Tah Mah Lah

2021 All-Electric Awards – Honorable Mention

Location: Portola Valley

Building type: Single family home, new construction

Status: Completed

Size: 5,600 square feet

Completed: 2011

Owners: Paul Holland and Linda Yates

Website: www.tahmahlah.com

Contact: Linda Yates (linda@mach49.com)


Tahmahlah is an exciting summary of what building green can aspire to be, covering every dimension of sustainable design — energy, materials, water, waste, and habitat. The home is designed to zero net energy (ZNE) standards and, with addition of electric cars, is operating at near net zero. It has a super-efficient enclosure and 100% all-electric services: HVAC, domestic water heating, cooking, and clothes drying, fueled by both solar and geothermal sources of energy.

The home is fossil-fuel free and is exemplary for how residential buildings can help protect Bay Area air quality. Beyond net zero energy, the goal is for the family to have a net zero carbon footprint including transportation. Even the homeowners’ cars are electric. A major goal of this project is to inspire others to build green by debunking three myths: that green homes can’t be beautiful, that green buildings are twice as expensive, and that raising a family in a green home requires a drastic change of lifestyle.

Special Features

  • 27 kW solar photovoltaic system
  • Heat pump water heater
  • Geothermal ground source heat pump
  • Radiant heating
  • Induction cooktop
  • Daylighting and shading
  • Conscious siting of the home for maximum solar exposure
  • 100% recycling of all gray and black water + 35,000 gallon cistern (as a major consumer of energy, conserving and recycling water also reduces energy requirements)

Project Team

HKS/Hill Glazier Architects
Integral Group
MGM Construction
Evolution Construction
Ann Edminster
Bruce King
Peter Rumsey
Tom Klope
Patrick Kobernus

This content is password protected. To view it please enter your password below: