Best Bang for the Buck

For the last five years I have been focusing primarily on making homes in the Monadnock region more energy efficient. I have conducted numerous energy audits and have completed a few dozen major energy retro-fits. This means remodeling for maximum energy efficiency based on a prioritized list of improvements called out by the audit. I feel that I have a pretty good handle on what is worth pursuing and what is a waste of time and resources. Of our utility bills, the heating bill, by and large, takes the largest chunk of the pie.

Most New England homes consume ridiculous amounts of precious fossil fuels for home heating. Why? Because our homes are not air sealed and insulated well enough.Some of us may pride ourselves on being independent by having a few cords of backup firewood, but that stance doesn’t address the heating load of the building.

Think of it this way: thin walls with air leaks need a large furnace or heating source. Thick walls with few air leaks mean a very small furnace or heating source. This is compounded by the “stack effect.” The heated air that escapes through the roof in the winter is replaced by mostly cold air that enters at the basement and lower levels of the home. In essence, it’s a thermal chimney that creates a rising air current. The wall and window areas in between are more in the neutral zone.

Address the stack effect and stop the dynamic air currents that rob your home ofheat. The most dramatic improvements occur when cellars are air sealed and insulated and attics are air sealed and insulated. Closed cell spray foam insulation works well in cellars and crawl spaces. For attics and roof systems, blown in cellulose insulation coupled with varying amounts of spray foam for air sealing works exceptionally well.

Say you were able to invest $15,000 of your hard earned cash into energy improvements. You conduct an energy audit and create a prioritized list of energy improvements. Most often, the roof, attic, crawl space and cellar is where the majority of the attention would probably go. Payback can be an immediate increase in comfort especially in our historic homes.

Dollar payback depends on the occupants but less than 7 years is possible. Put $15,000 into new windows and the payback could go from 18 years to 100 years or more! You may have lower maintenance and prettier windows, but the overall energy savings just cannot compete with improvements made in cellars and roof systems if the audit pushes the project to those directions.

Of course, we don’t all have $15,000 to put into making our homes warm. Weather stripping doors and windows and doing some air sealing with interior caulking are certainly more affordable and can be fairly effective with a limited budget. Storm windows still have a place in retro-fitting historic homes.

So what’s the best bang for the buck: An energy audit with air sealing and insulation of cellars, crawl spaces and roof systems. The audit will show you where other improvements such as ventilation, lighting and heating system upgrades come into play. Then you can add those slick looking solar photovoltaic panels to your roof, now that your home is not built like a barn.

Doug Walker, of Walker Building & Design, is an accredited Building Performance Institute energy auditor, a builder/remodeler involved in energy efficient construction for over 30 years and a director of the Monadnock Sustainability Network, whose mission is to promote credible, sustainable/ “green” practices in the region.