Blower Door Test

Use an Air-tightness Test to Determine Energy Efficiency

One of the tools that helps determine how much energy is being used to heat and cool a home is an air-tightness test. Building Science West uses a Blower Door Test to quickly assess how much air is leaking from a residential property during final construction stages, or after the home is finished.

The Blower Door Test provides you with an understanding of a home’s airtightness. It is no illusion, when a home fails a Blower Door Test we can use theatrical smoke to pinpoint where leaks are coming from. This process ensures your construction team has detailed information to improve the sealing of the joints, walls, windows and other components inside of the structure.

Blower Door Test

Why Build With Air Tightness In Mind?

Meet Building Code

Reduce Long-Term Energy Costs

Avoid Interior Moisture Condensation

Leave a Smaller Energy Footprint

Cash In On Energy Rebates

Build a Superior Product

Building Science West Building Testing Services

How Does the Door Blaster Test Work?


  1. A technician will mount a blower door into an exterior wall door frame.
  2. The blower door testing unit includes a computer with brass inputs and pressure sensors. One of the sensors is measuring the pressure on the outside of the home, and the other sensor is measuring air pressure on the inside. We measure industry standard pressure differential in the home using a measurement of 50 pascals.
  3. The door includes the smartest fan in the world. This fan knows how much air is moving through it. There are tubes in the middle that sense the air. The sensors gather the pressure differential. The pressure difference simulates a 20 mph wind acting on your house.
  4. Within just minutes the test is complete. The airflow is measured in CFM (cubic feet per minute) is converted into the number of times the volume of air in the home changes every hour. Numbers from the test are computed and put into a report, so you know your building’s airtightness.

Utah Code

Blower Door Test by Building Science West

Current Utah code states that new residential properties must pass airtightness of 3.5ACH@50 (which means that the air in the home will be exchanged three and a half times every hour.) Older homes from stucco tract neighborhoods, to historic Wasatch Front homes built in the early 20th century measure anywhere from 8-12ACH@50 (The air in the home will be exchanged 8-12 times every hour.)

The test is pass/fail. When you pass, you can receive a certificate of completion and homeowners can move in. If the house fails, efforts will need to be made to seal the property before a retest can occur.

Cost of Blower Door Test

Prices vary depending on the size of the property, number of homes needing tests and if you are combining multiple services. Please call for a quote.

The cost includes the time to come test your property, production of the required reports, submitting all of the required paperwork for your rebates, and following up with your office to make sure you received the payments. When combined with a Duct Test, or other Green Builder Services, you can receive a bundle discount.

Where Do Houses Most Commonly Leak?

Leaky House

  1. Rim Joist
  2. Outlets
  3. Switches
  4. Drop Ceiling instead of a dry wall ceiling
  5. Leaks to the attic
  6. Top plate and bottom plates
  7. Second story
  8. Ceiling


Seven Ways To Properly Seal a House

  1. Run a bead of caulk before setting a wall in place to seal under the bottom plate.
  2. Seal the dry wall to the framing with Sill Seal or drywall gasket, it closes gaps.
  3. Seal small spaces with a bead of caulk, windows, doors, walls or switches
  4. Air seal around recessed lights, or even better, replace recessed cans with surface-mount LEDs.
  5. Close spaces around chimneys and flues
  6. Use weather stripping around the attic hatch
  7. Tighten up around the doors and windows with caulk or weather stripping
Caulking a House

Make an appointment with an energy efficiency expert today!

See how quick you can earn your efficiency rebates.