Photos courtesy of Colbray Homes.
Colbray Homes built this one-storey new home in Mountain View County, near Sundre, Alberta, as part of Alberta Ecotrust's Getting to Zero program and Built Green. The envelope includes R-60 blown-cellulose attic and vaulted ceilings, 2x6 walls with R-20 batts and 2 inches of exterior rigid insulation, foundation walls with 2 inches of EPS and R-20 batts, and triple-pane windows. A ground-source heat pump heats and cools the whole home, with a wood stove as emergency backup only, plus heat-recovery ventilation and electric water heating. A rooftop solar array of 28.5 kW (57 x 500 W modules) is in the final EnerGuide file, with modelled annual PV production of about 28,167 kWh.
Airtightness improved from 1.57 ACH50 at the pre-drywall test to 0.87 ACH50 in the official EnerGuide file. With the solar array, that file rates the home at 0 GJ/year, 100% better than the EnerGuide reference house (123 GJ/year), and at NBC 9.36 Energy Performance Tier 4.
Sol Invictus was the energy advisor. Coefficient Building Science was the EnerGuide service organization.