(originally published in The Home Monthly, December 2012)
Imagine your future home. It has no central heating or cooling system but is incredibly comfortable, with no drafts or cold spots. In fact, the temperature rarely changes by more than a degree or two from your desired setting year round. A little wall-hung heat pump in the family room extracts enough heat from the outside air on the coldest days of the year to heat the whole house. The ventilation system circulates the heat to the rest of the house and filters all of the incoming fresh air so that you are symptom-free of your allergies when you’re home. You pay less to heat and cool the house than you pay for your morning coffee in a year. If you installed a small solar system, you would easily achieve net zero.
Does this sound ridiculous? Well, it’s not. Thousands of homes like this are springing up all over Europe right now, and hundreds more have been completed or are underway here in the US. Some of them are even targeted for affordable housing. The bottom line is that the cost to build such a home isn’t that much more than the cost to build a home using conventional construction strategies.
This is the first in a series of regular columns to explore the topic of so-called “green” building. It’s hard to find an article on homes these days that does not at least touch upon the subject. But you would not be alone if you asked, What makes a home green, and is it worth the extra cost? Well, those are exactly the questions I’d like to explore with you each month.
Before I dive in, I’d like to introduce myself. I’m Mike Trolle, a thirty-year Ridgefield resident and a principal at BPC Green Builders, a Wilton-based construction management company that has focused on green building since 1999. We are approaching thirty homes now that we either built new or completely renovated, all certified as Energy Star homes by the EPA, one certified as a Health House by the American Lung Association, four certified as LEED homes by the US Green Building Council, with several of our homes having won awards for their “green-ness”.
My background includes a BA in geography, an MA in American literature, four years as a junior high teacher of English, a dozen years as a commercial real estate agent, and now going on fourteen years managing the construction and renovation of green homes. I got into this field because I’d always been interested in both home construction and protecting the environment.
In 1998, I met Bruce Coldham, an architect from Massachusetts who introduced me to the essential role of building science in creating energy efficient homes that also offered unheard of levels of performance in terms of comfort, safety, indoor air quality, and durability. I began going to the conferences of groups promoting these concepts, including the Energy and Environmental Building Association, Affordable Comfort, the Northeast Sustainable Energy Association, and I learned – boy, did I learn. To use a dated expression, “they blew my mind!” But I noticed that I was frequently the only attendee from Connecticut, which I could not believe at first, but it was true. So that set my course. I saw the opportunity and knew that this was my calling.
To begin, let’s define a green home as one that is energy efficient, water efficient, and resource efficient. Of the three, I think that energy efficiency is by far the most important. You make a home energy efficient by controlling the flows of air, heat, and moisture in and out of the home. You accomplish that by strictly defining the thermal boundaries of your home, and then creating wall and roof assemblies that are air-tight, with high levels of insulation, and that are free of thermal bridges, which are locations where heat flows freely through materials that do not insulate well, such as concrete and wood.
How well do typical homes in Connecticut fare when evaluated from the perspective of their energy efficiency? Don’t ask unless you’re ready for bad news. The answer is that our homes, both new and old for the most part, don’t have enough insulation, are not even close to air-tight, and have thermal bridges everywhere. In short, they’re not very good when compared to the performance they could offer if we took advantage of the existing science and technology.
Having read this far, I hope you’re ready to learn a little about the how and why of high performance green homes in the months to come. I invite you to send me questions, which I’ll try to answer along the way.