High performance with a waterview....
Goals. The lovely waterfront home in Manchester-by-the-Sea was designed by GA Crockett to embrace a blend of traditional 'shingle-style' and 'English cottage' vernacular while also achieving the more modern trait of exceptional energy performance.
Solution. ZED collaborated with GA Crockett to develop a building enclosure with construction details that respect the design intent while minimizing air leakage, thermal bridging, and heat loss. The latest in high efficiency all electric systems were then installed, and paired with a solar electric system to offset consumption.
Enclosure. The super-insulated building enclosure includes walls with 12" double stud wood frame construction, filled with dense packed cellulose. The roof uses 10" of mineral wool in the rafters plus 4" of polyiso exterior to the sheathing. On the walls, a liquid-applied membrane acts as the primary air barrier, while a taped ZIP system is used on the roof. The windows are triple pane with a simulated divided light achieving U-0.17 while remaining aligned with the target aesthetic.
Systems. Mitsubishi ducted air source heat pumps provide heating and cooling for the house, while a Zehnder ERV provides constant balanced fresh air with heat recovery. A 13.3 kW PV system helps off-set energy consumption, while two fireplaces with Bodart and Gonay Phenix Green sealed woodstove inserts and exterior vents for combustion supply air offer both ambiance and potential emergency back-up heating. A Stiebel Eltron heat pump hot water heater provides domestic hot water for the house. All lighting is provided by LEDs.
Result. The house uses 85% less energy than a comparable house built to minimum code requirements. Additionally, it produces more than 60% of its energy consumption on-site through photovoltaic panels.
SERVICES: CONSULTING PROJECT
- Energy Consulting
- Mechanical Design
EUI: 7.4 kBtu/sf/yr
Air Leakage: 1.2 ACH50
Better Than Code: 85%
Heat Demand 5.87 kBTU/(ft2yr)
Primary Energy 30.5 kBTU/(ft2yr)
Cooling Demand 4.08 kBTU/(ft2yr)
Heat Load 4.82 kBTU/(ft2)
Cooling Load 4.26 kBTU/(ft2)
12" Double-stud walls
Slab-on grad foundation
U Value: 0.14
Dense-packed cellulose, mineral wool, EPS, spray foam, and polyiso
R40 Above Grade Walls
Ducted air source heat pump (2.5 COP)
ERV (84% efficiency, 0.49 W/cfm)
Heat Pump Hot Water Heater