Walk through the streets of New York City, and you’re immediately aware of the ethnic and cultural diversity of its people. Then look up – and study the buildings. You’ll see the same sort of diversity in the city’s housing stock. From 19th century tenement buildings to 21st century steel and glass towers, from single-family homes to high-rise apartment buildings, New York City has it all! But, despite their apparent diversity, what most of these homes have in common is their lack of energy efficiency and environmental mindfulness.
But that seems to be changing. Around New York City, we are seeing residential buildings being built or renovated according to green building standards. I recently had the opportunity to tour the first "row house" home built to Passive House standards in the borough of Queens.
Because the Sunset Green Home project is registered under the LEED® for Homes program, I generally write about LEED projects. So what is the difference between LEED and Passive House?
Façade of the Climate Change Row House
Both LEED and Passive House (which is also known as Passivhaus, as it originated in Germany) comprise a body of standards for sustainable building. In the case of LEED for Homes, the standards address many categories in addition to energy efficiency, including – among others – indoor air quality, the project’s location and links to its surrounding community, materials and resources used in its construction, and education of the homeowner. Passive House is a narrower set of standards that focuses primarily on energy efficiency, and seeks to minimize energy demand, heating and cooling requirements, and envelope tightness (air leakage). Passive House requires more of a project than LEED in terms of energy efficiency; LEED requires more of a project in terms of other important sustainability categories.
Google the two terms and you’ll find a lot of people opining on which of the two is “better.” Although I am a LEED AP Homes (credentialed by the Green Building Certification Institute), I don’t have a dog in this fight! I applaud anyone who voluntarily elects to participate in either one of the programs (emphasis on “voluntarily”…since current building codes are considerably less stringent than either of these two standards).
Back to the “Climate Change Row House” (so named by its owner, architect Thomas Paino) – the first multifamily row house home built to Passive House standards in Queens. Sunset Green Home and the Climate Change Row House have one thing in common: Flood zone requirements had a profound influence on both projects. Although Paino’s home was not flooded by Superstorm Sandy, which blew through New York City in October 2012, its living spaces needed to be elevated nearly four feet in order to comply with current flood zone requirements. Conventional house lifting doesn’t work when you have side walls in common with your neighbors. So Paino, an architect who has worked for two decades in sustainable architecture, got creative. He redesigned the home by raising each of the floors and keeping the walls intact. The façade was completely rebricked (the house had undergone a 1970s renovation and had a featureless white brick façade when Paino purchased it; while some have dubbed the Climate Change Row House one of the ugliest in Queens, its current façade is a vast improvement over what Paino started with).
The Climate Change Row House boasts a host of design features that make it one of the most energy efficient homes in the city.
Triple pane Schüco windows not only combat heat gain and loss through the building’s envelope, but they also provide extraordinary sound insulation. On my tour of the house, I was completely unaware of outside noise.
Triple pane Schuco windows with Argon gas for superior insulation
Passive House homes have minimal penetrations to the outside. So Paino's kitchen has a Best by Broan range hood that does not exhaust to the outdoors, but that instead uses two recirculating charcoal filters to eliminate cooking smoke and odors. And because Passive Homes do not have combustion appliances - so a fireplace and gas range were excluded - the kitchen features an induction cooktop by Bosch.
Bosch induction cooktop with Best by Broan recirculating range hood above
Passive Homes are so well insulated and sealed that they do not require much in terms of heating and cooling systems. All of the mechanical equipment for the Climate Change Row House fits into a small closet on the main floor, and includes a Heat Recovery Ventilator (HRV), which exhausts stale air and feeds preconditioned air into the house.
HRV exhausts stale air to the outside and provides fresh air to the indoor environment
A small Mitsubishi heat pump system is on hand if supplemental heat and cooling are required.
Mitsubishi heat pumps provide supplemental heating and cooling capacity
Paino cautions that "when you seal up a house, you have to be very aware of materials" to make sure that they don't "offgas" toxins into the indoor environment - particularly important given the tightness of the building envelope (click here to read my earlier article on the impact of 21st century building practices on indoor air quality). MDF doors from TruStile contain no added urea-formaldehyde resins. Paints contain no volatile organic compounds (VOCs), and the handsome wormy maple floor was finished on site using a UV sealing technology that creates a durable surface without any harmful offgassing chemicals.
TruStile NAUF MDF doors painted with no VOC paints in colors inspired by a western evening sky
The Climate Change Row House also collects rainwater from 50% of the roof into a cistern that was designed especially for urban homes. Paino uses the water to irrigate a sizable vegetable garden that he has planted in the double backyard formed by the home and an adjacent brownstone building that Paino also owns (and rents out to a tenant). He starts seedlings in the home's rooftop greenhouse. By growing produce on site from seed and irrigating with harvested rainwater, Paino reduces his household's consumption of fresh vegetables that must often travel great distances to reach the New York City market.
A rainwater harvesting system collects rainwater from 50% of the roof to water the home's sizable vegetable garden
A “Green Roof” garden, planted with several varieties of sedum, serves as a layer of insulation that keeps the rooms below it cooler in the summer than if the house were built with a conventional roof. The roof garden also absorbs rainwater, which means less stormwater runoff into the city’s already overburdened sewers. According to the New York State Department of Environmental Conservation, “In addition to being cited as a major source in one-third of all impaired waters, urban/stormwater runoff is noted as a major source of contaminants in 36% of all waters that experience lesser, but measurable, minor impacts to water quality, and a contributing source in nearly half (47%) of waters with minor impacts.” Paino’s design is an example of how urban dwellers can work to protect local waterways.
Six varieties of sedum comprise the home's green roof garden
Also on the roof is a solar thermal panel that generates the majority of the home’s hot water.
Solar thermal collector on the roof and hot water tank in the greenhouse below
Not only is the green roof attractive, but sitting on Paino's roof deck, one has a spectacular view of Manhattan just across the river.
Evening view from the roof of the Climate Change Row House
Because of the extent of the changes Paino needed to implement in order to conform with the flood codes, the City of New York designated Paino’s house as "new construction" rather than a renovation. The result of this designation? Paino told me that his ultra-efficient home would no longer be a candidate for Passive House certification by the Passive House Institute US (because the existing brick side walls would be maintained, Paino had originally designed the home to meet EnerPHit, Passive House Institute's renovation standard, which recognizes the challenges of refurbishing an existing structure and it less stringent in terms of envelope leakage). But that doesn't matter. The Climate Change Row House is still a superb example of how urban homes can be constructed for energy efficiency and minimal environmental impact.
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Want to learn more? The New York Times scooped me on this story! Here's what they wrote: "Easy on the Environment, but Not Necessarily the Eyes" (August 18, 2014)