What maximum air leakage rate is allowed for the air barrier system?
Under NECB 2025 the air barrier system must not exceed a normalized air leakage rate of 1.50 L/(s·m²) at 75 Pa.
Conditions and exceptions
- Measured across the whole air barrier system, not a single assembly.
- The 75 Pa reference pressure is part of the requirement — a rate quoted at another pressure is not comparable.
- Testing and verification requirements accompany the limit.
Where this comes from
National Energy Code of Canada for Buildings — NECB 2025
This page states the requirement and points you to the publisher. It does not reproduce the code text — read the provision itself at the official source below.
Read the official text at NRC — Codes Canada publications →Verify this against the code edition actually adopted where you are building. Provinces, territories, and municipalities amend on their own schedules, and where the governing document and this page disagree, the governing document controls. This is not legal, engineering, or permitting advice. Last reviewed 2026-08-12.
Ask your own code question
Canadian Codes answers questions like this one from national, provincial, territorial, and municipal sources, and cites the document, section, and page so you can check it yourself.
Try it free →Related questions
- How high does a guard need to be on a residential deck? Canada
- When can an exterior guard be lower than 1 070 mm? Canada
- What is the minimum ceiling height for a bedroom? Canada
- What is the minimum ceiling height in an unfinished basement? Canada
- What ceiling height is required in a secondary suite? Canada
- How wide must a hallway be inside a dwelling unit? Canada
- When do two areas count as a combination room? Canada
- At what supported joist span do the basic footing width tables stop applying? Canada
- What is the minimum clear height in a storage garage? Canada
- How often must self-contained emergency lighting be tested? Canada
- What minimum slope is required for a drainage pipe NPS 3 or smaller? Canada
- How high must a guard be on a deck in Ontario? Ontario
- What is the minimum ceiling height for a bedroom in Ontario? Ontario
- What ceiling height is required in a basement in Ontario? Ontario
- What ceiling height do I need for a basement apartment in Ontario? Ontario
- What clear height is required over stairs in an Alberta secondary suite? Alberta
- When can an exterior guard on a BC house be 900 mm high? British Columbia
- Does the Manitoba Building Code apply to a shed under 10 m²? Manitoba
- Where are carbon monoxide alarms required in Manitoba? Manitoba
- What size egress window does a Manitoba basement need? Manitoba
- What fire separation is required between an attached garage and a Manitoba dwelling? Manitoba