MassSave Insulation Program
I recently bought an old home located near Boston, Massachusetts. The house is 3-stories and, from what I can tell, uninsulated. I’m looking to start with spray-foaming the attic, which is quite small, to get the maximum amount of insulating value from the limited space I have. Rather than open the 2×4 walls, I’m hoping to fill them with cellulose. Then, I’d like to insulate the floor joists between the basement and first floor with spray-foam.
I was hoping to use the MassSave program insulation rebate to help pay for some of the work. However, I was informed by two of their contractors that the program does not cover spray foam. I can’t find any guidance on the insulation program and am wondering if anyone has more insight into it?
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Replies
Mike,
At least one for-profit insulation contractor claims that MassSave money can be used for spray foam -- see this link:
http://www.moonworkshome.com/mass-save/mass-save-what-you-need-to-know/
The web page notes, "Mass Save® Incentives, Discounts, and Rebates: If the results of the home energy assessment show that your home is in need of repair, Moonworks can help you take advantage of certain incentives and rebates which will help defray these costs. For example, if you allow Moonworks to apply high-quality, spray foam insulation in your walls, attic, or crawl spaces, you could save 75% of the costs of the service up to $2,000. "
Of course, this information may be inaccurate.
My understanding is that they no longer subsidize foam on the underside of the roof decks (that's been true for about half a decade now), and do not subsidize basement insulation other than to insulate & air seal the foundation sill & band joists.
They DO subsidize the use of foam for air sealing (including air sealing & insulating the foundation sill & band joist.) If the house is as uninsulated as you say it is, they will very likely subsidize the air sealing, with before & after blower-door tests. DO THAT STEP FIRST! If you insulate the walls first it won't be as leaky, and you might not be leaky enough to qualify for the air sealing. Air sealing is far and away the best bang/buck for both MassSave, and you.
As of 3 years ago MassSave WOULD subsidize R49 cellulose on the attic floor and an insulated attic hatch, even if it means installing another set of joists perpendicular to the existing joists to get sufficient depth for R49. (At least that was true for a co-worker who bought a 1920s bungalow in Arlington about that time.)
>Then, I’d like to insulate the floor joists between the basement and first floor with spray-foam.
BAD idea!
If there's any plumbing in the basement insulating between the first floor & basement increases the freeze up risk pretty dramatically. If the boiler or furnace is in the basement insulating between the first floor & basement is effectively throwing away ~ 15% or more of the heat put out by the fuel, since it's isolating the distribution & jacket losses from the fully conditioned space. It's FAR better to air seal and insulate the exterior foundation walls, which will raise the temperature of the basement, pretty much eliminating the freeze-up risk, and drastically reducing the heat loss through the first floor.
Insulating the foundation can be pretty cheap & easy using reclaimed roofing foam if it's a poured concrete or CMU foundation. There are multiple vendors in the 128 -495 region selling used foam board for less than 1/3 the cost of virgin-stock goods. Even reasonably flat quarried stone foundations can be insulated with rigid foam board. If it's fieldstone it'll be a closed-cell foam at about $2.50-$3.50 per square foot, which adds up fast. The guy in Arlington eventually did his with ~3" of HFO blown 2lb foam at about $4 per square foot, with a steel studwall @ wallboard in front of it for fire protection. His was a cinder block foundation that could have been done far more cheaply as a DIY using recliamed foam, but he's not much of a DIYer.
Martin and Dana,
I appreciate your insight and advice. It sounds like my best bet is to make sure the energy auditor does a thorough audit with pre and post blower-door checks followed-up by complete air-sealing and then installation of cellulose insulation where possible.
The basic MassSave audit doesn't usually include a blower door test- you have to point out that it's air-leaky and request a follow up with a blower door. You might be able to point out ahead of time that it's super air-leaky and get it all done in the first round.
Not all air leaks carry the same weight. In a 3 story the stack effect drive is high, and air-sealing the basement walls & band joist is far more important than air-sealing the floors in between. The upper floor ceiling and any plumbing/electrical/flue chases running from basement to attic are also on the critical leakage list.