British Columbia · Energy · checked September 28, 2026

Ventilation and humidity assessments in Langley

Condensation on windows, musty basements and stuffy bedrooms are ventilation and humidity problems, and they're easy to confuse with insulation problems. A ventilation assessment measures which one you have.

Get matched in Langley → The ventilation and humidity assessment
A heat recovery ventilator on a basement wall with four insulated ducts running up between the joists

Cost

Part of an evaluation

Houses built since 2001

41%

Tighter houses that usually rely on an HRV or ERV

Houses built before 1961

4%

Older houses usually leak more and have less insulation

Winter design temperature

−6.3°C

Colder days mean more window condensation

How Langley is built

Langley's houses by when they were built Ten house shapes, one for each tenth of Langley's 42,165 houses. Before 1961: 4%, 1961–1990: 37%, 1991–2000: 18%, 2001 or later: 41%. Older houses glow hotter.
  • Before 1961 4%
  • 1961–1990 37%
  • 1991–2000 18%
  • 2001 or later 41%
Each house stands for one in ten of Langley's 42,165 houses (single-detached, semi-detached, row and duplex), drawn by when it was built. The glow shows the usual pattern: older houses tend to be leakier and less insulated. Rain marks the mild, wet winters: here moisture, not deep cold, is the main winter risk. Sources: Statistics Canada 2021 Census (table 98-10-0233-01), NRCan HOT2000 climate data.

Why Langley homes get humidity problems

Langley gets about 2,851 heating degree-days a year, a measure of how much heating its climate needs, and its winter design temperature, the cold day heating systems are sized for, is −6.3°C. Those figures come from the climate data for Pitt Meadows in HOT2000, the home-energy software Natural Resources Canada (NRCan) gives energy advisors. Mild, damp winters mean indoor humidity rarely has a chance to dry out on its own, so fans that actually vent outside matter.

Of Langley's 42,165 houses (single-detached, semi-detached, row houses and duplexes), 4% were built before 1961 and 41% before 1991, according to the 2021 Census. Newer houses (41% of Langley's were built since 2001) are tight and usually have an HRV or ERV that needs balancing and cleaning. Older houses that get air-sealed can lose the accidental ventilation they used to rely on.

Wildfire smoke reaches Langley in some summers. The Government of Canada's advice is to keep windows and doors closed, limit exhaust fans and use the best filter your system can handle, so ask the advisor what your furnace or HRV can take. An HRV or ERV brings in outdoor air, so ask the installer or check the maker's instructions for how to run yours on smoky days.

What the assessment measures

  • Relative humidity in living areas and the basement.
  • Actual airflow from bath and kitchen fans, and whether they vent outside rather than into the attic.
  • How much fresh air the house gets, and whether an HRV or ERV is balanced.

The ventilation and humidity assessment in detail.

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Coastal BC Lower Mainland and Vancouver Island

What this means in Langley’s climate

Mild, wet winters and summer heat waves: fix moisture first, then cooling and heat pumps.

Why it matters here: Checks that bath and kitchen fans vent outdoors and move enough air to control winter damp in a tighter house.

Best timing: At the same visit as the blower door test.

  • Fix moisture before tightening up. Heavy winter rain soaks walls and roofs here. Insulation makes outer layers colder and slower to dry, so fix leaks, condensation and mould first, or upgrades can trap water. Ask: Ask the registered energy advisor to note stains, damp spots and roof or window leaks, and to check that bath and kitchen fans vent outdoors.
  • Add ventilation as you tighten. A tighter house in a damp climate needs fans or an HRV to keep winter humidity down. Without them, condensation and mould can follow, and gas appliances risk backdrafting. Ask: Ask for a ventilation assessment, and a combustion safety test if you have a gas furnace, boiler, water heater or fireplace.

What else homes in Langley need →

Sources for this climate guide · checked October 26, 2026

NRCan-licensed service organizations serving Langley

A service organization is a company that Natural Resources Canada (NRCan) licenses to deliver EnerGuide evaluations; its registered energy advisors do the home visit. Advisors assess ventilation and humidity as part of an evaluation and check that exhaust fans actually vent outside. Sizing an HRV or ERV may be extra.

Source: NRCan list of licensed service organizations, checked September 28, 2026. Call to confirm your street is covered and ask about wait times.

Programs in Langley

Provincial · needs an evaluation BC Home Energy Improvement Bonus $20 for every percentage-point your home improves — $750 minimum, $2,000 maximum — or $300 for any two upgrades Open

Ventilation and humidity assessment in Langley: common questions

HRV or ERV?

Both bring in fresh air and recover heat. An ERV also transfers some moisture, which helps keep very dry winter air from getting drier; an HRV suits houses that tend to run humid.

Why did condensation appear after we got new windows?

Tighter windows cut accidental air leakage, so humidity builds up. The fix is usually controlled ventilation, not leakier windows.

Is a ventilation assessment part of an EnerGuide evaluation in Langley?

Advisors assess ventilation and humidity during the evaluation; HRV or ERV sizing may be an extra service.

Ventilation and humidity assessment near Langley

Ventilation and humidity assessment in Surrey17 kmVentilation and humidity assessment in Abbotsford21 kmVentilation and humidity assessment in Coquitlam26 kmVentilation and humidity assessment in Delta30 kmVentilation and humidity assessment in Burnaby32 km All 70 cities →

Sources

Checked September 28, 2026. Census figures are for the municipality (British Columbia); climate data is NRCan's HOT2000 station Pitt Meadows (14 km away).

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