Building thermal envelope

The building thermal envelope shall comply with Sections R402.4.1.1. The sealing methods between dissimilar materials shall allow for differential expansion and contraction.

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 Where required by the code official, an approved third party shall inspect all components and verify compliance.

Air Leakage Testing

The building or dwelling unit shall be tested and verified as having an air leakage rate of not exceeding 5 air changes per hour in Climate Zones 1 and 2. An air change per hour is the movement of an air quantity equal to the interior home volume Testing shall be conducted with a blower door at a pressure of 0.2 inches w.g. (50 Pascals). Where required by the code official, testing shall be conducted by an approved third party. A written report of the results of the test shall be signed by the party conducting the test and provided to the code official. Testing shall be performed at any time after creation of all penetrations of the building thermal envelope.

During testing:

1. Exterior windows and doors, fireplace and stove doors shall be closed, but not sealed,beyond the intended weather stripping or other infiltration control measures;
2. Dampers including exhaust, intake, makeup air, back draft 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;
4. Exterior doors for continuous ventilation systems and heat recovery ventilators shall be closed and 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.

Fireplaces

New wood-burning fireplaces shall have tight-fitting flue dampers and outdoor combustion air.

Fenestration air leakage

Windows, skylights and sliding glass doors shall have an air infiltration rate of no more than 0.3 cfm per square foot, and swinging doors no more than 0.5 cfm per square foot when tested by an accredited, independent laboratory and listed and labeled by the manufacturer.

Exception: Site-built windows, skylights and doors.