Cost of air sealing and insulation
I just read the results of this research project by the EPA. In it they air seal a home built in the late 1970’s and bring it from~ 0.93 ACHnat to 0.50 ACHnat. And they also add insulation to the attic (from R15 to R38), rim joists (from R0 to R11), and floors over the crawl space (from R0 to R11).
I’m wondering:
1) Is that type of air sealing accomplishment realistic in the real world without a deep energy retrofit?
2) What kind of cost would someone be looking at to do the air sealing, the insulation, and both combined. (I realize the variability in asking for a cost due to so many different scenarios. I’m looking for a ballpark range for a blog article I’m writing.)
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It depends entirely on the house, and the level of work that's going to be done. Sometimes you find large, easy leaks, other times there's a lot of diffuse leakage everywhere and it's hard to make much of a dent. It sounds like the EPA study was based on a really leaky house and they didn't make impressive improvements in it.
Stephen,
The work you describe is routine work for weatherization agencies, and such work is almost always cost-effective (with a payback period of 7 years or less).
Talk to your local weatherization agency; in many areas of the country, these crews do for-profit work as well as work for low-income families under the Weatherization Assistance Program -- so they may be willing to give you ballpark estimates or ranges for this type of work.