Here in the world's technology capital, Silicon Valley's first newfangled "living roof" will start rising next year on -- of all things -- an affordable-housing project.

It might seem strange to some that a subsidized single-room-occupancy project with rents as low as $375 will be the Santa Clara County's first large-scale attempt at a green-building "vegetated roof," complete with soil and plants that absorb stormwater.

But the eco-friendly plan for the 59-unit Casa Feliz development in San Jose comes as no surprise to anyone familiar with First Community Housing's extensive green-building activities.

Celebrating its 20th anniversary this year, the downtown San Jose-based non-profit is on something of a roll these days, with projects totaling some 450 below-market rent units underway or soon to be. The award-winning developer has helped sharpen the cutting edge of environmentally friendly and energy-efficient multi-housing development, construction and operational technologies.

As First Community Housing's projects illustrate, affordable-housing and green-building can go hand in hand, even in a high-cost market like Silicon Valley. Indeed the developer's varying green technologies and strategies aren't just friendly to the environment and healthy for residents, they also help keep long-term operating costs down.

And not only can the lowered costs reduce rents and utility bills for modest-income tenants, they also allow FCH to pay off property debt sooner and launch additional housing production, noted Jeff Oberdorfer, the developer's executive director. While FCH utilizes all manner of recyled and eco-friendly materials, the emphasis on energy-efficient technologies and long-lasting materials are keys to the firm's long-term operational savings.

It's quite a challenge, especially given rising costs of development sites, basic construction materials and labor -- not to mention cutbacks in a state subsidy program encouraging solar heating and energy generation. That's especially discouraging to Mr. Oberdorfer and associates, given that FCH has successfully installed photovaltaic solar systems that produce sufficient energy to cover all the common-area electrical needs (and heat the pool in some cases) at four of its communities.

But Mr. Oberdorfer and company manage to keep producing affordable housing by employing numerous inter-related strategies: tapping available tax-credit and rebate-type programs incentivizing both affordable-housing and green-building; installing an increasingly standardized list of durable materials and energy-saving (even energy producing) technologies; and pursuing efficient arrangements with contractors.

Even FCH's site-location strategies help the environment -- and attract and serve tenants as well. All of its projects are along mass-transit routes, and the landlord provides free VTA Eco Passes to all its tenants, allowing for unlimited use of Santa Clara County buses and light-rail lines.

Veteran San Jose developers David Neale and John Brezzo formed FCH in1986. The firm has embraced a distinct emphasis on green building -- along with unusually striking architecture for affordable housing -- since Mr. Oberdorfer joined the firm in 2000. The portfolio is far from cookie-cutter in style or configuration; it includes family apartments, seniors housing, single-room occupancy projects, loft-type units, studio units, even mixed-use developments with ground-floor retail space.

Mr. Oberdorfer devised minimum environmental performance standards for materials finishes, operational systems and appliances. These include beating the state's Title 24 energy code by 15 percent, recycling 75 percent of construction waste and powering all lighting in common areas with renewable energy.

A sampling of elements incorporated into the 76-unit Betty Ann Gardens family apartments community in San Jose (which actually exceeded Title 24 standards by 25 percent): hydronic heating and cooling; low-flow water fixtures; all flourescent light fixtures; formaldehyde-free batt insulation; low-VOC paint; Eco-Star recycled content roofs; double-glazed windows and sliding doors.

First Community engaged a specialty consultant to track savings from the $310,000 photovoltaic system installed the 62-unit Murphy Ranch townhome community in Morgan Hill. The analysis estimated annual energy savings of 47.4 megawatts, translating to operational cost reductions of nearly $10,500. Factoring in about $155,000 in related rebates and grants, the savings should pay off the entire costs in less than 15 years.

While Mr. Oberdorfer hopes state officials will return the solar-assist subsidy to the higher level seen three years ago, he's encouraged that at least a few green-building costs have fallen somewhat. For instance, prices of cabinetry with no VOCs or formaldehyde have been declining, as is the case with the environmentally friendly natural linoleum First Community likes to use for flooring.

First Community also keeps costs down by negotiating so-called "design/build" arrangements with a couple of local general contractors intimately familiar with the developer's environmentally friendly projects: Branagh Inc. of Oakland and L&D Construction in San Jose.

"That helps keep the change orders to a minimum," and hence allows more investment into green elements when "contingency" funds go unspent, Mr. Oberdorfer explained.

As for the living roof, Mr. Oberdorfer expects to see more of them popping up around the valley. That's because First Community's due diligence analysis of Casa Feliz indicates the green roof will actually cost less long-term than installing off-site stormwater-management improvements that would have been required otherwise.

The developer discovered the newfangled roof should only increase the project's cost by one-half to 1 percent. "I'd like to include them in all the flat roofs we build from now on," Mr. Oberdorfer related.

Brad Berton is a freelance writer specializing in real estate. He is based in Portland, Ore.