Building smart

By STEPHEN STUART

I had the good fortune to attend the Northeast Sustainable Energy Association’s Building Energy ’08 symposium, an annual conference dedicated to promoting energy conservation and sustainability. As a builder of EnergyStar homes, I am more convinced now than ever before that we consistently ask the wrong questions relative to energy conservation. Since we are asking the wrong questions, we are getting the wrong answers.

“How much will it cost?” needs to be replaced with “How much will this save me?” This question needs to be asked across the board when we consider building new homes, renovating our existing housing stock or replacing our aging and failing heating systems. We are stuck on “first cost,” and need to move beyond that limited perspective.

Likewise, we need to move from a “code compliant” frame of mind to “beyond code.” Building codes provide the minimum level of safety and performance that a building can be constructed to. We need to do this smartly. We need to know that our buildings are systems, and we need to understand the synergy that is created in wise building planning.

The study path in which I participated at the conference focused on low-energy homes, specifically super insulated homes, using technologies that can be applied either to new structures or retrofitted to old ones. The house that was modeled was a 1,792 square foot, two-story cape with an addition, built in the Boston heating climate (40 degrees average winter temperature). Built to code standards, this home would require 48 million Btu’s of energy to heat it. That is about 450 gallons of oil. By super insulating (beyond code) this same home, the annual heat load is reduced to 5.2 million Btu’s, the equivalent of 49 gallons of oil.

Now this is where it gets good—really good. By reducing the heating load to that level, you can say goodbye to the conventional oil or gas heating system—you don’t need it. How much did that cost? No: how much did you save at first cost by not having to spend $20,000 to $30,000 on a heating system? How much will you save every year by not having to buy fuel oil? A home with this level of heating efficiency could be heated with a single source heater (small wood stove) or with a small amount of electric resistance heat ( about 1,527 Kwh/year). A two-kilowatt photovoltaic system can generate the electricity, saving even more money.

By tightening the shell of our homes, we reduce the air leakage that robs us of the heat that costs us so dearly. We add a heat recovery ventilator to exchange the air at a prescribed rate, thereby keeping the indoor air quality at maximum clean, fresh levels. We have now bought ourselves a healthier home.

With proper building planning, the synergy of how systems work together provides pathways to move first-cost dollars into strategies that continue to provide a healthy return for the life of the building. We need to plan and build our buildings smarter. The “old ways“ of construction and insulation just do not work well in today‘s high priced and dwindling supply fuel economy. There are better ways to build our homes so that they are robust energy conservers, keep us healthy and conserve our resources.