Indeed, nonprofit developers investing for the long haul respond to a rigorous decision-making process that starts with the site. To give clients a financial kick to go green, William Kreager, FAIA, a principal at Mithun in Seattle, first takes a reductive approach, asking which green moves cost less than standard procedure. It might mean minimizing grading, stockpiling and reusing soil, and grinding up demolished paving for reuse as trench backfill. At High Point, an 800-unit HOPE VI project in urban Seattle, Mithun won a zoning variance to create a 25-foot-wide street with parking on both sides. The narrower street reduced the amount of pervious surface, made the street child-friendly by slowing traffic to one lane, and increased the amount of land for development and landscaping.

From there, Mithun looks for the low-hanging fruit—green ideas that have no additional cost premiums, from drought-resistant landscaping to low-VOC paints. Then it considers things that cost more now but will pay for themselves in the near future. “The choices depend on what's available locally and on what people recognize and value,” Kreager explains. For example, Energy Star appliances, whole-house fans, and compact fluorescent lighting cost a bit more and can be easily explained to clients and residents.

At High Point, the Seattle Housing Authority (SHA) also agreed that protecting the 1,000-plus trees planted in the 1940s would be money well spent, contributing immeasurably to the feel of the new neighborhood. An arborist priced every tree that was worth saving—some replacement costs were as high as $38,000—and the contractor signed off. The healthy trees that had to be taken down for construction were milled on site and reused. The SHA also splurged on higher R-value windows, Marmoleum flooring in the 36 homes designated for people with breathing problems, and a closed-loop hydronic heating system. “Things we'd love to have done but couldn't afford were a districtwide heating system with one central boiler, PVs on the roof for solar hot water, and gray water reuse,” Kreager says.

The green features accounted for roughly $1.5 million of High Point's $43 million rental housing budget. Based on the energy efficiencies alone, Kreager estimates the yearly utility savings at 20 percent, or $371 for a three-bedroom unit. Multiplied by 800 units, that adds up to a savings of nearly $300,000 per year, resulting in a five-year payback for a project that will be in the SHA portfolio for generations. “Our clients are tracking the costs, and the University of Washington is monitoring a lot of what we did there,” Kreager says, “so we'll have some pretty unimpeachable sources.”

green network

With their checklists firmly in hand, many architectural firms also keep their own records of construction cost premiums. It's the only way to understand how much these items truly cost and help clients make informed decisions. Hord Coplan Macht, a Baltimore-based architecture firm, asks contractors to segregate green items—Did they pay more for the paint or not? The firm often uses LEED guidelines as a starting point, even if it doesn't intend to certify the building.

“In the first meeting, we strive to identify the strategies we're trying to incorporate: Which credits will the client be able to get, and out of those, which ones are cost-effective?” says senior associate Monica Robertson, AIA, LEED AP. While there's no way around energy-efficiency upcharges, water conservation is easy on the budget. The firm routinely calls for low-flow toilets and showerheads, as well as small aerators inside the fixtures that increase water pressure while reducing volume—gestures that Robertson says reduce water use by 20 percent. The economical solution for exterior cladding, meanwhile, is often materials that use recycled content, such as metals, concrete, and masonry. “Fiber-cement siding has come down in cost quite a bit in the last couple of years,” she says. “And if we use masonry, we spec modules that are larger and less labor-intensive to install.”

Architects can do a lot of green good on a limited budget. At Dattner Architects, New York City, the emphasis is on things that are decidedly non-glitzy, such as installing more efficient boilers and tweaking the ventilation system to get better air quality. At the 85-unit David and Joyce Dinkins Gardens in Harlem, completed last December, a little design ingenuity overcame the air-quality issues of a double-loaded corridor. Rather than designing a common shaft that ties each apartment to an exhaust fan on the roof, each unit has its own fresh-air intake and fan. “If you're a nonsmoker and your neighbor is a smoker, the smoke won't contaminate your apartment,” explains principal William Stein, FAIA. “The cost of doing that was comparable to the traditional way of handling a vent and exhaust system, though it did involve addressing some regulatory issues to get it accepted.”

It's true that planning and code variances, along with a careful patchwork of funding, are usually needed to raise the green bar on affordable design. Case in point is the Roanoke–Lee Street Project in Blacksburg, Va., which won a 2007 Home Depot Award of Excellence for Affordable Housing Built Responsibly. Colin Arnold, AIA, LEED AP, who headed up the project as director of Community Housing Partners' Community Design Studio in Christiansburg, Va., credits its success to an integrated design process and generous financial support from nearly a dozen agencies and mortgage-assistance products. “We know how to build quality and performance; our goal is to find subsidies to fill the affordability gap,” Arnold says. The 14-unit, for-sale duplexes, with their colorful fiber-cement siding and metal porch roofs, cost $81 per square foot to build. That was accomplished with smart, low-cost measures such as advanced 2x6 framing and using energy modeling to ensure the efficiency of the electric heat pumps and ductwork. Site-development costs, which included rain gardens in lieu of a stormwater detention pond, brought the total project cost to roughly $98 per square foot.

Despite the financial and construction challenges, there's a growing political will to make green housing accessible to those who need it most. “What makes affordable housing a good area in which to pursue green is that these developers operate the buildings over a long term,” Waller explains. “There's so much more potential there than in for-sale housing for market-rate development, where the thinking tends to be more superficial because they're interested in green from a marketing point of view.”

Kreager agrees: “Green affordable housing makes so much sense, you wonder why for the last 80 years we've been ignoring it,” he says. “It's a cool time to be in building design.”