Holderness House ZNE DER
Architectural design and construction: Garland Mill Timberframes
Integrated systems design (envelope and energy systems) and energy modeling for a private residence in Holderness. This existing lakefront home has been renovated to become a zero annual net energy building; it produces on site more energy (electricity) than it uses in an average year. A 7 kW solar electric system is grid-intertied, sending surplus energy to the grid on sunny days, and retrieving energy as needed at night and during cloudy periods. A ground source heat pump connected to closed loop vertical loop piping supplies heat. Solar hot water system provides the bulk of the domestic hot water.
This project takes up the challenge of retrofitting a conventional 70s ranch to become a highly superinsulated home. Stress skin foam panels are applied to the existing walls and roof. Wall and roof framing cavities are filled with closed cell spray polyurethane foam. Foam was added over the existing basement slab and a new floor was installed over the insulation. The basement was studded up on the interior (studs spaced off the concrete walls) and this is also filled with spray foam. House air tightness was improved 12X to 330 CFM50.
This home is one of the first examples meeting the Thousand Home Challenge.