Home Envelope

The outer walls, ceilings, windows, doors, and floors of a house each represent a potential site for heat and air transfer. Properly sealing and insulating a home is a cost-effective way to save up to 20% on annual heating and cooling costs. Educated homeowners or knowledgeable contractors can add insulation, seal leaks, and replace windows in a step-by-step retrofit.

Insulation reduces heat loss in cold months and heat gain in warmer months, protects the home against air leaks, and controls moisture. Despite these essential functions, only 20% of homes built before 1980 are well insulated. Adding insulation to the attic, walls, and floors of your home is extremely effective in reducing energy bills.

Windows, skylights and doors are essential for ventilation, daylighting and aesthetics. Together, they can comprise 10-20% of your home’s lost heat and air, but replacing these products is often expensive. Some upgrades, such as replacing single-pane windows with new, double-pane windows, can greatly reduce energy loss and provide long-term cost benefits. High-quality storm windows offer a low cost alternative that can reduce heat and air loss by 25-50%. Likewise, replacing or sealing and weatherizing around doors can provide significant benefits.

Sealing a home involves caulking, sealing and weather-stripping all ducts, seams, cracks, and openings to the outside. In contrast to insulation, which targets the walls and sides of the home, sealing examines the tightness of air ducts, window and door moldings, outlets and lighting, and other somewhat minute yet impactful areas of the home. Like insulating, sealing may be performed in steps and is a high return, low cost solution to reducing energy bills.