With all the talk about building green these days, you would think it is something new, maybe solar panels on the roof and high-tech solutions with complicated circuitry and untried ideas. The truth is, you can reduce the energy consumption of a new home or retrofit by as much as 70%, with conventional construction done right.
Think of it. If all the standard energy-saving measures like insulation and caulking were done with the same care and attention to detail as the cabinetwork and finish carpentry, the air you pay to heat would stay in the house and keep you warm, instead of finding its way outside through the walls and attic.
There is a standard of proper wall and ceiling insulation, but the truth is very few of those people whose job it is get it right. This is partly because it is one of the lowest-paid jobs in the business, and the workers are often paid by piecework. It is also because too few people–including owners, contractors, and building inspectors–insist on a good job of installation. The result is–yes the work is done cheaply and quickly. It is the building owners who pay for it over the years, in excess energy bills that need never have been so high.
The standard is known specifically as “Quality Insulation Installation,” or QII. When I asked an insulating contractor if his company provided QII, his answer was, “We train our installers well.” It was his business, and he hadn’t even heard of the standard!
Here is a part of the procedure, paraphrased from Energy Star (energystar.gov):
a. Wall stud cavities should be caulked or foamed to provide a substantially air-tight envelope to the outdoors, attic, garage and crawl space. Top and bottom plates should be continuous and have any openings sealed. Special attention should be paid to plumbing and wiring penetrations through the top plates, electrical boxes that penetrate the sheathing, and the sheathing sealed to the bottom plate.
b. Pay special attention to installation of air-tight air barriers for walls adjoining exterior walls or unconditioned spaces, including walls behind showers/tubs and behind fireplaces, insulated attic kneewalls, staircase walls, the intersection of porch roofs and exterior walls, and skylight shaft walls.
c. Fill each cavity side-to-side, top-to-bottom, and front-to-back. Batt insulation should be installed to fill the cavity and be in contact with the sheathing on the back, the studs at the sides, and the wallboard on the front – no gaps or voids.
Before you spend money on new windows, or blow-in insulation to the walls of your older home, do these two things first. Go in your crawl space and attic, and air-seal every opening you can find with spray foam insulation, and insulate the attic to R-30 or better (have an electrician take a look up there first, to be sure your any lighting or wiring is suitable for burial in insulation). You’ll be surprised and the new-found comfort. Some people will tell you doing these things is a waste of money, but the truth is they are the cheapest investment you can make, with the best results in savings and comfort.
First published in the Pacifica Tribune 3/24/10
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