I recently read about an impressive, three-unit residential building in Portland, Maine through an article by Seth Koenig in the Bangor Daily News. After a little digging, I learned the project is spearheaded by Paul Ledman and Colleen Myers, as owners and developers, Mike White of Island Carpentry, the general contractor, and Kaplan Thompson Architects, the architectural firm. Ledman wanted a future-forward building and ended up with something that doesn’t use fossil fuels.
The building — located at 62 Cumberland Avenue — is connected to the electrical grid but powered by an array of 30 solar photovoltaic panels. On the roof, there’s also a string of 90 evacuated solar tubes that warm three hot water tanks, providing an estimated 70% of hot water needs among the three units.
Ledman indicates on his Eco Capital LLC Facebook page that they’ve produced 3,600 kWh of electricity in 1,500 hours, which covered heat, hot water, and appliances over the same period, leaving an administrative fee of $8.53 per month.
The Cumberland structure was built with heavily insulated walls with 9″ dense-packed cellulose and a 2″ layer of polyisocyanurate foam board, as well as a roof with 13″ of dense-packed cellulose and a 3″ cap of polyisocyanurate foam board, according to New Maine Times. Four air-source heat pumps are used for heating and cooling with ventilation from heat recovery ventilators.
Construction costs tally about $140 per square foot, according to Bangor Daily News, and the units are already under lease contracts as of September. So the building was built at or near standard construction costs, it has nearly zero utility bills, and the place is fully leased up — sounds like a multi-family model for the future to me.
[+] Take a peek behind the construction scene with Green Builder Magazine.
Credit: Seth Koenig, Bangor Daily News.
Article tags: Maine, net-zero, residential