You'd Never Guess This NYC Townhouse Is a Passivhaus

The thing about these renovations of New York townhouses by Baxt Ingui Architects is that they don't look like what people expect Passivhaus renovations to look like. Many people think there will be teensy windows that don't open, and instead, they are full of light, air, and openness.

Michael Ingui tells Treehugger that sometimes he doesn't even tell clients they are getting the Passivhaus EnerPHit renovation standard; they are not the type to care about the cost of heating or cooling. He does tell them the house will be incredibly quiet and comfortable thanks to the careful sealing, thick insulation, and triple-glazed windows. Clients like the fact that there is a constant supply of filtered fresh air, particularly when forest fires are affecting air quality even in New York City. And then there is a big benefit for a townhouse in the city: When you seal a party wall so tightly that the air can't get through, neither can the bugs.

The Carroll Gardens Passive Townhouse is a good example of how architects can deliver all the benefits of Passivhaus in an old New York townhouse. According to the architects:

"The house, originally built in the late 1800s, had an intact brownstone façade and wood cornice, while much of the historical interior character had been modified or damaged, including a sagging floor structure and missing architectural details. The team, including Michael Ingui and Maggie Hummel of Baxt Ingui Architects, Cramer Silkworth of Baukraft Engineering, and Max Michel of M2 Contractors, worked collaboratively to create a house that blended the historic proportions of the townhouse with a number of modern, sculptural elements."

The "electrify everything" and the heat pump crowds will like this house; it's got a heat pump water heater, clothes dryer, and HVAC. Heat pumps are easy in a Passivhaus because the loads are so small. The architects explain:

"Through Passive House detailing and insulation, the house requires almost no heat, regardless of how cold it is during the Northeast winters. We were able to eliminate the radiators and replace them with a system that uses minimal ductwork."

Notably, the house also has an induction cooktop. Some Baxt Ingui clients insist on giant commercial-style gas ranges, but Ingui tells Treehugger they are making headway convincing clients that induction ranges are fine.

The Carroll Gardens Passive House puts paid to the idea that Passivhaus designs can't have lots of natural light. I used to say "the best window isn't as good as a lousy wall" but that's no longer true when you are talking about these high-performance Passivhaus windows from Zola, which have R values of up to R-11. The result: lots of natural light.

 "Since space is so highly valued in a narrow townhouse, the team paid close attention to the floor openings that were created at the rear parlor and the stairwell in the center of the hall. It was important that these openings allow light into the middle of the home and create a continuously open and airy experience as you ascend through each floor. A mix of natural wood elements helped to create an environment that is both modern and warm."

The Carroll Gardens Passive Townhouse, and much of the work of Baxt Ingui, provide a great demonstration of why the Passivhaus approach makes so much sense in these times. While this is a 4,058-square-foot luxury renovation, the principles are universal. Instead of being net-zero, it needs almost no heating or cooling at all. It doesn't get fist pumps for heat pumps, because the heat pumps it has make a trivial contribution compared to the real work being done by the fabric of the house itself.

And don't forget the contribution of the urban form and building type; on a narrow townhouse, the biggest surfaces, the sidewalls, are shared, significantly reducing heat loss. And it's dense enough that you don't have to drive to get a quart of milk.

It's why I keep coming back to Passivhaus—because the first thing we have to do is reduce demand for energy, which makes it so much easier to get to zero carbon emissions. Everything else is just a distraction.