Replacing windows or doors in Sebastian? The permit, the paperwork and the 25% impact rule

Old windows that stick, sweat or rattle in a squall are a common Sebastian complaint. So are front doors that let the rain in sideways. Replacing them is a big job, and the City of Sebastian has a one-page sheet that spells out what it wants to see first.

If your home is inside Sebastian city limits, that sheet and the city's Building Department are your starting point. Here is what it says, in plain English.

What goes in the permit application

The city's window and door replacement sheet covers one- and two-family homes under the 2023 Florida Building Code, Residential (8th Edition). It asks for three things with your permit application:

1. One copy of the product approvals for the windows or doors, with the installation instructions.
2. A sketch of the house showing where every opening is and how big it is, including the emergency escape and rescue openings (the bedroom windows someone could climb out of in a fire).
3. The U-factor and SHGC for each type of opening. Those are the energy ratings printed on the window's label.

On the city's fee list, window and door replacement is a flat $75 permit. Storm shutters are a separate flat $75 permit.

The wind rating: what 160 mph means

The city's sheet sets the design wind speed at 160 mph. From that, it lists the wind pressures a window or door has to hold, in pounds per square foot, pushing in and pulling out.

Two things change the number for your house. The first is exposure: the sheet has columns for Exposure B, C and D, and the numbers climb from B to D. The second is location on the wall: the sheet lists a Zone 4 and a Zone 5, and Zone 5, near the corners of the house, carries the higher pull-out pressure. For a 10-square-foot window on a home with a roof under 30 feet, the pull-out pressure on the sheet ranges from 30 psf in the middle of a wall in Exposure B to 61.4 psf near a corner in Exposure D.

You do not need to do this math yourself. The point is simple: the window you pick must have a product approval rated for the pressures at your house. A cheap window rated for a lower number may not pass.

Garage doors have their own table on the sheet. A 16-foot by 7-foot door, for example, is listed at 26 psf pull-out in Exposure B and 43.2 psf in Exposure D.

The 25% rule for impact protection

This is the one that surprises people. The city's sheet cites the Florida Existing Building Code, section 706.4: when more than 25% of the glazed openings in a house are replaced in any 12-month period, the replacement glazed openings must have impact protection.

So if you replace two or three windows in a house with twenty, you are under the line. If you do the whole back of the house this year and the front next spring, count carefully. The rule says any 12-month period, not just a calendar year.

Impact protection can mean impact-rated windows, or approved protection over the openings. Ask the Building Department which options it accepts for your job before you order.

Energy and safety glass rules

The sheet also points to the energy code. It lists a solar heat gain coefficient (SHGC) of 0.25 for both regular and impact-rated glass, with separate U-factor numbers for each. Glass in spots the code calls hazardous locations must meet the code's safety glazing section, R308.4. Your installer or the Building Department can tell you which openings that covers.

What to do before you order windows

1. Confirm your home is inside Sebastian city limits. If not, Indian River County handles your permit.
2. Count your windows and glass doors. Write down how many you plan to replace in the next 12 months and whether that is more than 25%.
3. Get the Florida product approval number (an FL number) for each window and door you are considering.
4. Look it up yourself on the state's Florida Building Code Online product approval search, at floridabuilding.org, by FL number or manufacturer.
5. Keep the label energy numbers (U-factor and SHGC) and the installation instructions. The city wants both.
6. Make the sketch: every opening, its size, and which ones are bedroom escape windows.
7. If you hire someone, check the license at myfloridalicense.com and have them pull the permit.
8. Apply online through the city's MGO Connect portal, by email to permits@cityofsebastian.org, or at City Hall. Owner-builders must submit the first application in person.

New windows should last for decades. A few minutes with the city's sheet now makes sure they pass inspection the first time.