The Real Cost of Air Leakage in Your Commercial Building – CK Building Analytics Corp – A Commitment to Innovation and Sustainability

Your building’s walls, roof, and windows aren’t just losing heat through conduction — they’re leaking conditioned air straight outside. In most commercial buildings, air leakage is responsible for 25% or more of total heat loss, and in Alberta’s climate, that translates directly into thousands of dollars in wasted energy every year.

Unlike insulation deficiencies or thermal bridging, air leakage is almost entirely invisible. You won’t see it, you probably won’t feel it, and your HVAC system will quietly compensate for it — by working harder and costing more. Here’s what building owners and managers need to know.

What air leakage actually is — and why it matters more than you think

Air leakage is uncontrolled airflow through gaps, cracks, and openings in the building envelope. It’s different from ventilation, which is intentional and managed by your mechanical systems. Air leakage bypasses those systems entirely.

When warm air escapes through the envelope in winter, your heating system has to condition replacement air from scratch. In Edmonton, where outdoor temperatures routinely sit below -20°C for weeks at a time, heating that incoming air from -20°C to +21°C is expensive — and it happens 24 hours a day, whether the building is occupied or not.

According to Natural Resources Canada, space heating accounts for 53% of all energy consumed in Canadian commercial and institutional buildings. Air leakage feeds directly into that number. In older buildings with poor air barrier continuity, infiltration can account for 25% to 40% of heating and cooling energy — making it one of the single largest drivers of energy waste in the commercial sector.

How much is it actually costing you?

Let’s put some numbers to it. Consider a 5,000 m² commercial building in Edmonton with moderate air leakage — nothing dramatic, just the kind of gaps that accumulate over decades at window frames, roof-wall junctions, and service penetrations.

With Alberta commercial natural gas rates running roughly $3 to $5 per gigajoule all-in, and electricity between $0.10 and $0.19 per kilowatt-hour, a building losing 25% of its heating energy to air leakage could easily be spending $15,000 to $30,000 per year more than it should on heating alone — depending on building type, occupancy, and vintage.

But the energy bill is only part of the cost:

HVAC wear and tear. Your heating and cooling equipment runs longer and harder to compensate for air leakage. That means more frequent maintenance, shorter equipment life, and earlier replacement — capital costs that rarely get attributed to the envelope.
Comfort complaints. Drafts, cold spots near exterior walls, and uneven temperatures across floors are classic symptoms of air leakage. They drive occupant complaints, reduce productivity, and in multi-tenant buildings, they affect retention.
Moisture and durability. When warm, humid interior air leaks outward through the envelope in winter, it hits the dew point inside the wall assembly. The result is condensation, wet insulation, mold growth, and long-term structural damage. We regularly see buildings where air leakage has been silently degrading wall assemblies for years before anyone notices.

Where the leaks hide

Air doesn’t leak evenly across the building envelope. It concentrates at transitions, penetrations, and interfaces — the places where different materials and assemblies meet. The most common culprits in commercial buildings include:

Roof-to-wall junctions — where the roofing membrane meets the wall air barrier. This is one of the most common failure points, especially in buildings where the roof and walls were built by different trades with no coordination of the air barrier transition.
Window and door frames — gaps between the frame and the rough opening, failed sealants, and deteriorated weatherstripping.
Service penetrations — every pipe, duct, conduit, and cable that passes through the envelope creates an opening. In a typical commercial building, there are hundreds of these.
Floor-to-wall connections — particularly at grade level, where the foundation meets the above-grade wall, and at each floor slab in multi-storey construction.
Vestibule and loading dock areas — high-traffic openings with complex framing and frequent mechanical damage.
Parapet walls — the transition from exterior wall to parapet often has incomplete or disconnected air barrier continuity.

Individually, each gap might seem minor. Collectively, they can add up to the equivalent of leaving a window open year-round.

How we find them

Air leakage paths are invisible under normal conditions, but they become clearly visible with the right tools. At CK Analytics, we use drone-based infrared thermography to map the thermal signature of your entire building envelope.

During cold weather — and Alberta gives us plenty of that — air leakage shows up as distinctive thermal patterns on the building’s exterior surface. Warm air escaping through a gap creates a localized hot spot that stands out sharply against the surrounding cold envelope. Our aerial thermal surveys capture every wall face and roofline in a single pass, producing a complete map of leakage locations.

For the most detailed results, thermal imaging is combined with pressurization testing. A blower door system creates an artificial pressure difference across the envelope, which amplifies leakage through defects and makes them easier to detect and quantify. This combined approach — pressurization plus infrared — is the standard method referenced in ASTM E1186 for air leakage site detection.

The output is straightforward: a visual record of every significant air leakage path in the building, prioritized by severity, with clear locations for remediation.

What the building codes say

Canadian building codes have been steadily tightening requirements around air barriers, and the direction is clear — airtightness is becoming a compliance issue, not just a performance one.

The National Energy Code of Canada for Buildings (NECB) 2020 introduced provisions for whole-building airtightness testing in accordance with ASTM E3158, with a target leakage rate of 1.5 L/(s·m²) at 75 Pa. While this testing remains optional in the current code cycle, it signals where the code is heading.

For context, the National Research Council’s database of tested Canadian commercial buildings shows an average leakage rate of 2.93 L/(s·m²) at 75 Pa, with individual results ranging from 0.20 to over 19. That means the average Canadian commercial building leaks roughly twice the NECB target — and many are far worse.

Modelling by NRC shows what reaching the 1.5 target could save across different building types:

Warehouses: 31% average annual energy savings
Primary schools: 10% average annual energy savings
Large offices: 9% average annual energy savings
High-rise residential: 5% average annual energy savings

Alberta adopted Tier 1 of NECB 2020 in May 2024. As the province moves through future code cycles, mandatory airtightness testing for new construction is a realistic expectation. Building owners who understand their current leakage performance will be better positioned when that happens.

Programs that can help with the cost

Several programs currently support envelope improvements in Alberta:

Municipal Climate Change Action Centre (MCCAC) — Community Energy Conservation Program: provides up to $500,000 per municipality for energy audits and retrofits in municipally owned facilities, including envelope upgrades. Applications are open through April 30, 2026, or until funding is depleted.
Clean Energy Improvement Program (CEIP): Alberta’s property-assessed financing tool for energy efficiency upgrades. Calgary approved a commercial CEIP bylaw in April 2025, with the program expected to launch in 2026. This allows building owners to finance envelope improvements through their property tax bill, with no upfront capital required.
Canada Green Buildings Strategy: the federal government’s $150-million framework targeting deep retrofits in commercial, institutional, and residential buildings. Related programs like the Deep Retrofit Accelerator Initiative ($185.5 million through March 2027) fund organizations that help building owners plan and execute major envelope upgrades.

Funding programs change frequently — some open and close within months. The important thing is to have your building’s performance data ready. An energy audit or thermal inspection gives you the documentation these programs require for applications.

Monitoring after the fix

Sealing air leakage paths is only valuable if the improvements hold. Building envelopes are dynamic — sealants degrade, mechanical damage occurs, and building movement opens new gaps over time. That’s where continuous energy monitoring comes in.

By installing sensors that track temperature, humidity, and energy consumption at key points in the building, you can detect when envelope performance starts to slip — before it shows up as a spike in your utility bills. A sudden change in heating energy consumption during a cold snap, for example, might indicate that a repaired air barrier joint has failed.

Monitoring also gives you the data to verify that your retrofit actually delivered the savings you expected. Instead of comparing year-over-year utility bills and hoping the weather was similar, you have continuous, weather-normalized performance data that proves the return on your investment.

Start with a baseline

If you don’t know where your building is leaking, you’re paying for heat that never reaches your occupants. A drone-based thermal inspection gives you a complete picture of your envelope’s airtightness performance — every wall, every roof section, every transition detail — in a single survey.

From there, you have what you need to prioritize repairs, apply for available funding, and make decisions based on measured data rather than assumptions.