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CHECKLIST · PART 3 BUILDINGS
Large building airtightness test: the checklist from design to test day
Most failed or delayed tests come from preparation, not the envelope. Use this checklist from the construction documents stage to test day.
AT A GLANCE
- Standard: ASTM E3158-18, read with the City of Toronto testing protocol for Toronto Green Standard projects
- Toronto Tier 2 target: 2.0 L/s per m² of enclosure area at 75 Pa or less
- Enbridge incentive: test before the envelope is fully constructed
1. At design and construction documents (50 to 75%)
- Appoint a qualified third-party testing agency and sign the contract (Toronto asks for it at this stage)
- Mark the intended air barrier line on the drawings, through every wall, roof and below-grade transition
- Define the test boundary: which volumes are inside, and which (parkades, vented attics, shafts) are outside
- Submit the test plan: fan calculations, fan locations and power sources, the procedure and the people involved
- Decide whole-building or guarded testing; for towers, plan the sampled floors (podium, base and top of tower, unique floors, two floors per ten)
- For the Enbridge incentive, contact Enbridge Gas before the project starts
2. Before the test is booked
- All air barrier materials, assemblies and systems in the test boundary installed, including HVAC (heating, ventilation and air conditioning) equipment, ducts and fittings
- Windows, exterior doors and roof openings installed and closable
- Agree in writing who seals HVAC penetrations, intake and exhaust openings, overhead doors and dock levellers
- Plan a mid-construction test or leak walk if possible, while the air barrier is still exposed and cheap to fix
3. On test day
- Power available at each fan location
- Someone who can put HVAC and combustion equipment into test mode, and restore it after
- Access to every space inside the boundary, including suites, service rooms and the roof
- Safe access to HVAC equipment, doors, penetrations and dampers
- Interior doors open (or as the plan specifies), trades off site or keeping exterior doors closed
- Weather check: high wind can make the test unreliable, so keep a backup date
4. After the test
- Report results normalized to the enclosure area, all six sides, above and below grade
- For guarded tests, report each test separately; each must meet the target
- Send the final report to the City and the third-party Tier 2 verifier
- If the target is missed, the report includes practical steps to find and seal the main leaks, then retest
- For the Enbridge incentive, submit the final testing report to claim it
Budgeting? See what large building testing costs, or talk to us about your project.
Sources: City of Toronto: Whole Building Air Leakage Testing Protocol (revised November 2022) · Toronto Green Standard v4 · Enbridge Gas: Commercial Airtightness Testing Program.
Quick answers
When should the airtightness test plan be submitted in Toronto?
Under the City of Toronto protocol, the testing agency submits a plan at the 50 to 75% construction documents stage, with fan calculations, fan locations and power, the procedure and the people involved.
When does the test happen?
Once all air barrier materials, assemblies and systems inside the test boundary are installed, including HVAC equipment, ducts and fittings. For the Enbridge incentive, testing must happen before the envelope is fully constructed.
What is the Toronto target?
Toronto Green Standard Tier 2 targets 2.0 L/s per square metre of enclosure area at 75 Pa or less.