A 27-story, 293-unit apartment tower adjacent to the former site of the World Trade Center in New York City, the Solaire became the nation’s first LEED-certified residential high-rise building in 2003. With features such as integrated photovoltaics, high-efficiency mechanical and cooling systems, a pesticide-free green roof, and an on-site wastewater treatment facility that alone cost a cool million to develop, it seems no expense was spared. Monthly rents are as high as $9,000.

Fortunately, the green multifamily arena has expanded to benefit consumers across all income brackets, with a number of noteworthy market-rate and affordable multifamily projects cropping up in cities throughout the country. Experts note three primary reasons for this trend: it enables developers and owners to differentiate their properties from existing buildings; even if they don’t immediately command higher rents, the buildings attract faster rent-ups with less turnover; and, says Michelle Desiderio, director of green building programs for the NAHB Research Center, “equity partners are increasingly requiring green certification because it fits into their larger corporate sustainability strategy.”

Desiderio oversees the National Green Building Standard (NGBS) program, established by the NAHB and the International Code Council in 2007 as a tool for guiding residential development. Desiderio reports that since 2010, 253 multifamily buildings have been certified under the NGBS, and more than 5,000 are in the pipeline. “Over the past year, multifamily buildings have represented the fastest growing segment of our certification program,” she says.

Recently certified, for example, was the Broadstone Citrus Village, a two- and three-story garden project containing 296 rental units in 17 separate buildings in Tampa, Fla. An infill site convenient to mass transit and shopping, the project features Grade 1 installed insulation, a passive radon-mitigation system, energy-efficient windows, and low-VOC paints. Units also include low-flow faucets and toilets, and Energy Star–rated appliances and light fixtures, which are becoming increasingly common in multifamily buildings.

While there are lingering misconceptions by developers that projects like the Broadstone Citrus Village still may be too expensive, these beliefs are vanishing as total project expenses shrink. “Roughly speaking, the total premium cost was in the range of $100,000 above code-minimum construction, plus the cost of certification,” says Kurt Robertson, development partner for Alliance Communities, which developed Broadstone Citrus Village. “Total ‘green build’ impact is less than half of one percent of the project budget.”

Increasing first-hand experience and decreasing costs will further fuel the green multifamily trend, according to John McIlwain, senior resident fellow for housing with the Urban Land Institute. “Depending on the sophistication of the design team, the total construction costs for LEED-certified buildings could actually be lower than the cost for a comparable noncertified building,” he says.

The LEED rating system informs the work of many multifamily projects, often with remarkable results. For instance, just a block from a new light-rail stop in San Francisco, Armstrong Place Senior and Family Housing contains a first-time home buyer affordable townhouse project, as well as an affordable senior housing building above street-level retail space. Designed by David Baker + Partners Architects, the four-level Department of Housing and Urban Development project is certified LEED Gold–certified and includes sustainable features such as solar collectors and stormwater-filtering bioswales. The project received a National AIA Housing Award, and it is a finalist for the 2012 Urban Land Institute Global Awards for Excellence.

Other developments are incorporating effective sustainable elements while foregoing certification. In Sacramento, the nonprofit Mercy Housing is developing 7th & H, a 150-unit, eight-story building with floor-level retail that will provide apartments for low-income and formerly homeless tenants. Scheduled to be complete in the fall, the infill project will include rooftop photovoltaic panels and thermal collectors that are expected to provide power to meet more than 50 percent of the building’s common energy consumption. By design, the building’s entire energy consumption is estimated to exceed California’s Title 24 requirements by at least 25 percent.

Altogether, the green multifamily trend certainly makes sense from a perspective of demographics, surveys suggest. As members of the 76 million–strong baby boomer generation retire, many want to downsize and prefer to be closer to urban amenities, preferring “maintenance-free lifestyles,” according to a 2009 National Association of Home Builders/MetLife survey of baby boomers. At the same time, their children and grandchildren are expressing less interest in traditional suburban living. With an estimated 80 million Americans, Generation Y is an even larger demographic than boomers. That its members are more tech-savvy and environmentally conscientious than their predecessors will likely push the momentum towards even more efficient, greener buildings. “In fact, Generations X and Y often find the rationale that a builder built a green building to save money on energy costs as offensive. They believe that the builder should do it because it is good for the environment,” says Desiderio. “This is very different from the baby boomers, where they value that ROI discussion.”

Of course, McIlwain notes that “green” is still a relative term, “until we get to net-zero buildings, which is beginning to happen. As requirements to disclose energy use become more common, the focus will ultimately shift from up-front certification to ongoing energy usage monitoring.”

“Maybe someday,” he adds, “developers will have to compete by how much energy their buildings produce.”

Click here to learn more about specific affordable housing strategies that work in a companion essay by Daniel Simons, AIA, of David Baker + Partners Architects. Ben Ikenson writes about green building and sustainability from Albuquerque, N.M.

This story has been updated since first publication to amend Michelle Desiderio's title and amend the photo and rendering credits for Mercy Housing's 7th and H development.