Unlike its next-door neighbor, R-House, TED wasn’t originally planned to meet the exacting Passive House standard. Onion Flats initially won on the basis of its relatively straightforward proposal for a two-bedroom house with a three-story interior atrium. The building’s green bona fides came largely from four roof-mounted thermal solar panels and a 120-gallon water storage tank that Tim McDonald, a partner at the firm, says would have met nearly all of the home’s heat and hot-water needs.
After submitting the proposal, though, McDonald completed a course in the Passive House standard. Inspired, McDonald modified the original approach, ditching the tank and thermal panels in favor of a highly insulated, airtight envelope—the equivalent, he says, of shielding the house from the harsh Syracuse winter with a fur coat instead of a windbreaker.
“It was kind of crazy to effectively completely redraw the project and redesign the envelope, in particular, and the mechanical systems, but that’s what we did,” he says. “We made even more of a challenge of it by doing that midstream, but it worked in the end and it was really fabulous.” The owner decided to scrap the original plans for an elaborate storm-water management system, including a 1,000-gallon underground cistern and a landscaped rain garden—but both can still be added later.
Solar chimney: TED’s three-floor atrium creates natural convection, exhausting warm air and humidity from the space and eliminating the need for an air-conditioning system.
Steel cladding: The rain screen that serves as the building’s skin was made from painted steel panels by Pac-Clad (right). The low-maintenance material is durable and, at around $2.30 per square foot, relatively cheap.
Eco-friendly insulation: Recycled polystyrene foam-board insulation panels can be purchased for a fraction of what it costs to buy them new. Check the panels carefully for wear and discard any that are tattered or torn.
Design team: Onion Flats, Philadelphia
Size: 1,150 square feet