"It is very satisfying to be able to monitor the house's energy usage and see that far more energy is being generated than used."


Key Features

  • Walls: ICF, R-22 total: 11.25" ICF walls; composite wood siding.
  • Roof: Truss gable roof: coated OSB taped, full self-adhered membrane, 3/4" furring strips, 5/8" plywood, 2nd self-adhered membrane, solar PV shingles.
  • Attic: Unvented attic: 10" R-45 medium-density + 2" R-14 high-density spray foam.
  • Foundation: Insulated daylight basement: R-22 11.25" ICF, above-grade vinyl trim and siding, below-grade cementitious boards. 3.5" R-26 closed-cell spray foam under slab.
  • Windows: Triple-pane, argon filled, low-e2, vinyl frame, casement style, U=0.17, SHGC=0.19.
  • Air Sealing: 0.20 ACH50, spray foam under slab, liquid-applied flashings at all roughopenings and penetrations, spray foam under roof and at eaves.
  • Ventilation: ERV, CO2 sensors trigger higher speed. Boost settings in baths and kitchen. MERV 6 filter on fresh air intake, MERV 11 filter on supply to air handler, 76 SRE.
  • HVAC: Ground-source heat pump with one, 3-ton central air handler, ground-loop configuration with a 5.0 COP, AC variable speed compressor, 34 EER, rigid metal ducting.
  • Hot Water: Ground-source heat pump, 80-gal, 2.66 EF.
  • Lighting: 100% LED, motion sensors.
  • Appliances: ENERGY STAR refrigerator, clothes washer, ventless heat pump clothes dryer.
  • Solar: 11.752 kW, 13.5 kWh battery storage, rooftop shingles.
  • Water Conservation: EPA WaterSense toilets, central manifold with PEX piping.
  • Energy Management System: Sensors for CO2, temp, humidity. Tracking of PV, energy use, HVAC, ERV.
  • Other: Accessible floorplan, doorways. Low/no-emission paints, adhesives, sealants.

Building Specifications

Conditioned Area 3,481 ft2
Bedrooms 2
Bathrooms 2
Stories 3
Climate Zone 6A
Completion Date June 2021

Modeled Performance

  With PV No PV
HERS Index -16 27
Annual Energy Cost $300.00 $1,550.00
Annual Energy Cost Savings $5,500.00 $3,350.00
Annual Energy Savings 36,400 kWh 22,200 kWh
First 30 Years Savings $221,500.00 $135,300.00