Annapolis Net Zero

Goals.  As part of the home's full renovation and addition, the homeowner sought the consulting and mechanical design assistance of ZED to target exceptional energy performance and vastly improve the comfort of the house.

Solution.  ZED developed a building enclosure for both the renovated portion home and the new addition that minimizes air leakage, thermal bridging, and heat loss. The latest in high efficiency all electric systems were installed, and paired with a solar electric system to help offset consumption.

Enclosure.  The super-insulated building enclosure includes walls and roof both utilizing wood frame construction, filled with dense packed cellulose, plus 2" for the walls and 4" for the roof of polyiso exterior to the sheathing. A taped building wrap over the sheathing and under the polyiso acts as the primary air barrier. The windows are all triple pane throughout the home.

Systems.  A ground source heat pump provides radiant floor heating and ducted cooling for the house, while an energy recovery ventilator offers constant balanced fresh air with heat recovery. A 10.1 kW PV system helps off-set energy consumption. A Stiebel Eltron heat pump hot water heater creates domestic hot water for the house. Appliances are energy efficient, including an induction cooktop, and lighting is LED.

Result.  The house uses 85% less energy than a comparable house built to minimum code requirements. Additionally, it offsets nearly 100% of its energy consumption on-site through photovoltaic panels, essentially achieving net zero energy.