EEA Undersecretary for Energy, Executive Office of Energy and Environmental Affairs
My family has had a small cabin in New Hampshire for about ten years. We set our propane heater at a very low level in the winter when we’re not there to make sure our pipes don’t freeze — and turn it off entirely in the summer — and we heat primarily with wood when we are there, so it’s fairly energy-efficient. However, with an expanding family, we have seriously outgrown the cabin.
To make a very long story (perhaps to be pursued in additional blog entries) short, we decided to build a new house, but only after deciding to make it as energy-efficient as we possibly could. Our aspirational goal is the Passive House standard, which is becoming the norm for new buildings in some parts of Austria and Germany, and achieves reduction in heating-related energy of about 90 percent.
The house, which is under construction, will be super-insulated — to a degree very unusual in this country. From outside to inside, there are four inches of styrofoam, two inches of sprayed polyisocyanurate, and then six inches of blown in cellulose. This gives the walls an insulation value of R60. The house is essentially framed twice — a house within a house — to allow for the blown-in cellulose insulation. The windows are triple pane, with inert gas between the panes. We were unable to find American-made windows that met our specs, and ultimately ended up with windows from Ontario, Canada.
While these measures are somewhat expensive, the costs are at least partially offset by eliminating entirely the need for a furnace (and this is in central New Hampshire). We anticipate using only a very small wood or wood pellet stove, a back-up propane heater (which we hope we will not need to use at all) to prevent a freeze-up, and minimal electric heat in the bedrooms when they’re occupied.
Despite all this, the house does not quite achieve Passive House standards, for a few reasons. First, we bought the property largely because of the view, which is to the north and east. With Passive House construction, houses are oriented towards the south, with very few windows facing north. Passive Houses also tend to be small, but the reason for our house is to accommodate a crowd.
At this point, it is very much a work in progress — more reports as we move forward…