The Grand Award winner for the 2022 DOE Housing Innovations Award goes to this spectacular Positive Energy home in Bellingham, WA. Built by TC Legend the home is so energy efficient that the energy is uses, is generated by the solar in excess. So much so there is enough energy to power two electric cars and still have a supply of energy to share with the grid as needed.
“A net-zero house is appealing because of the money factor, and environmentally it’s a good thing, too. An energy-efficient house makes a lot of sense. Not being dependent on propane, natural gas, oil. The house itself has been fabulous, oriented in a way that gives a lot of natural light. The clerestory is terrific for daylight.”
The home impressively features the following key building elements:
- Walls: SIPs, R-29: 6.5" graphite EPS SIPs; house wrap; fiber cement lap siding
- Roof: SIP gable and shed roof: 10.25" R-49 (north) and 12.25" R-59 (south) graphite EPS SIPs, asphalt underlayment and asphalt composite roofing
- Attic: No attic, vaulted ceilings
- Foundation: Slab on grade: 4" R-20 EPS under slab; ICF stem walls 11.25" R-23.6
- Windows: Triple-pane, argon-filled, low-e3, vinyl, U=0.15-0.18, SHGC=0.46-0.34
- Air Sealing: 0.54 ACH50, all SIP joints sealed with double bead of mastic and tape. Windows have a double gasket. Whole-house aerosolized acrylic sealant.
- Ventilation: HRV to HVAC; timer, CO2 and humidity sensors for boost setting
- HVAC: Air-to-water heat pump with 50% central air handler, 50% radiant, 6.75 COP for cooling, 3.92 COP for heating. Passive heating design with exposed concrete floors
- Hot Water: Combo air-to-water heat pump for space and water heating, 50-gal, 3.92 COP; electric tankless back-up water heater.
- Lighting: 100% LED, passive and shaded vertical glazing
- Appliances: ENERGY STAR washing machine, dishwasher, refrigerator, exhaust fan
- Solar: 10.56-kW, 33 rooftop panels, micro inverters
- Water Conservation: EPA WaterSense-rated fixtures. Central manifold with PEX piping
- • Energy Management System: CO2 sensors, programmable HVAC system.
- Other: Low-VOC and recycled-content products. Aging-in-place design. EV charger installed
Download the full project profile here.
MODELED PERFORMANCE DATA:
- HERS Index: without PV 33; with PV -23
- Annual Energy Costs: without PV $600; with PV $-280
- Annual Energy Cost Savings: (vs typical new homes) without PV $1,200; with PV $2,150
- Annual Energy Savings: without PV 8,400 kWh; with PV 20,350 kWh
- Savings in the First 30 Years: without PV $48,930; with PV $86,550
View the award overview and project details here.