In early January, Nancy Rae Mallery, the publisher of Green Energy Times spoke in a very brief interview with builder Bob Irving. The questions and answers went as follows.:
NRM: Did you know we are planning on publishing an article about the place you built in Concord that won the net-zero award? I recall your initial hopes of getting this job. All I can say is what an amazing job you did! Congratulations.
BI: You are too nice. I reached a good place where those houses aren’t amazing, they are just the same-old thing. That’s where I wanted to be.
NRM: Isn’t that exactly how it should be, with all buildings being net-zero?
BI: Exactly! That’s what I mean.
So here is the story of a house that is not amazing to Bob Irving, but it won an award because it is, well, amazing.
Carol Voloshin works for Stonyfield Organic. Dan DiPiro had also worked there for eight years starting in 2006, when the company’s roof was covered by the largest solar array in New Hampshire. The experience of working for an environmentally-friendly business, now a certified B-Corp had its effects on them.
When Carol Voloshin and Dan DiPiro wanted to build a new home, they had some rather remarkable goals in mind. Voloshin wanted to be very near water, and DiPiro wanted their home to use net-zero energy. So, they built a net-zero home on land on the Contoocook River in Concord, New Hampshire.
This was a structure that had its share of challenges. Because it was built so close to the river, actually in the flood plain, the home had to be elevated ten feet to reduce any risk of water problems. This meant that the first floor had to be specially designed to be supported by a set of trusses, and insulation under it had to be unusually thick. Bob Irving said he wanted the insulation under the floor to be in the same range as the roof, which is R-64.
The walls are also insulated with packed cellulose, to R-37. As double-stud walls, they have almost no thermal bridges. The home has triple-glazed Logic brand windows to retain heat as well as possible.
Special care was given to air-sealing, which Irving says can make the difference between an attempt at efficiency and a great house. This means that good ventilation is vital, and the house has a Broan heat recovery system. Since there is no basement, the water heater had to be on the first floor, and a Rennai Marathon heater was chosen for that role.
The heating system is more complex. A pellet stove can provide all the heat, but it may not be necessary to use it on any but the coldest nights. There is a three-head heat pump system in the house which can do heating and cooling through most of the year.
As efficient as it was, the house had not yet achieved the net-zero status DiPiro had hoped for. The Home Energy Rating System (HERS) rating was 44, which meant it was 56% more energy efficient than a standard new home.
Net-zero status came with a rooftop solar array installed by ReVision Energy, which has offices in Maine, New Hampshire, and Massachusetts. ReVision installed thirty solar panels to produce an array of 9.15 kilowatts. The energy from this array contributes about 10,000 kilowatt-hours of energy each year to cover the household energy needs. And with that, the HERS rating dropped from 44 to -3, meaning that what had been a very energy-efficient structure was now net-positive.
Voloshin and DiPiro now live in a house that creates more energy than it uses. This is not amazing. We knew it could be done. But they were the ones that did it, with some help from R.H. Irving Home Builders, ReVision Energy, and some others. What really should happen with every home actually did happen, and perhaps that is amazing.
Certainly, the people at NHSaves seem to think it’s amazing. The Voloshin-DiPiro house won third place in the NHSaves Drive to Net-Zero Competition. Our congratulations to all.
R.H. Irving Home Builders’ web site is rhirvinghomebuilders.com.
ReVision Energy’s web site is revisionenergy.com.