"Homeowners will send us their electric bills because they didn’t expect them to be that low."


Key Features

  • Walls: 2x6, 16" o.c., R-21 total: advance framed; R-21 open-cell spray foam in cavity, house wrap, exterior lath, stucco.
  • Roof: Truss gabled roof: ¾" plywood, synthetic underlayment, asphalt shingles.
  • Attic: Unvented attic: 7" R-30 open-cell spray foam on underside of roof deck.
  • Foundation: Slab on grade.
  • Windows: Double-pane, argon-filled, low-e2, vinyl frame, U=0.29, SHGC=0.23.
  • Air Sealing: 0.63 ACH50, open-cell spray foam in walls and attic. Aerosol whole-house sealant.
  • Ventilation: ERV w/MERV 12 filter. Exhaust fans in baths and laundry, master bath fan has humidity sensor. MERV 8 filters in returns in hall and bedrooms. 16 SRE, 73 CFM, 52 Watts.
  • HVAC: Central air-source heat pump, 9.6 HSPF, 17 SEER, two-stage compressor.
  • Hot Water: Heat pump, 50-gal, 3.42 EF.
  • Lighting: 100% LED.
  • Appliances: ENERGY STAR refrigerator, dishwasher, exhaust fan.
  • Solar: 1.9-kW PV, 10-kWh battery storage, rooftop panels.
  • Water Conservation: Low-flow fixtures, central manifold PEX piping, recirculation pump, drip and predictive irrigation, stormwater management practices.
  • Energy Management System: PV tracking, battery usage timed to avoid peak rates.
  • Other: EV charging, low/no-VOC cabinets, carpets, flooring, paints, caulks, glues. In-duct hydrogen-peroxide air purifier.

Building Specifications

Conditioned Area 1,872 ft2
Bedrooms 2
Bathrooms 2
Stories 1
Climate Zone 4B
Completion Date June 2020

Modeled Performance

  With PV No PV
HERS Index 34 45
Annual Energy Cost $950.00 $1,300.00
Annual Energy Cost Savings $1,400.00 $1,000.00
Annual Energy Savings 11,100 kWh 8,200 kWh
First 30 Years Savings $55,900.00 $41,200.00