Q + A with Development Officer Greg Payne of Avesta Housing’s Oak Street Lofts

The first affordable multifamily building in Maine to achieve LEED Platinum certification, Avesta’s Oak Street Lofts were designed and built by CWS Architects and Wright-Ryan Construction, with sustainability consulting by Thornton Tomasetti. The 37 artist-friendly apartments benefit from a solar preheat system for up to 85 percent of the building’s hot water, high-efficiency condensing boilers, energy recovery ventilators that return 76 percent of the energy in the exhaust airstream, a tight thermal envelope, panelized wood-wall framing to minimize waste, and locally-sourced wood.

Photo courtesy Avesta Housing.

Q: What are the energy costs compared to similar Avesta buildings?
A: The apartments are twice as efficient as a standard apartment. In the first year of occupancy, heat and electricity costs per apartment were just $46 a month, compared with $92 a month for a typical apartment. That’s a $20,424 annual savings for the entire building.

Photo courtesy Avesta Housing.

 Q: What did you learn during the LEED certification process?
A: We learned that location matters. LEED gives a lot of points for housing density and proximity to transportation and services. City transit lines make over 250 stops a day within a half mile of the building, and there are numerous restaurants, shops, and public services within walking or biking distance.

Photo courtesy Avesta Housing.

 Q: What features attracted the most notice?
A: We’ve received national attention for demonstrating that energy-efficient design not only lowers operating costs and creates a more durable building but also doesn’t have to significantly increase construction costs.

Q: What’s next?
A: We’d like to explore rooftop gardening or urban green space.

Learn more at Avesta Housing, Thornton Tomasetti, Wright-Ryan, and CWS Architects.

Q+A with Kris Folsom at Coastal Maine Botanical Gardens

In the year since it opened at the Coastal Maine Botanical Gardens, the 8,000-square-foot Bosarge Family Education Center—Maine's second commercial LEED Platinum building—has met its net-zero goal, which means it consumes no net energy and produces no carbon emissions over the course of a year. Designed by Portland's Scott Simons Architects in collaboration with Maclay Architects of Vermont, it is the first nonresidential building in Maine to reach net-zero status.

Photo courtesy Coastal Maine Botanical Gardens

Q: What are some of the building's most efficient features?
A: Bensonwood's prefabricated shell allowed the building to be built quickly during the winter months, and to the highest standards. The foot-thick walls have an efficiency rating of R-40, and the roof is R-60. Triple-glazed windows allow for passive solar gain in the winter and keep the building cool in summer. All this means the air infiltration is one of the lowest of any building in the state, making it very easy to heat and cool.

Photo courtesy Coastal Maine Botanical Gardens

Q: How did the building achieve net-zero energy status?
A: The building's 135 photovoltaic panels on the roof and 102 panels in a nearby field—installed by Allied Engineering of Portland and Energy Balance of Vermont—generated 55,184 kilowatt-hours in the past year. This is 30 percent more energy than it used, so it's actually an energy-plus building. At this rate, the system will pay for itself in 10 years.

Photo courtesy Coastal Maine Botanical Gardens

Q: What have you appreciated most about the building?
A: Not only is it being called "the greenest building in Maine," but it's a comfortable and lovely place to spend time when visiting the gardens.

Learn more at mainegardens.org and simonsarchitects.com.