Walls and Roof

Our approach was to balance the building envelope performance with PV production, program and cost. Understanding the PV capacity of the roof surfaces facing south, the occupants and the budget constraints provided the parameters for our design.

Subslab assembly

2 layers of 1.5 inch type IX EPS Insulation

Subslab R-value 14.0
Slab edge assembly

.5 inch cement based filler over 2.5 inch type IX EPS Insulation

Slab edge R-value 12.0
Foundation wall assembly

2 layers of 1.5 inch type IX EPS Insulation

Foundation wall R-value 14.0
Above grade wall assembly

Starting below the sill plate: continuous 1.5 inch sealant impregnated foam tape and 3.5 foam sill sealer, 2 x 6 wood stud walls insulated with dense packed cellulose, .5 inch zip wall taped covered by 1.5 inch foil face polyisocyanurate with taped joints, vertical 1 x 4 furring at 16" oc, and fiber cement siding.

Above grade wall R-value 30.0
Flat attic assembly

Loose fill cellulose insulation

Flat attic R-value 50.0
Roof Assembly

Asphalt shingles over 5/8" zip sheathing with taped joints.

Windows and Doors

Window Assembly:

Paradigm 8381 Vinyl Triple Pane

Average window U-factor 0.24
Solar Heat Gain Coefficient 0.23
Visible Light Transmittance 0.38

Mechanical Systems

Space cooling - Manufacturer & Model AOUA72RLBV
Space cooling - capacity 22 kW
Space heating - Manufacturer & Model Fujitsu VRF AOUA72RLBV
Space heating - capacity 25 kW
Domestic hot water - Manufacturer & Model State Hybrid Heat Pump Hot Water Heater
Domestic hot water - capacity 50 gal
Domestic hot water - efficiency 3 kW
Ventilation - Manufacturer & Model 475 Lunos E2, Panasonic Whisper Green
Lighting Manufacturer and Model
Lighting Efficiency
Mechanical Equipment Installation Details and Comments

Daily review by Owners Construction Representative, selected because he has knowledge of energy efficiency construction. Site visits made by Clear Result to perform quality control and blower door testing to evaluate airtightness.


Air Changes per hour, ACH50 1.06 ACH50
Air Changes per hour, CFM50