Living lightly in a net-zero home

A net-zero house on Lake Sunapee offers great views, comfortable surroundings and no bills for heat or electricity.

The family enjoys the central area of the home, which combines a library, living room, kitchen and dining area.

Most of the homeowner’s professional life had been spent promoting clean energy and progressive environmental policies, but he had never had the opportunity to live in a cutting-edge, energy-saving house. Several years ago, when he and his wife—who live in a two-hundred-year-old-house in  Concord, Massachusetts—began seriously considering retirement, their thoughts turned toward creating a vacation home based on the latest energy-saving technology. 

That home, finished about two years ago, produces as much or more electricity as it uses in a twelve-month period. This is the definition of a “net zero” building. The four-thousand-square-foot, Shingle-style house on Lake Sunapee derives its energy from a bank of thirty-nine solar panels on the south-facing roof. During the long, hot days of summer, the panels collect more energy than the homeowners use. Throughout the short, dark days of winter, they collect less electricity than is consumed. The energy that was “banked” in spring, summer and fall with the local electric company can then be used in winter. Over the period of a year, the usage evens out, so there haven’t been any electric bills to date—except $13 a month to rent the meter. Nor are there heating bills, as the house’s air-source heat pump runs on electricity.

Impressive as these results are, energy efficiency was not the couple’s only goal for this second home. They also wanted a house with plenty of views to take advantage of the lakeside location. The couple sought an open environment that would reflect the way they live—a space that was relaxing rather than fussy, and that provided lots of locations for reading. They and their two children, ages twenty-three and twenty-one, are avid readers. “We also wanted a good kitchen where people could gather and talk while we cooked,” says the wife.

The end result is a gracious, comfortable lake house with brown shingles and green trim, and an open-concept library/living room/kitchen/dining area that looks onto the water. There are at least eight places where someone can sit and read.

Walking into the house, many first-time visitors remark that they would never guess it is a net-zero house, says the homeowner. A noticeable difference for the family, however, is that the New Hampshire home is actually cozier in winter than their older (and draftier) house one hundred miles to the south.

An all-new view

Since 2002, the family has had a vacation property on Lake Sunapee, and in 2009, they found a new site, where a farmhouse sat looking onto the lake. According to local history, this house had originally been a barn on an adjacent property and had been moved to its current location many years earlier. A lawn, trees and overgrowth stretched from the house down to the lake’s edge and a boathouse. It was a nice property, according to the homeowner, but the house’s design didn’t take advantage of the lake location. When the front door opened, you saw a wall; the kitchen had only one small window.

The homeowner had a colleague who had recently had a net-zero home designed in Newton, Massachusetts, so he contacted the same architectural firm, Maclay Architects in Waitsfield, Vermont. The firm and its principal, Bill Maclay, are known for designing ecologically sustainable buildings and communities. Maclay developed a plan that called for a new house on the original foundation, and recommended solar panels and an air-source heat pump for electricity, heating and cooling.

Of first consideration was the position of the house relative to the lake and the sun. “The house is oriented to the lake, as it should be,” says Chris Cook, the project manager from Maclay Architects, “but faces west over Lake Sunapee instead of [the more desirable] south. West-facing is tough in terms of overheating in the summer.”

A long, covered porch wraps the west side of the main floor, creating outdoor living space and providing shade for the indoor living space. The home’s solar array is located on the roof on the south side of the house, where the panels can only be seen by someone standing in the neighbor’s driveway.

The back porch is an ideal spot for watching the sun set over the lake.

Challenging, Maclay says, were the usual setback issues involved with lakefront property—the house could not expand toward the lake. The final design retained the same basic footprint of the original house, with two exceptions. The front (facing away from the lake) was pushed out between eighteen and twenty-four inches to accommodate the new, larger staircase (the old one was small and narrow, and wouldn’t have met code if rebuilt today). The back porch was also expanded from six to eight feet to create a more livable space where the family enjoys the sunsets during the warmer months.

Site unseen

To determine the exterior look of the home, the couple perused magazines and hit the water for research. From a boat on the lake, the homeowners took pictures and made notes of the lakeshore houses they liked. The couple used these to provide direction to the architect as to what they were looking for—something more in keeping with the lake house vernacular than the pre-existing farmhouse. 

It was also important that the house blend in with its surroundings, that it didn’t “jump out” at people viewing it from or across the lake. “Anytime you have a great view, you have the opportunity to destroy someone else’s view,” the homeowner says. Ultimately, the house is barely visible from the lake due to the way the building nestles into its surroundings, its brown and green colors, and the surrounding foliage. “Until you’re about two hundred yards away, you won’t see the house unless you know it’s there,” the homeowner says.

Construction, cooling, heating

The homeowners enlisted builder Nick Estes of Estes & Gallup in Lyme and began working with him even before demolition started. This was on the advice of Maclay, who told the couple that—especially in the case of a net-zero house—it’s important for everyone involved in the project to understand the goals and be invested in them moving forward. It’s also helpful from a financial standpoint, Estes notes. “We were able to do a lot of the preconstruction cost tracking and estimates this way,” he says.

“It was very much a collaborative process,” says the homeowner. And it was an efficient one: demolition of the old farmhouse started the week after Labor Day in 2013, and the family moved into the new house shortly before July 4, 2014.

Early planning is important because a net-zero house is much more than solar panels; it’s really a system that requires numerous elements to function properly, and many of these must be incorporated from the beginning. First and foremost is a tight building envelope. In this house, the walls are heavily insulated to R-40 and the ceilings to R-60. A continuous air barrier on the outside of the sheathing prevents warm air from escaping in winter. The windows are Marvin Clad, triple-glazed and R-5.

The homeowners love cooking in their new kitchen, which is ideal for entertaining. The kitchen bar and the sideboard that divides the living area from the dining area were made by Steven Hayden of Steven Hayden Arts and Dave Little of Winnipesauke Forge, both of Meredith.

A net-zero house also needs to be properly ventilated. Indoor air can become polluted in super-insulated houses from daily activities such as cooking and breathing. So the house incorporates an HRV, or heat recovery ventilation system, which exchanges fresh outside air with stale inside air when doors and windows are shut. The system preheats the air
coming in so cold air isn’t constantly entering the house.

The heat pump that delivers hot air in winter can also provide cool air in summer, but that hasn’t been necessary so far. Lake breezes, ceiling fans and open windows keep the house comfortable. An extremely helpful feature is a bank of three windows at the top of the staircase landing. They face away from the lake and are so high you can’t really look out of them. Maclay recommended them because, when open, they draw warm air from the lower floor of the house, creating a chimney effect. The windows are opened and closed by remote control.

Should power fail, a backup generator kicks in to keep necessary appliances (such as the refrigerator, air pump and fan) running. Another handy and energy-saving device is a remotely operated thermostat. That way, when the family is headed to New Hampshire for the weekend, they can turn up the heat before they get there.

A bank of windows above the stair landing (partially visible at upper right) is strategically placed to provide air flow.

Comfortable interiors

The redesigned house takes advantage of its location. “With the original house, there wasn’t a whole lot of experience of being on the lake,” Cook says. “It’s a very different house now.” On the main floor, there is a combined space with a library, living room, kitchen and dining area, all with views of the lake. The kitchen is separated from the dining area by an island with stools, so guests can indeed socialize with the homeowners while they cook. The main floor also has what the homeowners call “the winter living room,” which has a direct-vent, propane-fueled fireplace that provides backup heat in the case of a power failure. Upstairs, there are three bedrooms and an office space; downstairs in the ground-level basement is a large recreation room with a pool table, utility room, multi-purpose room, workshop and exercise room.

In terms of furnishings, the couple found that most of the furniture from their former lake house fit right into the new one. Materials are net-zero suitable—carpets and paints are low-VOC-emitting and virtually all light fixtures use LEDs. The style is comfortable and casual, with exterior views and natural wood providing the strongest statements. The floors are made of reclaimed Southern pine, from Longleaf Lumber in Cambridge, Massachusetts. There are also a bench, a mantelpiece and two tables made from one giant slab of waste redwood obtained from a fallen tree outside San Francisco, California. The homeowners did order a few new pieces: the kitchen bar and stools, a sideboard that divides the living area from the dining area, and a bed are all made by craftsmen Steven Hayden of Steven Hayden Arts and Dave Little of Winnipesauke Forge, both of Meredith. These pieces combine satiny-smooth cherry with organically shaped ironwork, creating a kind of rustic-meets-art-nouveau look that works very well in the setting.

In the kitchen, the induction stove that was necessary because the house is so airtight was initially a compromise. The homeowners are serious cooks who would have preferred a gas stove. “I expected to tolerate it,” the husband says. But it turns out that he and his wife love the stove’s performance—one of the pleasant surprises involved in building a net-zero home.

Landscaping transitions

When the homeowners bought the property, unmaintained hemlocks and creeping juniper dominated the landscape and the view. Greg Grigsby of Pellettieri Associates in Warner widened the vista by gently clearing areas in back of the house (facing the lake), carefully pruning vegetation and editing the palette of miscellaneous flora. He added weathered boulders, native rock steps and footpaths to the lake and boathouse.

For the riparian buffer between the house and the lake, Grigsby used native plantings requiring little maintenance. “I always tell clients that mulch equals maintenance,” he says. “If you have exposed mulch, you’re constantly weeding or maintaining the mulch.” Plantings include a variety of shrubs, dwarf hemlocks, pines, spruce, Spiraea latifolia and native blueberry bushes. Nearer the house, there are hydrangeas and climbing roses, the latter added by the wife. Strategically located plantings near the house camouflage the compressors for the air-source heat pump. The landscaping helps the transition from the rectilinear house, to the more organically shaped terrace, to the riparian buffer, and ultimately to the lake.

A “regular” house

The house on Lake Sunapee has so far fulfilled its occupants’ goals of net-zero operation. “It’s a great house, built on time and in budget,” the homeowner says.

“It fits really well in that space,” says Estes, who adds that although he has worked on other net-zero houses, this one was special in terms of tightness of the building and quality of the trim. “It was a unique and interesting process,” he says.

The homeowner says there are several common responses when people first see the house. Visitors say, with surprise, “This looks like a regular house.” Another frequent comment is, “You can do a net-zero house in New Hampshire?” (The homeowner responds: “Hire the right architect, and pay attention to what they have to say. That’s the key.”) And last, the nicest compliment of all is: “This is a lovely home. It looks like it’s always been here.” 

The homeowners (left) share a toast with project manager Chris Cook of Maclay Architects in Waitsfield, Vermont; builder Nick Estes of Estes & Gallup in Lyme; and landscape architect Greg Grigsby of Pellettieri Associates in Warner.

Categories: Going Green, Green Design & Living