Washington Administrative Code › Title 51 - Enterprise Services, Department of (Building Code Council) › Chapter 51-11R - State Building Code adoption and amendment of the 2021 edition of the International Energy Conservation Code, Residential › Section 51-11R-40240 - Section R402.4-Air leakage

Current through Register Vol. 24-14, July 15, 2024
R402.4
Air
			 leakage.
The
building thermal envelope
shall be
			 constructed to limit air leakage in accordance with the requirements of
			 Sections R402.4.1 through R402.4.4.
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 in accordance with the manufacturer's
			 instructions and the criteria listed in Table R402.4.1.1, as applicable to the
			 method of construction. 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 be conducted in accordance with 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 date of the test, shall be signed by the testing agency and
			 provided to the building owner and
code official
. Testing
			 shall be performed at any time after creation of all penetrations of the
building 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 business
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.
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, 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;
5. Heating and cooling
			 systems, if installed at the time of the test, shall be turned off;
			 and
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.
R402.4.1.3
Leakage rate.
Detached one- and two-family dwellings and multiple single-family dwellings
			 (townhouses) shall comply with Section R402.4.1.3.1. Group R-2 multifamily
			 buildings shall comply with Section R402.4.1.3.2.
R402.4.1.3.1
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.
R402.4.1.3.2
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.