Roxbury E+ townhouses in Boston designed to produce more energy than they use

Boston-basedISAwon a competition organised by the city council to design the row ofthree-storey townhouses for a vacant plot in the Roxbury neighbourhood.

The project is a part of theE+ Green Building Program, a pilot schemeto develop energy-positive housing in the city. Named Roxbury E+, after the neighbourhood and this scheme, the houses havetimber frames are clad with both metal panels and taed wood.

A number of measures to save and produce energy werebuilt into the 185-square-metre houses, givingthe developmentapositive energy rating.

Roof-mounted solar panels and large windows that maximise natural daylight help to offset energy consumption,providing not just enough electricity and hot water for the housing, but a surplus.

"The energy output is targeted to exceed the demands of the occupants, with surplus to be sold back to the grid," said the architects.

Taps, shower heads and toilets have a reduced flow designed to minimise waterconsumption, whilegardens are planted with native and drought-tolerant species, intended to further reduce water wastage.

High insulation levels including triple-glazed windows contribute to the project'sLEED Platinum certification - the highest energy performance rating that can begiven to a building.

"As the site significantly slopes, the homes cascade down the hill to express the unique character of the site and to allow for ideal solar orientation," the architects said.

Photograph by Urbanica

The architects conceived the shape of the propertiesas a box, deformed to fit the sloping site. The stepped formadapts the terrace to the sloping site, while the mono-pitched roofs that slope away from the street achieve an optimum angle for the solar panels.

"The design process began with an elemental box - simple and affordable to construct, and predictable in its ability to be tightly air sealed and insulated,"the team said.

Each property has a two-storey-high inverted bay window, designed to maximisenatural light and ventilation, while playfully referring to theperiod features of the neighbourhood's traditional New England-style timber-framed houses.

"Roxbury is an eclectic neighbourhood with lots of character and charm," said the design team. "The architecture of the project introduces rich patterning through cladding components and formal gestures to create unique textures and visual rhythms."

Photograph by Urbanica

While three of the townhouses will be sold at market rate, one will be offered at 80 per cent of the value - a measure that intends to preservethe balance of the mixed-income neighbourhood.

"We hope the project will be a catalyst in helping to educate a new generation of local green-collar workers and stimulate the local economy and job opportunities," said the studio.

Photography is by Sam Oberterunless specified otherwise.

Project credits:

Design architect: Interface Studio Architects
Architect of record: Urbanica Design
Structural engineer: DM Berg Consultants
Civil engineer: C.L.G. Associates
MEP/solar: Engineering Design Build
Landscape designer: Boca Raton
LEED consultant: Urbanica Design
HERS rater: Conservation Services Group
Builder: Urbanica Construction

Massing diagram Massing diagram Envelope diagram Neighbourhood plan - click for larger image Site plan - click for larger image Floor plans - click for larger image Ventilation diagram and section