Net Positive Solar SIP House Bellingham WA

Location: Bow, WA

Project Information

Project Type: Residential, < 3,000 sq. ft.
Manufacturer: Insulspan
Builder: TC Legend Homes
Design Professional: Powerhouse Designs
Year Built: 2023


High Performance: Yes
HERS/EUI Index Score: -20
ACH50 - Blower Test Results: 0.27
CO2 lbs./sq.ft./year:

Awards/Certifications: DOE Zero Energy Ready Home, ENERGY STAR Certified, EPA Indoor AirPLUS

Samish Solar

Sitting on a stunning 5-acre lot nestled into the woods and surrounded by wildflowers and berries, Samish Solar Home is an oasis for a growing family of mountain bikers and nature enthusiasts.

Along with this home’s solar array making it net-zero, it has an added level of resiliency with its 28,000-gallon rainwater cistern that supplies the house and its fire suppression system with water. The rainwater is filtered through a sediment filter, activated carbon filter, and UV filter to ensure it is fit for domestic use.


  • Overview:
    • 2345 sqft heated living space & 234 sqft unheated sunroom
    • 1600 sqft barn with 895 sqft loft
    • 4 bedroom, 3.5 bathroom
    • Net Zero Energy
    • 1st floor aging-in-place
    • Passive solar heating/cooling design
    • Insulation: R-29 walls & R-59 ceiling
    • Annual Energy Cost Savings: $2432
  • Mechanical:
    • Ventiliation: Fantech Hero 250 with built in HEPA filter. Built-in humidity, temperature, and CO2
    • Heating/Cooling: Chilltrix CX-34; hydronic radiant floor heating downstairs and a fan coil unit upstairs
    • PV: 10.8kW solar array with Enphase microinverters and battery ready
  • Selections:
    • Timber framed entry
    • Locally made cherry cabinets
    • Certified metal cool roof
    • Greenguard Gold Maple flooring
    • No/Low-VOC finishes
    • Fir doors and trim
    • Triple pane, Low-E coated, argon-filled vinyl windows

DOE project link:  Net Positive Solar SIP House Bellingham WA

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


Affiliated Members

BASF Corporation

Houston, TX
Insulspan SIPs

Blissfield, MI


SIPA Website Sponsors