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WA State Energy Code Update 2021 IECC

Blower Door Testing & Air Sealing

Effective July 1, 2023.

Based on the 2021 IECC. Please note that "Residential" includes One- and Two-family dwellings, Townhouses, and  R-3 buildings three stories or less, and Group R-2 buildings three stories or less with dwelling units that are accessed directly from the exterior. "Commercial" includes all buildings not covered under "Residential." 

We offer blower door tests and duct leakage tests that are both energy-saving and in compliance with Washington State’s required Air Leakage Testing (R402.4.1.2) SAME DAY TESTING CALL 425.608.9553

R402.4 Air leakage.

The thermal building envelope shall be constructed to limit air leakage following Sections R402.4.1 through R402.4.6 requirements. R402.4.1 Building thermal envelope air leakage. The building thermal envelope shall comply with Sections R402.4.1.1 through R402.4.1.3. The sealing methods between dissimilar materials shall allow for differential expansion and contraction. R402.4.1.1 Installation. The components of the building thermal envelope, as listed in Table R402.4.1.1 shall be installed following the manufacturer's instructions and the criteria listed in Table R402.4.1.1, as applicable to the construction method. Where required by the code official, an approved third party shall inspect all components and verify compliance.

R402.4.1.2 Testing. The building or dwelling unit shall be tested for air leakage. Testing shall follow RESNET/ICC 380, ASTM E779, or ASTM E1827. Test pressure and leakage rate shall comply with Section R402.1.3. A written report of the test results, including verified location and time stamp of the test date, shall be signed by the testing agency and provided to the building owner and code official. Testing shall be performed at any time after the creation of all penetrations of the building's thermal envelope. Once visual inspection has confirmed air sealing has been conducted in accordance with Table R402.4.1.1, operable windows and doors manufactured by small businesses are permitted to be sealed off at the frame prior to the test. Testing of single-family dwellings and townhouses shall be conducted in accordance with RESNET/ICC 380. Test pressure and leakage rate shall comply with Section R402.1.3.1. For Group R-2 occupancies, testing shall be conducted in accordance with ASTM E779, ASTM E1827, or ASTM E3158. Test pressure and leakage rate shall comply with Section R402.1.3.2. The individual performing the air leakage test shall be trained and certified by a certification body that is, at the time of permit application, an ISO 17024 accredited certification body including, but not limited to, the Air Barrier Association of America.

R402.4.1.3 Leakage rate.

Detached one- and two-family dwellings and multiple single-family dwellings (townhouses) shall comply with Section R402. Group R-2 multifamily buildings shall comply with Section R402. R402. Dwelling unit leakage rate. The maximum air leakage rate for any dwelling unit under any compliance path shall not exceed 4.0 air changes per hour. Testing shall be conducted with a blower door test at a test pressure of 0.2 inches w.g. (50 Pa).

Exception: Additions tested with the existing home having a combined maximum air leakage rate of 7 air changes per hour. To qualify for this exception, the date of construction of the existing dwelling must be prior to the 2009 Washington State Energy Code. R402. Group R-2 multifamily building leakage rate. For Group R-2 multifamily buildings, the maximum leakage rate for any dwelling unit shall not exceed 0.25 cfm per square foot of the dwelling unit enclosure area. Testing shall be conducted with a blower door at a test pressure of 0.2 inches w.g. (50 Pa). Doors and windows of adjacent dwelling units (including top and bottom units) shall be open to the outside during the test.

During testing:

1. Exterior windows and doors, fireplace, and stove doors shall be closed, but not sealed, beyond the intended weatherstripping or other infiltration control measures.

2. Dampers including exhaust, intake, makeup air, backdraft and flue dampers shall be closed, but not sealed beyond intended infiltration control measures.

3. Interior doors, if installed at the time of the test, shall be open, and access hatches to conditioned crawl spaces and conditioned attics shall be open.

4. Exterior or interior terminations for continuous ventilation systems and heat recovery ventilators shall be sealed. 2021 Washington State Energy Code RE-27

5. Heating and cooling systems, if installed at the time of the test, shall be turned off.

6. Supply and return registers, if installed at the time of the test, shall be fully open. Exception: Additions less than 500 square feet of conditioned floor area.

Fail a test? Seal the building tight with AeroBarrier.

AeroBarrier is an interior-applied air sealing system that seals building envelope leaks up to 1/2″. The waterborne sealant is aerosolized and injected into a pressurized home. The sealant is self-guided to the edges of visible and invisible leaks to create a seal by accumulating across the leaking surface. The sealant is applied within 60-90 minutes and dries quickly before the system cleanup is complete. This ensures construction can resume shortly after the process is complete with little to no impact on standard construction schedules. The AeroBarrier system measures envelope leakage in real-time, enabling the system to dial-in specific air leakage requirements with precision and guarantee the results.

AeroBarrier has sealed houses to as low as 0.19 ACH50. But the value is in the system’s ability to allow builders to seal a home to as tight as it is designed for. AeroBarrier can meet any IECC, Passive House, LEED, Well Standard, ENERGY STAR, or Net Zero requirement.

Need AeroSeal sealing? Contact us 425.608.9553. Watch the Video to Learn More!