Special offer

Stop with the "windows first" please!

Home Inspector with ProStar Infrared Inspections

Okay, please listen to the following facts provided by Energy Star...

  • 1/3 of a home's energy loss comes through air leakage
  • Only 10% of that leakage happens around windows!!!!

If you house needs some efficiency improvement, try not to begin with the high dollar items (windows, siding, insulation).  First, properly seal the house from air leakage.  This is not as costly, and can be more cost-effective to notice the biggest difference in you comfort and energy bills.  To know where your leaks are, call us or another service provider using blower door and infrared technology.  You can make back our cost of service and your cost of proper air sealing in about 12-15 months on average.

After your home is properly sealed, then move to the more high dollar items.  If you do this in reverse, you may be tackling a problem you don't have, and you are not allowing your $1,000's of dollars worth of windows, insulation, siding to do their job!

If you have further questions, please free free to contact me!


CEO/Thermographer Level I

ProStar Infrared Inspections, LLC

Stephanie Edwards-Musa
thredUP.com - The Woodlands, TX
knitwit at thred UP

Hi Dusty, I think I'm about to do this on my house.  I re-insulated the attic....going for caulking the windows next.  :)  Great post.

Aug 01, 2007 04:14 PM
James Quarello
JRV Home Inspection Services, LLC - Wallingford, CT
Connecticut Home Inspector

Hi Dusty,

I agree in part about the windows. I perform energy audits and use an infrared camera as part of that service. Air leakage is a significant part of home energy loss, especially around the windows. I have seen many homes where 10% air leakage from and around windows would be a very conservative number.

New windows are a low payoff item, basically a wash. If your windows are already thermal double pane, changing them won't save you much or any money on your utility bills. If a window is bad, thermal seal is broken, then changing the window makes sense. Otherwise look to other areas of your home to save.

As far as insulation, big dollar item or not, it almost always is a good idea to add insulation. The payoff on insulation is usually very short and you will see a difference in your energy bills.

Aug 02, 2007 12:48 AM

Hi James!

Thank you for you input.  I too have seen significant leaks around windows, but nothing that can't generally be fixed with weatherstripping and caulking.  I have also saved many people lots of money because windows weren't the problem.  The 10% air leakage number comes directly from the US Department of Energy.  

On the insulation, many people just add fiberglass, and if they don't have any insulation, they will notice a difference.  However, figerglass losses its insulating properties when any kind of wind is put on it and it becomes an air filter.  So if a homeowner wants the most bang for there buck in that arena, cellulose is the way to go.  Also, one should still tighten their home first...according to the USDOE and other Energy Specialists like the Iowa Energy Center -- and those people know COLD!  :0)


Aug 02, 2007 08:30 AM
John Novak
Keller Williams Realty The Marketplace - Las Vegas, NV
Henderson, Las Vegas and Summerlin Real Estate
Interesting stat about windows and air leakage. I'm guessing most people think of windows first because they're the most visible. So if it's not windows, what are the top areas for air leakage?
Aug 19, 2007 12:35 PM
James Quarello
JRV Home Inspection Services, LLC - Wallingford, CT
Connecticut Home Inspector

I believe the the DOE number of 10% air leakage from windows would be derived from the fact that the outside wall area of an average home consist of about 10-15% windows and doors. Probablly the most air leakage is from the rim joist and box plate into the living space.

 This infrared photo is from a home that was about 5 years old. Notice the air leakage at the floor base and also around the windows. As you can see the air leakage from the rim joist is much more significant than from the windows. None the less these two areas need to be addressed.





Aug 19, 2007 11:50 PM