Twin Peaks Passive House




Hosted by: Sandy Lawrence, Bellingham Bay Builders, and [bundle] design studio

  • Building Designer: [bundle] design studio
  • Contractor: Bellingham Bay Builders
  • Solar Installer: Ecotech Solar

Green Features:

  • Solar battery storage
  • High-performance building envelope
  • Ground source heat pump
  • Net positive energy
  • Passive House Certified
[bundle] design studio
[bundle] design studio

Photo Gallery


Twin Peaks Passivhouse + ADU is a resilient and eco-friendly home, designed to withstand natural disasters while also offering exceptional comfort and energy efficiency. Built to meet the rigorous standards of Passive House, the net positive energy performance of the home and ADU will help offset greenhouse gas emissions.

  • Walls over R-50
  • Lid over R-80
  • Blower door testing for minimal infiltration
  • Long east-west axis
  • Wide-open solar horizon
  • Solar easement to south (perhaps first in Whatcom County)
  • Three miles north of Bellingham city limit
Water Efficiency
  • Septic system cycles most of the water back into water table
  • Drip irrigation of gardens
Energy & Atmosphere

 Solar arrays produce more annualized electricity than consumption, even with a BEV + a plug-in hybrid!

Materials & Resources

 Carbon-fiber reinforced SIPs with hybrid wall a foot thick

Indoor Air Quality

 Continuous air exchange with heat recovery ventilation [HRV]

View all sites on the Green Home Tours & Talks website


Many thanks to our Event Sponsors:



Many Thanks To Our Energy & Green Building PROGRAM Funders and Sponsors!


Puget Sound Cooperative Credit Union
Puget Sound Cooperative Credit Union
Truly Electric & Solar
Instinct Builders
Ecotech Solar
Puget Sound Cooperative Credit Union
Puget Sound Cooperative Credit Union
Bellingham Bay Builders
Puget Sound Cooperative Credit Union
CAZ Construction