America’s outgoing mayors are leaving behind a green legacy. Whereas Michael Bloomberg spurred growth of parkland in New York and Antonio Villaraigosa championed public transit in Los Angeles, Boston’s Thomas Menino may be remembered most for spearheading net-energy-positive infill housing. In March 2011 Mayor Menino introduced the E+ Green Building Program to encourage regenerative multifamily development. Alongside that announcement he issued a challenge to private-sector teams to submit regenerative designs for three municipally owned lots, with development rights to the parcels at stake.
Photo © Silvia Illia-Sheldahl
Ribbon cutting at the most recently completed of these E+ demonstration projects took place in December. Located in the Woodbourne section of Jamaica Plain, the pair of 3-story townhouses was produced by Boston-based GFC Development and design studio Utile. The two units are now for sale, for $595,000 each.
The homes are forecast to produce 11 percent more energy than they consume through a combination of efficiency and renewables strategies. Prominent among them is a super-insulated building envelope, as well as a rooftop system in which photovoltaic and solar hot-water panels occupy the same area. With careful day-to-day management, the units may exceed performance expectations, Utile principal Michael LeBlanc notes.
The E+ challenge also included social and economic criteria, so that winning designs could serve as templates for infill elsewhere in Boston. In creating the Jamaica Plain townhouses, “we developed roofline options that allowed the plan to be oriented in a number of ways, while remaining capable of optimal solar harvesting,” LeBlanc explains. In addition to replicability, the project’s plunging roofline embodies an E+ directive that form follow sustainability, about which the architect says, “The specific focus of getting to below net zero provided a certain liberation from the more rhetorical approaches to context.”
Expression of performance impacts the interior design, as well. On the townhouses’ ground floor, the concrete slab is left exposed for thermal mass. And thanks to the thermally broken building envelope, south-facing windows are deeply recessed, which effectively shades the interior from thermal gain, while windows on shaded elevations are flush to the exterior. While prospective homeowners might consider filling those deep windowsills with potted plants, LeBlanc says the interiors aren’t intended solely for sustainability didacts. The sleek spaces, which include an upscale open kitchen and skylit master-bedroom suite, “balance the goals and aesthetic agendas of our office with those of an urban market with a wide range of tastes.”
Based on the success of E+ thus far, city officials are extending it into larger-scale multifamily buildings. An E+ Green Communities pilot program—a partnership of the Department of Neighborhood Development, Office of Environment & Energy Services, and the Boston Redevelopment Authority, with the Enterprise Foundation—has gathered proposals for developing as many as 50 apartment units and public amenities on a site in Mission Hill.