How to incentivize a builder for careful air sealing?
So we haven’t hired the builder of our future house yet, and are trying to figure out how to ensure that air sealing is a priority for the builder as well as for us. Certainly, we will specify what we can, and will choose someone with a good reputation and an apparent commitment to quality work. Still, the best plans depend on execution, and not everyone thinks of 4 ACH 50 as a bad score. It seems that 2 ACH 50 should be a good result and reasonably achievable, but how do I get a builder to really try to achieve it?
Having a test done at least once during construction, before walls are drywalled, sounds like a no-brainer (the air barrier is supposed to be at the exterior sheathing layer). But what should our expectations be at that point?
What about a blower door bonus at completion? How much of a bonus?
Other suggestions?
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Replies
Simply state the ACH desired in your contract and hire a contractor who has already achieved such in many prior builds.
Ian,
It all starts with a good set of plans from your Architect or Designer. Those plans should have every single detail on the Energy Star’s Thermal Enclosure Checklist (See attachments) that applies to your home design. Then, as AJ suggests, make sure this issue is included in the contract and hire a contractor that has experience in building Energy Efficient homes; and finally, make sure you hire a HERS Rater to do an inspection and possible testing.
It really its not a hard job, but it requires a home builder that is diligent and detailed in his/her work, and good at following up the plan detailing. I was taught a good lesson many years a go: “you build what you inspect and not what you expect”
I'm with the others, hire a builder who specializes in energy efficient construction. Set a target of say, 1.5 ach50 and do not settle for less.
Trying to get a builder to build airtight who has not done so before will be a challenge, the best builders are already up to speed and a low ach50 is part of their package.
Ian,
There are further benefits to hiring a builder who specializes in EE projects vs one who has not done a EE project yet: It's kind of safe to say that a builder who has already made a step into building projects with low leakage rates inherently has gained additional knowledge and skills in the process. Consider it a more up to date "building envelop library" and an improved understanding of the other important aspects of ventilation, passive solar utilization and low energy fixtures.
Builders get this kind of knowledge because they seek it out. those that do are at the top of their game.