List of Colorado Cities And Counties Requiring Blower Door Testing (As of 2018)

Date Published: May 16, 2018

You may have recently gone to get a building permit or certificate of occupancy and been informed that you need to have a blower door test performed. For some, this is a whole new hurdle! We are here to offer a few answers to help you along in this process. In the last year, many Colorado cities and counties have started requiring blower door testing. Some have custom requirements and others follow the international energy codes exactly. To help you determine whether you will need a blower door test, we have compiled a list of all current Colorado areas requiring blower door, a.k.a. Air Leakage Testing.

List of Areas Requiring Blower Door Testing:

Although the above map above is older, it shows which counties are enforcing IECC 2012. (Colorado Department of Local Affairs) IECC 2012 (and the newer 2015 code) is when the air leakage requirements were implemented, so this list will give you a good idea whether you need a blower door test. In Colorado, there is no single state requirement. Each city or county has the option to enforce its own energy code, which determines whether or not the air leakage test is required. Below is a list of known municipalities where the tests are required, or where we have been actively testing for builders:

  • Larimer County
  • Fort Collins (Multi-Point Test)
  • Loveland
  • Boulder County
  • City of Boulder
  • Denver (city/county)
  • Castle Rock  
  • Aurora
  • Broomfield city/county
  • Commerce City
  • Federal Heights
  • Thornton  
  • Lafayette
  • Longmont
  • Louisville
  • Superior
  • Golden
  • Littleton
  • Wheat Ridge
  • Evans
  • Greeley
  • Frederick
  • Colorado Springs

Looking for our blower door testing service page? Click here.

You may need to know, what exactly is blower door testing?

A blower door test measures the exact air-tightness of a home. Our inspectors insert a flexible panel into an exterior doorway, into which we then mount a very powerful, variable-speed fan. The fan blows air out of the house which lowers the inside air pressure.

This allows the higher outside air pressure to flow in through any unsealed cracks and openings. We measure the pressure difference between the inside and outside air pressure and determine the number of air changes per hour (ACH).

Why do I all of a sudden have to get a blower door test?

IECC or International Energy Conservation Code, is a code which sets the guidelines for up-to-date energy conservation and efficiency. This code is updated every three years, and while some states (like Texas) make a statewide decision as to what energy code they will follow, we in Colorado decide on a city by city basis. Boulder, which is usually on the forefront of energy efficiency, has had stricter building codes than most other cities. This past year, the city of Denver, and several other cities updated their codes to comply with the 2015 IECC regulations which now require contractors to get a blower door test done at the completion of a new build project, or additions larger than 30% of the existing floor area.

How should I select a company that’s right for me?

Cost can vary a lot when looking into getting a blower door test done. While many may be tempted to just book with the most affordable option, that may not always be your best choice. Read reviews about the company, and see what others have said. Don’t be afraid to ask questions about the company you are looking to hire. Does their staff seem knowledgeable about the process? How long have they been in business? What training process have their inspectors gone through? How long does it take to get the report back, and how detailed is that report?

With a blower door test, many of the cheaper options won’t offer you details as to why you have failed and how you can move forward to pass, which is invaluable information in this process. Pick a company that is invested in its customer’s best interest and is not just out to make a quick buck. Scott Home Inspection will be your partner in the long run! We have multiple inspectors trained to perform blower door tests. We also use infrared cameras to help find air leaks when necessary to help you pass. Learn more about our Blower Door Testing Services here.

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About the Author: Chris Scott

Chris Scott is an ASHI certified home inspector with multiple years of experience in home inspections, blower door testing, duct leakage testing, and Boulder Rental License Inspections. Chris is also the Website Coordinator for Scott Home Inspection.

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