EPA Indoor AirPlus SIP House Seattle WA

Location: Seattle, WA

Project Information

Project Type: Residential, > 3,000 sq. ft.
Manufacturer: Premier Building Systems
Builder: TC Legend Homes
Design Professional: TC Legend Homes
Year Built: 2017


High Performance: Yes
HERS/EUI Index Score:
ACH50 - Blower Test Results: 0.48
CO2 lbs./sq.ft./year:

Awards/Certifications: DOE Zero Energy Ready Home, ENERGY STAR Certified, EPA Indoor AirPLUS, Nat'l Green Building Standard

Install time (FAST), labor costs (minimal compared to other advanced framing options) and ENERGY efficiency. The goal for this project was to generate renewable energy, which is multiplied when the envelope is extremely efficient and much of the energy generated can go to other things (two electric cars).

• Layout: 4 bdrm, 4 bath, 3 fl + bsmt, 3,160 ft2
• Climate: IECC 4C, marine 
• Completed: December 2017
• Category: custom for buyer

• HERS Index: without PV 41; with PV 0
• Annual Energy Costs: without PV $1,400; with PV $100
• Annual Energy Cost Savings: (vs typical new homes) without PV $2,300; with PV $3,550
• Annual Energy Savings: without PV 11,500 kWh; with PV 21,650 kWh
• Savings in the First 30 Years: $156,700

Walls: R-29 6.5" graphite SIPs; fiber cement siding, mastic air sealing at all joints and panels, R-30 spray foam on rim joists.
• Roof: R-49 10.25" SIPs.
• Attic: Vaulted ceilings.
• Foundation: Slab on grade; 4" R-20 EPS under slab; ICF stem walls, R-23 perimeter insulation. Stained concrete floors.
• Windows: Triple-pane, low-e, argon-filled, wood frames; U=0.14, SHGC=0.35.
• Air Sealing: 0.48 ACH 50.
• Ventilation: HRV, MERV 13 filter.
• HVAC: Air-to-water heat pump, 4.5 COP.
• Hot Water: Air-to-water heat pump, 4.5 COP.
• Lighting: 100% LED, daylighting.
• Appliances: ENERGY STAR refrigerator and clothes washer. Induction range; condensing clothes dryer.
• Solar: 9.9-kW PV system.
• Water Conservation: 10,000-gallon rainwater storage for potable water.
• Energy Management System: Wireless PV and energy usage monitor.
• Other: 2 electric car charging stations. Low- or no-VOC products. No PVC. Passive solar design. Capable of 6 weeks off-grid for power and water.

DOE link to this project: EPA Indoor AirPlus SIP House Seattle WA

To explore other Zero Energy Ready Homes, visit the Department of Energy’s Tour of Zero page.


Affiliated Members

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