A woman is installing the red fabric part of a blower door test in the doorway of a living room.

You’re planning to move to the great state of Florida soon, and you’re having a new home built there. Before construction is complete, you wonder if you have to schedule a blower door test to detect air leakages. Is a blower door test mandated in Florida, or are you okay going without?

Since July 1st, 2017, any new construction of residential property in Florida must undergo a blower door test to ensure the home is up to the current energy code. This change is part of the Florida Building Code, 6th Edition, and is outlined in Section 402.4.1.2.

If you want to learn even more about the blower door testing requirements in Florida, you’ve come to the right place. In this informative guide, we’ll first explain blower door tests, how they work, and who can administer them in the state. Then we’ll discuss the Florida Building Code in more detail and what the results of a blower door test mean. 

Blower Door Tests 101: How the Tests Work

Let’s begin with an explanation of blower door testing and why it’s done. A blower door test is a means of determining the airtightness of a home, often a new construction home. The blower door itself is a type of fan that goes over one of your home’s exterior doors. The fan will suck out air from the house, bringing down the pressure as it does.

The changes in air pressure cause the outdoor air to pass through any openings in the home. If yours is an uncalibrated blower door test, then the extent of your test results will be to reveal that your home has leaks. With a calibrated blower door test, the auditor can determine the quality of any prior air sealing as well as just how much air is leaking.

We’ve written up a more extensive article on the details and benefits of why blower door tests are so critical to efficiency. You can check it out here.

Who Can Perform a Blower Door Test in Florida?

So, who is qualified to perform a blower door test? According to Florida Building.org, the rules are as follows: “Per the Florida Statutes referenced in Section R402.4.1.2, individuals qualified to provide air leakage testing include energy auditors, energy raters, Class A or B air-conditioning contractors and mechanical contractors, plus approved third parties. For the purposes of this code section, an approved third party is an individual approved by a code official to perform air leakage testing.”

A picture of the blower door test control modules on the floor. The picture shows the red doorway fabric with the fan on it in the background, and the modules with a green hose coming off of it laying on a hardwood floor.

Okay, so that explains approved third parties, but what about those other listed professionals? An energy auditor is sometimes referred to as an energy rater. Their job is to determine how efficient a commercial building and/or residential property is.

Do You Need a Blower Door Test in Florida?

In 2017, the 6th edition of the Florida Building Code updated its requirements. Per what was printed in the new building code, from July 1st, 2017 onward, any new residential home that’s built in the state of Florida now requires a blower door test.

The home must also pass the test. We’ll talk about this a lot more in the next section, but a passing grade per the new Florida Building Code rules is 7 air changes an hour (7 ACH50) or fewer.

This rule is found in Section 402.4.1.2 in the Florida Building Code called Testing option, which you can review here.

Here is what the section says in full: “Building envelope tightness and insulation installation shall be considered acceptable when tested air leakage is less than seven air changes per hour (ACH) when tested with a blower door at a pressure of 50 pascals (1 psf). Testing shall occur after rough in and after installation of penetrations of the building envelope, including penetrations for utilities, plumbing, electrical, ventilation and combustion appliances.

During testing:

  1. Exterior windows and doors, fireplace and stove doors shall be closed, but not sealed;
  2. Dampers shall be closed, but not sealed, including exhaust, intake, makeup air, backdraft and flue dampers;
  3. Interior doors shall be open;
  4. Exterior openings for continuous ventilation systems and heat recovery ventilators shall be closed and sealed;
  5. Heating and cooling system(s) shall be turned off;
  6. HVAC ducts shall not be sealed; and
  7. Supply and return registers shall not be sealed.”

This is still the most current edition of the Florida Building Code as of this writing, and it applies not just in specific cities, towns, or counties, but statewide.

Exceptions to the Rule

There is one alternative to the specified blower door test from the document linked above. It’s a rigorous visual inspection with an entire table (table 402.4.2) of requirements that have to be verified by a party approved by the code official.

There are also some exclusions about who in Florida might require blower door tests. Here are the two exceptions:

  • “Section R402.4 states that dwelling units of R-2 Occupancies and multiple attached single family dwellings are permitted to comply with Section C402.5 of the commercial provisions of the Florida Energy Code. Section C402.5 allows thermal envelope leakage compliance via either a list of prescriptive requirements or through air leakage testing.
  • Section R402.4.1.2 lifts the testing requirement for additions, alterations, renovations or repairs to an existing home’s building thermal envelope if the new construction is less than 85 percent of the thermal envelope.”

Failing the Blower Door Test Will Cost You

You’re eager for your new construction home in Florida to pass its blower door test. Leesburg, Florida news resource Daily Commercial said in a 2017 article that if your home doesn’t pass, you might have to get mechanical ventilation for the home, which will improve the air quality.

Although mechanical ventilation will make it easier to breathe, both literally and figuratively, that peace of mind comes at a price. Fixr quotes the cost of a mechanical ventilation system at $500 to $8,000. Then you have to pay for installation, which might cost between $50 and $150 an hour. Adding that up, the installation costs could run $1,200 to over $8,500.

How Do You Pass a Blower Door Test?

So, how does your house pass a blower door test? Per Florida Building.org, the rules are as follows: “The building or dwelling unit shall be tested and verified as having an air leakage rate not exceeding seven air changes per hour in Climate Zones 1 and 2, and three air changes per hour in Climate Zones 3 through 8.”

In Table 402.4.2, Air Barrier and Insulation Inspection Component Criteria, here is what’s required of you to pass a blower door test in Florida.

  • Fireplaces: Your fireplace must have an air barrier.
  • HVAC register boots: Any HVAC register boots that penetrate the building envelope must be sealed to either the drywall or the subfloor.
  • Common wall: The common wall(s) between any dwelling units require air barrier installation.
  • Exterior wall phone/electrical box: For exterior walls with a phone or electrical box, you have two options. You can either get air-sealed boxes or ensure that the current air barrier goes beyond the boxes.
  • Exterior wall tub or shower: A tub or shower installed on an exterior wall requires an air barrier between the fixture and the exterior wall.
  • Wiring and plumbing: All wiring and piping need some form of insulation, be that blown or sprayed insulation or batt insulation. The insulation should be installed around the plumbing or wiring and beyond.
  • Recessed lighting: If your recessed lighting fixtures are not installed in a conditioned space, then they must be sealed to the drywall. The fixtures must also have an Insulation Contact (IC) rating.
  • Garage separation: The space between conditioned spaces and your garage must have air sealing.
  • Narrow cavities: Any narrow cavities in the new home construction must have blown insulation, spray insulation, or batts.
  • Penetrations and shafts: From flue shafts to knee walls, utility penetrations, and duct shafts, if these are around an unconditioned or exterior space and they’re open, they have to be sealed.
  • Crawl space walls: The crawl space walls must have permanent insulation. If there’s any exposed earth around the crawl space, it must have a Class I vapor retarder. You also have to tape up any overlapping joints.
  • Floors: All floors, especially cantilevered and above-garage floors, must have insulation such that the subfloor decking’s underside makes contact with the insulation. If the insulation has any exposed edges, then an air barrier must be placed.
  • Rim joists: All rim joists must have an air barrier and be insulated.
  • Doors and windows: Any space from the frame to the door jamb or window must be sealed.
  • Walls: The sill plate and foundation junction must be sealed and all headers and corners should have insulation.
  • Attic and ceilings: Drop-down stairs, knee wall doors, and attics (except for unvented attics) need sealing. Soffits and drop ceilings should have an air barrier that’s aligned with the insulation. All gaps in these areas must be sealed.
  • Thermal barrier and air barrier: An air barrier’s air-permeable insulation cannot be used to seal a space, but it can go inside an air barrier. If the air barrier is broken in any way, it must be repaired or filled. The exterior thermal envelope insulation used for any frame walls and the building envelope air barrier must be aligned and in contact. 


Since 2017, blower door tests have been a requirement for those in Florida who are pursuing new home construction. We hope this guide has proven the importance of blower door testing so you can prioritize getting yours done!

Leave a Reply

Your email address will not be published. Required fields are marked *