Island Housing Trust highlights energy-efficient apartment construction

Project builder Farley Pedler (center) led the tour. With him are Bea Phear, a member of the West Tisbury Planning Board, and Glen Hearn, a member of the West Tisbury Affordable Housing Committee and the Community Preservation Committee which provided leadership and funding for the project. — Photo by Tony Omer

The Island Housing Trust (IHT), a Martha’s Vineyard nonprofit that builds and manages affordable housing, hosted a recent tour of its Sepiessa II project at Clam Point Road in West Tisbury to highlight the money-saving, state-of-the-art energy-efficient design and construction techniques used to build three rental units in two buildings.

Sepiessa II is expected to be completed in September. The one-, two- and three-bedroom units sit on a lot next to four older apartments, Sepiessa I, built by the Dukes County Regional Housing Authority 18 years ago. The housing authority, which owns the land and now manages Sepiessa 1, will also manage Sepiessa II.

IHT executive director Philippe Jordi began the tour on May 27 with a description of the new low-nitrogen-producing septic system that will replace an older less efficient system and service both projects. The reduction in the nitrogen is particularly important because the properties border Tiah’s Cove off Tisbury Great Pond and the Martha’s Vineyard Land Bank’s 174-acre Sepiessa Point Reservation.

Project builder Farley Pedler of Drews Cove Builders led a group of more than 20 neighbors, builders, and homeowners interested in learning more about energy efficiency. Stepping into one of the unfinished apartments, he explained some of the energy-saving construction methods and materials being used.

Mr. Pedler said that building energy-efficient homes is a cost-effective way of building affordable homes. “The higher the R value, a measure of insulation efficiency, the less it costs to heat and cool a home and the more money is saved in the long run,” he said. “While the initial cost may be a little more, it is more than made up for in long-range savings.”

The three apartments total 3,184 square feet. Construction costs are about $810,000, or about $218 per square foot. Site development costs, including wells, the new septic system and electricity cost $115,000.

The well-insulated walls combined with triple glazed windows and doors create a super-insulated envelope, Mr. Pedler said. Blower door tests conducted by a certified home energy rater, in which a large exhaust fan is set in the door, are used to detect leaks in the buildings.

South Mountain Company, a West Tisbury design/build company that specializes in energy-saving construction, drew up plans that call for standard 2×6 studs filled with a tightly packed cellulose insulation, covered by an exterior air barrier of taped 2-inch thick foam. Half-inch exterior sheathing is then applied, a vapor barrier and the exterior siding.

He said the energy efficiency ratings for these building far exceed the requirements of the recently adopted stretch building code designed to increase the energy efficiency of new construction.

The buildings are so air-tight that they require mechanical heat recovery ventilators that maintain the flow of fresh air while conserving the heat from the exhaust air.

Air source heat pumps are used that deliver 150 to 300 percent more heat and hot water than the electrical energy they consume would produce using more conventional heating sources, Mr. Pedler said.

He said he felt fortunate that all of his projects over the last several years have been super insulated houses. His experience was on display during a question-and-answer session when several builders asked questions about specific construction issues.

The $912,000 Sepiessa II project received a total of $562,000 of West Tisbury Community Preservation Act funds, money from a three percent land tax supplemented by state monies from real transaction fees, $30,000 from the housing authority, $160,000 in Federal Home Loan Boston funding and a $160,000 loan from the Edgartown National Bank.