Retrofit Air Sealing for Existing Homes

Most BC homes built before 2015 leak air. A lot of it. Typical older residential buildings measure 5-15 ACH50 on a blower door test, compared to the 2.5 ACH50 required for new construction under BC Step Code 3. That air leakage is why you feel drafts near windows, why your heating bill spikes in January, and why some rooms never feel comfortable.

Retrofit air sealing is the fix. Okanagan AeroBarrier Inc. delivers AeroBarrier aerosol air sealing for existing homes across the BC Interior. The same technology that achieves 0.24 ACH50 on new construction works equally well on existing homes - sometimes with dramatic results. We have seen retrofit projects drop from 10+ ACH50 down to 2-4 ACH50 in a single treatment session.

Why Retrofit Air Sealing Matters

Air leakage is usually the single biggest energy performance problem in older BC homes. More than insulation. More than windows. More than mechanical efficiency. Here is why:

• Air leaks bypass insulation. You can have R-40 attic insulation, but if air is escaping through electrical boxes, plumbing penetrations, and attic hatches, the warm air your furnace produces is going straight outside.
• Air leakage drives heat loss exponentially. On a cold, windy day, air infiltration can account for 30-40% of total heat loss in an unsealed older home.
• Leaks compound over time. Seals degrade. Caulk cracks. Old gaskets fail. The older the home, the worse the leakage typically gets.
• Comfort suffers before the bill does. Drafts, cold spots, dry indoor air in winter, dusty surfaces - all symptoms of a leaky envelope.

Energy Savings From Retrofit Air Sealing

The exact savings depend on how leaky your home started, how much it leaks afterward, and how you heat the space. As rough guidance, a home that drops from 8 ACH50 to 3 ACH50 can typically expect 15-25% lower heating bills. That is before any other efficiency upgrade. Stack air sealing with attic top-up insulation or a heat pump conversion and the savings compound significantly.

Payback periods depend on fuel costs and utility rates in your area, but for most Interior BC homes heated with natural gas or electric resistance, air sealing is among the shortest-payback upgrades available.

Comfort and Health Benefits

Energy savings are the measurable benefit. Comfort is the benefit homeowners actually notice. Retrofitted homes report:

• Warmer floors in winter, especially in rooms above unheated crawl spaces or basements
• Fewer drafts near windows, doors, and electrical outlets on exterior walls
• More even temperature from room to room
• Better humidity control in both summer and winter - tight homes hold humidity better
• Less dust because there are fewer pathways for outside air to carry particulate inside
• Quieter interiors since air gaps also carry sound

CleanBC Better Homes and Retrofit Rebates

BC homeowners doing retrofit work may qualify for several rebate programs:

• CleanBC Better Homes - the main provincial rebate program covering insulation, heat pumps, windows, and whole-home energy retrofits
• FortisBC rebates - incentives for specific air sealing and insulation measures (see our FortisBC rebates guide)
• BC Hydro rebates - for electrical heating system upgrades and heat pump retrofits
• Canada Greener Homes Grant - federal program providing up to $5,000 for eligible retrofits

These programs typically require a pre-retrofit EnerGuide evaluation and a post-retrofit re-evaluation to qualify for payment. Your energy advisor handles the evaluations. We handle the air sealing work between them.

How AeroBarrier Works for Existing Homes

The AeroBarrier process for retrofits looks similar to new construction but with some important differences:

1. Assessment. We do an initial walk-through of your home to understand the envelope, identify access challenges, and estimate expected results.
2. Pre-seal blower door test. We measure your starting airtightness so you have a baseline.
3. Masking and prep. We mask finished surfaces, HVAC registers, and any items you do not want the sealant touching. This typically takes 2-3 hours.
4. Sealant application. The home is pressurized and aerosolized sealant is sprayed into the air. Particles migrate to leaks automatically. The process runs live under a blower door so we watch the ACH number drop in real time. Typically 60-120 minutes for the seal itself.
5. Cleanup and verification. We remove masking and verify the final ACH50 measurement. A before-and-after report documents the improvement.

Total time on site for a typical existing home is 4-6 hours. The home is typically ready for re-occupancy immediately after cleanup.

What AeroBarrier Cannot Do for Existing Homes

We believe in being upfront about limitations. AeroBarrier is not a miracle product for every situation. Specifically:

• It does not replace missing insulation. If your attic is bare, you still need insulation.
• It does not fix structural envelope issues like rotten sheathing or failed siding.
• It cannot reach leaks on the exterior side of the finished wall if the leak is behind solid drywall, though it often still improves them significantly.
• It does not replace the need for HVAC upgrades if your system is undersized or poorly designed.

For most existing homes, the right strategy is AeroBarrier plus targeted traditional air sealing (attic access detailing, rim joist sealing in unfinished basements) plus insulation upgrades where needed. We can scope all of this in an initial assessment.

Service Area

Retrofit air sealing is available across the BC Interior including Kelowna, West Kelowna, Vernon, Penticton, Kamloops, Lake Country, Salmon Arm, and surrounding communities.

Frequently Asked Questions

Can AeroBarrier work on my 1970s home?

Yes. We have sealed homes from every era. Older homes often show the most dramatic improvement because they start from a much higher baseline leakage. Expect a significant drop in ACH50 after a single session.

Does AeroBarrier leave a mess inside my home?

No. We mask finished surfaces and HVAC components before spraying. The sealant is water-based and dries quickly. Once cleanup is complete, the home looks exactly as it did when we arrived.

Is the sealant safe for people and pets?

The sealant is water-based, non-toxic, and GREENGUARD Gold certified. You will need to leave the home during application (typically 2-3 hours) but can return immediately after cleanup.

How much does retrofit AeroBarrier cost?

Retrofit pricing varies based on home size, accessibility, starting leakage level, and target airtightness. Most retrofit projects fall in the $3,500-$6,000 range. CleanBC and federal retrofit rebates often offset a portion of the cost when combined with other eligible upgrades.

Do I need a blower door test first?

A pre-seal blower door test is part of our retrofit process. If you are applying for CleanBC Better Homes or Canada Greener Homes rebates, your registered energy advisor will also do their own pre- and post-retrofit EnerGuide evaluations, which include blower door testing.

Can I combine AeroBarrier with a heat pump installation?

Yes, and you should. Air sealing reduces your home's heating load, which often allows for a smaller (and cheaper) heat pump. Sequence the air sealing first, then size the heat pump based on the updated load calculation.