This section of the building envelope chapter addresses the requirements for the building shell, excluding fenestration. Components of the building shell include walls, floors, and roofs and/or ceilings. Fenestration, and windows and doors are addressed in Section 3.5 Fenestration.
Joints and Other Openings
Air leakage through joints, penetrations, cracks, holes and openings around windows, doors, walls, roofs and floors can result in higher energy use for home heating and cooling than necessary. The following openings in the building envelope shall be caulked, gasketed, weatherstripped or otherwise sealed:
A. Exterior joints around window and door frames, including doors between the house and garage, between interior HVAC closets and conditioned space, between attic access and conditioned space, between wall sole plates and the floor, exterior panels and all siding materials;
B. Openings for plumbing, electricity, and gas lines in exterior walls, ceilings and floors;
C. Openings in the attic floor (such as where ceiling panels meet interior and exterior walls and masonry fireplaces);
D. Openings around exhaust ducts such as those for clothes dryers;
E. Weatherstripping is required for all field-fabricated operable windows and doors (other windows and doors must meet infiltration requirements and be laboratory tested). This includes doors between the garage and the house, between interior HVAC closets and conditioned space, and between the attic access and conditioned space (§110.6(b); and
F. All other such openings in the building envelope.
Alternative techniques may be used to meet the mandatory caulking and sealing requirements for exterior walls. These include, but are not limited to:
1. Stucco
2. Caulking and taping all joints between wall components (e.g., between slats in wood slat walls
3. Building wraps
4. Rigid wall insulation installed continuously on the exterior of the building
