The first LEED Platinum-certified multifamily building in Maine is the perfect defense against the Northeastern state’s harsh winters, promising savings on heating cost up to 40 percent.
Thornton Tomasetti led the engineering work and Fore Solutions, the green building consulting company acquired by Thornton Tomasetti in 2012, worked as the sustainability consultant and LEED for Homes Provider.
The 37-unit Avesta Housing-owned apartment complex was completed in spring 2012, with CWS Architects serving as the architect.
Located in the heart of Portland’s Arts District, Oak Street Lofts includes units that are 40 percent more energy efficient than the typical multifamily building. Heat and electricity costs for each studio apartment are expected to average about $58 per month, compared with $92 per month for a typical unit.
Thornton Tomasetti/Fore Solutions used energy modeling to analyze window glazing types, solar thermal water heating, and a heat recovery ventilation system. The firm also focused on envelope design to improve thermal breaks at the exterior wall, cellulose insulation for reduction of air infiltration and sound attenuation, and higher performing windows.
The entire construction system was planned from the outset to be both efficient and durable. Panelized, locally sourced wood wall framing minimizes waste, and all waste products generated were presorted for the most efficient recycling and disposal procedures. More than 60 percent of construction waste was recycled.
The 29,370-square-foot building, which includes 14,274 square feet of residential space, is highly insulated with a tight thermal envelope. The closely controlled building envelope is balanced by an energy-efficient indoor air management system.
The building site was deliberately selected for its convenient access to local amenities. City transit lines make more than 250 stops per day within a half mile of the building, and there are a variety of community resources nearby.