When you think of an ultra-energy-efficient home, what do you picture? A sterile, modern box? A peek inside the Janssen family’s modern-farmhouse style home, where we photographed our Fall 2019 catalog, will quickly change your mind. Built using “passive house construction”—where energy use and costs are 80% less(!) than a conventionally built home—this New Jersey house was designed to beautifully blend in with its more traditional neighbors, but inside you’ll find 10-foot-high, light-filled spaces maximized for energy efficiency.
Bert Janssen and Greet Verjans, who are Belgian, moved to the U.S. eleven years ago with their sons, Karel and Toon. After six years, they decided to stop renting and put down roots. They had grown to love Madison, New Jersey, and wanted to stay there, but had trouble finding a home they loved. Finally their realtor suggested tearing down a dark, moldy 1960s ranch house that was for sale on their street and building exactly what they had in mind.
The Janssens knew they wanted high ceilings, large windows to connect with the outdoors and bring in lots of natural light—and the energy efficiency they were accustomed to in Europe. After looking online, they found Mowery Marsh Architects, whose work aligned closely with their own aesthetic. Jennifer Mowery Marsh and Brian Marsh introduced the Janssens to the concept of passive construction, which they had used in their own townhouse and several other projects.
“The overriding concept of passive construction is creating an extremely well-sealed and insulated house,” explains Jen Marsh. “Most houses are very ‘leaky’—warm air escapes around the windows and doors, and even around the wood studs or steel beams, which can conduct cold when they extend uninterrupted from inside to outside.” By packing four to five times more insulation into the house (using dense packed cellulose rather than spray foam), creating a continuous barrier to prevent leaks, and using triple-glazed, airtight windows, the house acts like a thermos, keeping the heat (or air conditioning) in.
The other key ingredient is ventilation. An energy recovery ventilator (ERV), or what the architects call a “magic box,” constantly brings in fresh air and—here’s the magic part—also captures and transfers the heat from the outgoing air, so all that energy and warmth is not lost. “Just as important as the energy savings is the very clean air quality and consistent, even temperature of a passive house,” says Jen. “Especially for people with allergies or asthma, the air quality makes a huge difference—no soot or pollution are coming in, and every room is a comfortable temperature.”
“Passive construction is a little more expensive, but it almost becomes a wash by the end of construction,” says Brian. “The European windows we use are the same price as high-end American windows, the mechanical systems needed are smaller so they cost less, and energy bills are so much lower, the savings really adds up over time. You can reduce your heating and cooling needs by as much as 90%.”
When it came to the look of the house and the interiors, Greet says, “We wanted a lot of light, and high ceilings and large windows to get a feeling of openness and connection to the outdoors, but we also still wanted some separation between rooms.” You can see the kitchen from the living room, but thanks to the L-shaped design, it’s not all in the same space.
“It’s not that large of a house but it feels very open and airy,” she says. “Our living room is our family room. If the kids get too crazy, we send them to the basement.”
The kitchen was also really important to them. “My husband loves to cook and we spend a lot of time there,” says Greet. “We were interested in natural materials; we love a Scandinavian look. We wanted it to feel modern but warm. It’s a nice combination of wood, white and softer colors.”
From the architects’ perspective, the biggest design challenge was the floor-to-ceiling windows. “They’re great in winter for passive solar heat gain, but you want to shield them from too much heat in summer,” says Brian. They added a trellis over the living room windows to help shade them, and planted birch trees along the back terrace to provide shady, dappled light in summer.
“In the master bedroom, we see the tops of the trees through the tall windows and it feels like we’re in our own little getaway in the middle of the woods, not the suburbs,” Greet says. “This house is like a wonderful, relaxing oasis.”