In the land of the leaky home, builders must plug the gaps


As building regulations tighten up their gaps related to energy efficiency, builders are increasingly required to tighten up their gaps, too.

That is, the gaps between walls and windows, foundations and sills, and anywhere else heat energy can be lost to the outdoors. And fixing leaks is a task that's fairly straightforward.

"B.C. has the not-so-distinct honour of having the leakiest new construction in Canada, almost twice the national average," says Doug Overholt, Program Representative for Power Smart New Homes. "So obviously it's something that with some attention can be corrected easily and without great expense.

"It's not like you're having to buy something more, or get a higher quality product to add to your builds. You just have to do what you're doing a little better."

The challenge, says Overholt, is to be able to reduce leaks consistently, in each new home you build, so it becomes a cost-efficient part of your building process.

Overholt points out that B.C.'s building code actually already requires that the "air barrier must be complete and continuous across the boundary of the building" – it's just not a clause that is currently enforced.

That will change. The new Code update is expected to include mandatory air leakage testing, with performance minimums expected to follow. Air leakage standards are already included in programs such as ENERGY STAR® qualified homes, and analysis done by the City of Vancouver found that fixing leaks is the easiest and most cost-effective way to improve an EnerGuide rating by several points.

So what do you do about it?

Where, how, and who – then test

The key to improving air sealing is to develop a systematic approach, says Overholt. Here are his suggestions.

  1. Where: Create an air leakage plan

    The first step is to identify where you are likely to have leaks. "Look over your house plans, and figure out your potential trouble spots," says Overholt. "Anywhere you have intersections – where the floor meets the wall, where the ceiling meets the pot light – those are clear places to start."
  2. How: Materials and approach

    Once you've identified potential leaks, figure out what products or methods provide the best approach to sealing them. "Spray foam, caulk, maybe a change in how you join two components. You may need to experiment a bit to find your easiest and most reliable fix," says Overholt.
  3. Who: Assign responsibility

    "Identify who is the responsible tradesperson to handle each of the fixes you've designed, and make this part of their job," says Overholt. "This is important if you want to make this easy over time. What it really means is that builders need to educate and involve all their related sub-trades – framers, insulaters, electrical, mechanical, utilities, and finishers of various types."
  4. Test before you finish

    "The easiest way to confirm the execution of your plan is with a mid-construction air leakage test," says Overholt. "You get a chance to see where leaks remain, and do additional work if necessary before they're out of reach. It's a good way to learn as you go – and educate your tradespeople too." Your certified energy advisor can provide advice about how to improve your leak sealing planning and process.

The goal is to fix leaks, and reliably prevent them in future builds.

"I expect in the next few years there will be penalties, or permits withheld, for homes that don't reach a certain standard of air tightness," says Overholt. "If you're not already engaged in this in some respect, you need to do something now to educate yourself so it's not a scramble once the Code changes are in place and everyone is trying to do it.

"We've seen builders who've been doing this over the course of the last two-three years who are now able to consistently achieve reduced air leakage without a lot of expense. In other words, they've built it into their standard construction practice."