Air tight buildings and insurance claims – Responsibility for restoring ACH?
I’m speculating about what might happen in 20 to 30 years. I live in British Columbia, Canada, where we are making great progress on energy efficient buildings. That said, we have a bit of a sordid history up here of great ideas becoming problems down the road (leaky condo crisis, poly-b piping, etc.) I’m not in the industry but I’m looking at how these things are being put together (with the vapor barrier on the interior side up here) and I’m wondering if they are going to be a nightmare in the future when they need to be renovated or repaired.
For projects like re-piping, replacing windows, repairing roofs and decks, etc. it seems like there will be a lot of opportunities to reduce the air tightness of the building. Do you anticipate a future where contractors that perform repairs/renovations (particularly repairs for claims made under insurance for water leaks, etc.) will be obligated to do a blower test and to ensure the old ACH rating is attained?
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Does your code mandate a certain tightness level like the IRC? Technically all modifications have to maintain code. The question is whether it will be enforced. If insurance was paying to repair my house I would flip out if they tried to do something not to code.
But you raise a good point. I was talking to a friend for mine who's a mechanical engineer, and I asked him why they always put their thumbs on the scale to increase the heating load in the Manual J. His response: "What about in ten years when the house isn't tight any more?"
That's a good point about code. I think one challenge will be in cases where the building was built to be above-code.
Canada_Deck,
I don't know the answer, but it is something I worry about with the proliferation of different approaches to air-sealing. Whatever its shortcomings, the universal use of interior poly in Canada has meant there was a visible and easily identified air-barrier to inspect and repair. Not knowing where in the wall it is, or what material is providing that function is bound to complicate future work.
Thinking along the same lines as DC's engineer - Perhaps rather than worry too much about the deterioration of the air-barrier, it makes more sense to design building assemblies with enough resilience built in that they don't rely on perfect air-sealing not to fail?
I agree that owners often have no idea how the assembly was originally built. Perhaps as-built drawings should be legally required to be transferred to all future owners?
I also agree that systems should be resilient but unfortunately that doesn't seem to be the case in many situations.
Seems to me you don’t need to worry about the insurance companies going broke paying claims.
If and when the building begins leaking enough air that the heating systems can’t keep the set temp the smart owners will buy a caulking gun and get to work and the lazy owners will buy larger equipment to replace the ones that can no longer do the job.
Air leaks seem unlikely to damage a building to the point it becomes unlivable and if they could it will be a slow process and the owners are likely to find and make Band-Aids repairs when minor problems show themselves long before the structure is in danger.
Walta
Thanks Walter but I am talking about a different scenario. I'm thinking of the case where something happens like a pipe bursts in a wall and floods the house. An insurance claim is made and contractors are brought in. They need to cut open walls to do extensive repair work. When they are done, the job looks good but did they fully repair the vapor/air barriers? Today, I've never heard of anyone actually testing that but as buildings become more air tight, I wonder if that will become one of the things that is tested.
However, that brings up the question of: How do you prove what your ACH rating was before the repair? Do you get a test every five years so you have evidence that the repairs did not bring the building back to the original conditions?
My area requires only ACH 7. However, it does require blower door testing to get a CO. After my own EXTENSIVE work following behind contractors who did not care, the final blower door on my house is ACH 1.1. When insuring I tried explaining this to the insurance company. They have no category for it. Add to that that the insurance database is so old it won't keep up with current construction costs. I ended up insuring mine to the max they would allow, and they are required to build back to replace what is there. Code does not require hardwood floors either, but if something catastrophic happen I fully expect the insurance company to replace my solid white oak hardwoods. Same goes for my air sealing. Not required by code, but required to replace what is there...
I just really hope I never have to test this.
It's wonderful that engineers are already thinking about what will happen to the houses under construction in decades. It indicates a conscientious attitude to their work and focuses on high-quality buildings. I also like that most people are now thinking about ecology. But I want to point out that it is quite difficult to think about the environmental situation in the world given the global economic crisis. And now I'm more concerned about how much does a pool increase insurance https://www.agilerates.com/home-insurance/home-insurance-basics/will-a-pool-raise-my-home-insurance-premiums/ than the future of my house. It's sad.