Nice Shades: This NYC Passivhaus Condo Has Terra-Cotta Baguettes

New York City has a new condominium on Columbus Avenue: Charlotte of the Upper West Side. It is a wonderful example of a point I often make: Passivhaus isn't just a standard of energy—it's a standard of luxury.

Passivhaus started primarily as an energy standard, but as we have also noted, the three most important things about Passivhaus are comfort, comfort, and comfort. People who can afford condos like this are not particularly worried about paying the heating bills, but they have other expectations. The developer, Roe Corporation, and the architects, BKSK, get this.

In their sustainability and wellness pitch, the two companies put their priorities in order: "Robust insulation and airtight seals minimize airleaks and drafts, keeping rooms consistently comfortable and quiet while significantly reducing energy consumption."

We have a continuing series called "nice shades," where we extoll the virtues of keeping the heat out before it gets in rather than paying to remove it after. Charlotte has some of the nicest shades we have seen yet, terra-cotta "baguette-shaped" fins made by Ceipo Ceramiche. They cut the solar gain in summer but let the sun in during winter, which is useful when running the Passivhaus numbers.

One can also cut solar gain with tinted or mirrored glass, but here they specify Guardian’s UltraClear glazing": "This museum-quality low-iron glass offers brilliant neutrality and a light transmission rate of more than 91 percent for incomparable esthetics and an incredible viewing experience."

They also have lovely sketches showing the benefits. "In winter, the low-angled sun passes between the louvers, bringing in welcome warmth and light during the colder months of the year."

The Zola wood and aluminum windows are quadruple-glazed, and the marketing materials note the benefits: silence and no drafts.

"Window panes and wood frames stay cool to the touch on very hot summer days and warm in winter. Instead of shifting seasonally between stifling heat and freezing cold, room temperatures stay consistent and comfortable. On the coldest days, you could sit right next to the window without a heater or having to wear a thick sweater."

This pays for itself; in a lot of buildings with conventional glazing, you can't even use the first couple of feet of real estate near the windows because you cook in summer and freeze in winter.

The marketing materials continue on this theme of comfort and air quality.

"This type of house provides a high level of physical and mental comfort to residents, with constant year-round temperatures and remarkably quiet living space. Drafts and hot and cold spots are eliminated as temperatures are kept consistent throughout the unit, maximizing residents’ comfort. This is achieved through extensive insulation to prevent heat loss or gain and the introduction of fresh air through specially built vents that transfer the temperature to the incoming fresh air. The constant air exchange introduces fresh air and exhausts stale air, eliminating fumes and odors."

This would be the ERV or energy recovery ventilator. Each residential unit has its own Zehnder ERV. taking air from the bathrooms and feeding it back to the living spaces after it has passed through high-efficiency MERV-13 filters and, unusually, a germicidal ultraviolet C system that eliminates viruses, bacteria, and mold.

"The UV system has been engineered into all of the fresh air, ERV, and residential HVAC units in the entire building, including all common areas, with remote sensors to detect bulb outages. UV light is applied on the supply side of the units, which dramatically reduces or eliminates biological contaminant buildup on the heat-exchange fins and ductwork. This results in even cleaner air, with high long-term operational efficiency."

It's surprising because UV-C systems are usually found where the air is recirculated, and in Passivhaus ventilation, there is no recirculation—just fresh air. But we are on Columbus Avenue in New York City and "fresh" probably has a different meaning there.

One of the toughest criteria for Passivhaus is air tightness, which is measured with a blower door. Writing in Green Building & Design, BKSK partner Todd Poisson described how hard it was to do this; there were leaks around the windows and the louvres, but also leaks in the exterior concrete masonry units, even though a liquid air barrier had been applied. "The holes were very small and difficult to locate so to keep things on schedule, the team decided to use AeroBarrier, a product that is sprayed into the air while the building is pressurized," said Poisson. "As the AeroBarrier makes contact with holes in the air barrier, the particles build up to seal off the openings." It worked.

There were also problems with the design of garbage chute hatches; they had to develop a special fully gasketed door to integrate it with the kitchen cabinetry. The elevator opens directly into the suite.

I would have thought this would cause similar problems but the architects tell Treehugger: "[We] incorporated apartment entry side 'zero clearance' pocket doors at every apartment’s elevator threshold. The doors give an extra layer of personal security as well as air/acoustic attenuation. In addition to the zero clearance pocket doors, the code required elevator shaft ventilation has a damper that communicates with the fire alarm system, opening the vent only when there is a fire event to exhaust smoke from the building. The rest of the time, the vent is sealed."

There are many other lovely technical touches, such as four layers of Quietrock drywall between bedrooms within the unit and "robust" insulation in the floors. The wood is all FSC-certified, and the interior finishes are all low-VOC (volatile organic compounds). Given the concern with healthy interiors, I was disappointed to see the units have monster Wolf 48-inch 6-burner gas ranges. To comply with the PHI standard, they have big honking 46-inch wide 900 CFM exhaust hoods that look like they are too shallow and set too far away to really capture all the fumes, but it's hard to pry high-end customers away from their monster Wolfs.

These are seriously expensive and luxurious units, and it is exciting to see that Passivhaus is such a big part of the story. Mike Ingui of Baxt Ingui does high-end Passivhaus because his clients love the quiet and the air quality. But also, since they are sharing walls with neighbors, the lack of dust and bugs coming through the party walls. Sometimes he doesn't even tell them he is doing Passivhaus; it is his luxury standard for everyone.

At Charlotte, it's part of the pitch. I hope that this is a trend and that people see the value in it.

We may not all be able to afford a 2-inch thick marble countertop or French wide plank flooring, but everyone can have the luxury of Passivhaus—and everyone should. As Poisson concluded in Green Building & Design: "We hope Charlotte of the Upper West Side’s energy performance, occupant comfort, and indoor air quality sets a new benchmark in multi-family residential design, scalable and repeatable anywhere."