On the 2000 block of East York Street in Fishtown, a single-family residence has passed an important test - and received the rigorous passive-house certification.
Kate Czembor, an architect working at Kieran Timberlake, and David Kovach, a geologist who commutes to Trenton, bought the house on the condition that the builders and architects certify the new construction as a "passive house."
What is a passive house? It's a concept that relies on natural sources of energy for heating and cooling that can lower energy bills to well under $50 a month in all seasons. Often, a passive house is "net zero," meaning it generates all of its own energy. Architects train as passive house certified designers, as the couple's architect, Re:Vision in Center City, did.
Just this month, the two-story dwelling, which has a finished basement, received its certification from the Germany-based group Passiv Haus Projekte.
"We're waiting for our plaque from the organization," Kovach said, laughing. "It cost about 100 euros."
Their house is the first single-family residence in the city to pass the passive-house test, but not the first building. Onion Flats developed a multifamily project in North Philadelphia that was ultimately certified and listed on the International Passive House database (www.passivhausprojekte.de).
Belfield Homes is a three-unit townhouse project developed in partnership with a nonprofit community-service organization. Built in a modular factory with a solar array, the homes were the first certified passive house homes in Philadelphia.
Passive houses have a devoted following among environmentally friendly architects and builders. The idea is to make efficient use of the sun, internal heat sources, and heat recovery, rendering conventional heating systems unnecessary throughout even cold winters. During warmer months, passive houses make use of cooling techniques such as strategic shading to keep comfortably cool, according to the website Passipedia.org.
Internal surface temperatures vary little from indoor air temperatures, even in the face of extreme outdoor temperatures, Kovach said.
"The walls inside are about the same temperature as the windows and floors," he said. "The beauty of it is you spend more money on insulation, better windows, and air sealing. You save because your heating/cooling system is much smaller. Passive house makes economic sense."
Contractor and builder Mark Hutchinson and Re:Vision Architecture installed Intus brand triple-pane casement windows and a building envelope consisting of a highly insulated roof and floor slab, as well as highly insulated exterior walls, all of which keep desired warmth in the house or undesired heat out.
(Hutchinson pioneered the first "$100,000 home" with Postgreen Homes, a local developer.)
A ventilation system supplies constant fresh air, making for superior air quality, Czembor said.
"The problem with a lot of airtight construction is the houses are too tightly sealed, and that can create mold growth," she noted.
In their basement is the secret weapon, an "energy recovery vehicle" that modulates the cold- and warm-air exchange. The ERV draws warm air out of the bathrooms and kitchen and distributes it evenly throughout the house. The couple's GeoSpring water heater also uses heat-exchange technology.
The entire house runs on electricity, courtesy of solar panels on the roof. Even their LG washer/dryer is ventless.
Re:Vision designed around framing, concrete forms, and cladding to reduce cost and waste. It also installed Nest energy monitors and LED lights throughout.
That Czembor, an architect, purchased the house was a compliment, said Scott Kelly of Re:Vision Architecture.
Czembor and Kovach are cozy in their 1,300-square-foot home. She moved in from a 500-square-foot apartment and now enjoys a parking space. He moved from Bucks County and had to have a small yard.
They compromised on the new place, which totals 1,800 square feet, including the basement and a soundproof practice room for Kovach's band, the Bigness (he's the drummer).
"It's important to have outdoor space," Czembor added.
And the best part is being in Fishtown: "We know all our neighbors, we meet everyone on cleanup day, and everyone knows each other's names."