The Alfreds' net-zero residence, in Cumberland, Maine, is a modular design by BrightBuilt Home.
James R. Salomon The Alfreds' net-zero residence, in Cumberland, Maine, is a modular design by BrightBuilt Home.

When Shaun Alfreds and his wife decided to build a house for their family of five in Cumberland, Maine, they didn’t know if a high-performance project would be within their budget. “We aren’t wealthy by any stretch of the imagination, but we wanted an energy-efficient home,” says Alfreds, a chief operating officer at HealthInfoNet, a local health information technology company.

After some research, however, the couple realized that they achieve their dream for a nominal additional investment over the cost of a conventional house if they opted for a modular high-performance house. They chose a two-story, Cape Cod–style design from Portland, Maine–based BrightBuilt Home, and moved in last December.

At more than 3,000 square feet, the house is spacious, but its full sun exposure and a 10-kilowatt solar array of 39 photovoltaic (PV) panels should cover its energy consumption year-round. Alfreds says the house cost “almost exactly what other [builders] were bidding” for a standard, code-compliant project that was custom designed. And their small additional investment goes to building equity in the house, rather than to paying utilities.

BrightBuilt, a sister company of local firm Kaplan Thomson Architects (KTA), joins an increasing number of design companies that are expanding the market for high-performance residential projects. While KTA has custom-designed many energy-efficient houses, principal Phil Kaplan, AIA, says the firm also wanted to offer an off-the-shelf product. In 2015, it launched BrightBuilt with nine design templates. Starting at $175 to $180 per square foot, the houses bring net-zero energy to a price more people can afford. “We’re definitely seeing a lot of demand,” Kaplan says.

But some architects and builders have found ways to lower the price of net-zero housing even more.

De Verneil residence, by Deltec Homes (Ridgeline model)
Marie de Verneil De Verneil residence, by Deltec Homes (Ridgeline model)

Marie de Verneil dreamed of building a retirement home on land she owned in central Virginia. “To me, green was very important,” she says. However, her savings from teaching French and international relations at the University of Maryland, Baltimore County, didn’t seem like enough. “It’s kind of discouraging for someone like me,” she says.

Kitchen, de Verneil residence
Marie de Verneil Kitchen, de Verneil residence

Then de Verneil heard about Deltec Homes, in Asheville, N.C. The company—known for its distinctly round, prefabricated, and hurricane-resistant houses—recently launched Renew, a collection of models that use about two-thirds the energy of a conventional house and can include a PV array. De Verneil estimates she spent $250,000 on her 1,600-square-foot house (less than $160 per square foot), which includes a roof-mounted solar array. Her monthly electric bill is $30, the base fee for taxes and distribution. And when she is retired and living on a fixed income, she knows she’ll never have to say, “I can’t put the heat on.”

For those wanting to build a passive or net-zero energy house, right-sizing expectations is a crucial step to meeting one’s budget. And, as Deltec president Steve Linton adds, every project—modular or not—must be tailored to the particular site and climate. The company’s design team also conducts an energy model to evaluate site variables, solar energy capacity, building-shell size, features, and cost trade-offs.

Much of the market for high-performance housing is around single-family units in the suburbs, but the past few years have seen an uptick for multifamily dwellings and affordable housing projects in cities, including Washington, D.C., New York, and Philadelphia.

For low- and middle-income residents, in particular, an energy-efficient house can provide substantial benefits, says Orlando Velez, director of Housing Programs and Community at Habitat for Humanity of Washington, D.C. The organization recently built six passive townhouses last year in the district’s Ivy City neighborhood, which has a lot of air pollution. By creating a tight building envelope and filtering outside air, “you’re improving the air quality significantly,” Velez says. “It’s a healthier living environment.”

With savings from the lower utility bills, he says, residents may be able to spend more within the community. The organization plans to study those benefits over time to know whether energy efficiency is the best investment for its limited funds.

Ridgeline model in Deltec Homes' Renew Collection courtesy Deltec Homes Ridgeline model in Deltec Homes' Renew Collection
Interior rendering, Ridgeline model
Courtesy Deltec Homes Interior rendering, Ridgeline model

Living in a high-performance house can take some adjustment. Residents are often unfamiliar with high-tech HVAC equipment, such as energy recovery ventilators and solar water heaters. A tight building envelope also means that the size of the HVAC system can be decreased (fresh air supply is increased for indoor air quality purposes). The word that many residents use is “comfort”—indoor temperatures stay remarkably consistent across different areas of a house throughout the year.

“It’s a very dry, stabilized environment that we live in, and it’s always the same,” says Jason Specht, a Roanoke, Va.–based project manager at a credit union. In 2011, Specht worked with local firm Structures Design/Build to custom design an 1,800-square-foot certified Passive House that cost $150 per square foot. Small heat loads, like a running refrigerator, will keep an empty house in the low 60s in the winter, he says, while “cooking dinner will warm up the whole first floor.” With the house’s highly insulated walls, Specht and his wife can’t even hear a guest outside their front door.

The Specht residence, in Thaxton, Va.
Adam Cohen, Structures Design/Build The Specht residence, in Thaxton, Va.
Specht residence
Adam Cohen, Structures Design/Build Specht residence
Specht residence
Adam Cohen, Structures Design/Build Specht residence

Despite the modulated interior temperature, Specht says, “you’re living in a space that feels like you’re living outside” because of the constant influx of fresh, filtered air supplied from the mechanical system’s energy recovery ventilator.

De Verneil agrees. Because of the large windows designed to capture solar and thermal radiation at her house, “I have a sense of being part of nature,” she says.

Alfreds says that his previous house used a smart thermostat to adjust the temperature throughout the day; in the new one, “it’s actually more efficient to leave the thermostat [untouched],” he says. Achieving net-zero energy also takes diligence and effort. Alfreds fastidiously tracks the family’s energy use on a spreadsheet. “Over time, we’ll actually be more efficient once we’re aware of how we’re using the energy,” he says.

And that’s one of the challenges for designers and builders. Ultimately, the success of a high-performance house depends on its occupants. Kaplan says that education is part of the process. “There’s no such thing as a net-zero home—just net-zero people,” he says. “You have to actively be part of striving for that goal.”