved system and the paperwork or permit survives. Shutters kept in a garage with no documentation are, on the form, protection that cannot be identified.
Permits and what they prove
Window and shutter installations in Miami-Dade are permitted work. The permit file ties the installed product to its approval number and to a final inspection, which is exactly the chain the wind-mitigation inspector wants to see. When you are under contract, ask for the permit history during the inspection period; our guide to the Florida AS IS contract and inspection period explains how to use that window. Unpermitted openings are a negotiation item, and sometimes a lender item.
The resale conversation
Sellers often ask whether impact windows “pay for themselves.” The honest answer is that the market prices three things: the premium reduction a verified Level A house earns, the convenience of not putting up shutters, and the confidence a buyer feels when the permit and NOA are in the folder. Shutters that are rated, permitted and documented get a seller most of the first item. Impact glass tends to get all three. If you are preparing a home for market, our guide to selling your home in Miami-Dade covers what to gather before listing, and our flood, windstorm and roof insurance guide explains how opening protection fits with the roof questions on the same form.
Sources
- Florida Office of Insurance Regulation, Uniform Mitigation Verification Inspection Form OIR-B1-1802 (Rev. 04/26) — https://floir.gov/docs-sf/property-casualty-libraries/product-review/all-forms/form-oir-1802-adopted-version-(no-watermark).pdf
- Florida Office of Insurance Regulation, Wind Mitigation Resources — https://floir.gov/consumers/wind-mitigation-resources
- Miami-Dade County, Product Approval (Product Control Section) — https://www.miamidade.gov/global/economy/board-and-code/product-approval.page
Frequently asked
Do hurricane shutters get the same insurance discount as impact windows?
They can. The form's top tier does not say "windows" or "shutters": rated impact glass and rated accordion, roll-down or panel shutters each reach Level A if they are tested to the accepted standards, listed in the Florida or Miami-Dade product-approval system, and verified on every opening. Shutters kept in a garage with no documentation are, on the form, protection that cannot be identified.
How long is a wind mitigation inspection valid in Florida?
Up to five years, provided nothing material changes on the structure and no inaccuracies are found. The current version of Form OIR-B1-1802, Rev. 04/26, took effect on April 1, 2026, and it must be completed by an inspector authorized under Section 627.711(2)(a).
What is a Miami-Dade NOA?
A Notice of Acceptance issued by the county's Product Control Section, which reviews and approves windows, exterior glazing, exterior doors, skylights, glass block, roofing and shutters for use in the county. Approvals run for five years and are renewed by the manufacturer; the county keeps a searchable database of current and past approvals.
Does one unprotected window void the wind mitigation credit?
The form records the weakest opening, not the average. A house with impact glass on every window and an original, unrated garage door is scored on the garage door. The current form does split glazed and non-glazed openings, so an unrated but pressure-rated solid entry door (Level D) does not drag the house to nothing, but it does move it out of the cleanest category.