Canadian building code question

What are the building code requirements for air tightness testing in Canada?

Air tightness testing in Canada is required by some provincial energy codes and certification programs rather than by the National Building Code itself, with target air-change rates and test standards (CGSB 149.10 or ASTM E779) varying by province and building type.

Air tightness testing has moved from voluntary best practice to a mandatory part of permit closeout in some Canadian jurisdictions. Whether and how it applies depends mostly on the provincial energy code path the project is following, not the base building code.

What to check first

  • Determine whether the project follows a prescriptive, performance, or certification energy compliance path.
  • Confirm the air tightness target value and test standard mandated by the applicable provincial energy code.
  • Plan the test location and timing in the construction sequence to allow remediation if needed.

Jurisdiction notes

NBC baseline

The base NBC does not mandate blower-door testing for general residential construction; it focuses on assembly-level continuity.

Provincial energy codes diverge

British Columbia's Energy Step Code, Quebec's energy regulations, and some Ontario tiers require quantitative air tightness testing for compliance.

Certification programs add criteria

Net Zero, Passive House, and ENERGY STAR programs add their own air tightness targets independent of the building code.

Work through it in this order

  1. Identify the controlling energy compliance path and any certification programs in scope.
  2. Confirm the air tightness target and the test standard the authority will accept.
  3. Schedule the blower-door test before drywall closeout if intermediate tightness verification is required.
  4. Document the result against the target and provide remediation if a re-test is needed.
  5. Coordinate the test with envelope inspections and any third-party certification verifier.

Common questions

Does the National Building Code require a blower-door test?

Not as a general rule. Testing is usually triggered by a provincial energy code performance path or certification program.

What air tightness target applies to my project?

It depends on the energy code tier, building type, and any certification program. Many BC Step Code tiers cite 2.5 ACH50 or stricter.

What test standard is referenced?

Provincial energy codes commonly reference CGSB 149.10 in Canada or ASTM E779/E1827; the controlling document depends on jurisdiction.