Why Air Sealing Matters for Massachusetts New Construction
Air sealing is the single most important step in achieving Massachusetts Stretch Energy Code compliance. The blower door test requirement of 3.0 ACH50 cannot be met without systematic air sealing — and failing the blower door test means no certificate of occupancy.
Massachusetts Air Sealing Requirements
The Massachusetts Stretch Energy Code requires new residential construction to achieve 3.0 ACH50 or better on a blower door test. This is significantly more stringent than the standard code requirement of 5.0 ACH50.
Where to Air Seal in New Construction
The most important air sealing locations in Massachusetts new construction are: band joists and rim joists at the foundation, all penetrations through the building envelope (pipes, wires, ducts), attic hatch, top plates where walls meet ceilings, recessed light fixtures in insulated ceilings, and window and door rough openings.
Best Materials for Air Sealing
- Two-part spray foam for larger gaps and penetrations
- Caulk for small gaps around windows, doors, and pipes
- Rigid foam board with canned foam for large openings
- Weatherstripping for attic hatches and mechanical room doors
- Airtight electrical boxes on exterior walls
Pre-Drywall Air Sealing Inspection
The best time to identify and fix air leaks is before drywall is installed. We offer pre-drywall diagnostic blower door tests that identify problem areas while they are still accessible and easy to fix — avoiding costly retesting after drywall is in.
Schedule Air Sealing Guidance
Home Energy Efficiency Consultants provides blower door testing, diagnostic services, and air sealing guidance across Massachusetts. Our owner has 25+ years of construction experience and knows exactly what to look for. Call (617) 501-6788 for a free quote.
