Green Buildings of San Mateo County

 Edminster-Bohner Home Renovation

Edminster-Bohner: Bay Windows

Project description:
The project was driven by the confluence of several environmental goals, along with a specific problem to be solved. The principal environmental goals were to improve the home's overall energy performance and durability; additional environmental goals were to improve daylighting and ventilation while enhancing comfort and aesthetics. The specific problem we needed to solve was a wood-framed pony wall that extended below grade, representing a long-term durability risk.

Summary of scope and initial goals:

  • Resolve durability risks, particularly below-grade wood-framed wall.
  • Improve energy efficiency.
  • Improve thermal comfort.
  • Improve aesthetics, solar access, and relationship to the outdoors.
  • Produce energy on site (install PVs).
  • Enlarge living room.
  • Accomplish all of the above in as resource-efficient a manner as possible and using environmentally preferable materials and methods.
Edminster-Bohner: Outside View


  • Energy Efficiency
    Old single-paned, aluminum windows were replaced with high-performance windows; entire uninsulated downstairs was upgraded with high-R-value insulation (upstairs addition was insulated when built); envelope was air-sealed; outdated, inefficient furnace and water heater were replaced with high-efficiency boiler and multi-zoned hydronic heating system. All appliances - washer, dryer, dishwasher, and refrigerator - are Energy Star-labeled. All hard-wired lighting fixtures are fluorescent.
  • Renewable Energy
    2.5kW photovoltaic system installed.
  • Water Conservation
    Old toilets were replaced with dual-flush, EPA WaterSense Toto toilets. Native and drought-tolerant plants used throughout landscape, including on living roof.
  • Indoor Environmental Quality
    Low-VOC finishes used throughout. Forced air replaced with radiant heating system, eliminating blowing particulates. High-efficiency, Energy Star fans were installed in baths and kitchen. Carbon monoxide monitors were installed on each floor.
  • Deconstruction/Demolition
    Usable wood scraps were retained for future projects. The old water heater was donated to another project. All remaining recyclable materials (primarily wood scrap, cardboard, and metals) were source-separated and recycled.
  • Material Selection
    • Roofing: steel in sloped areas for durability and clean run-off water, living roof over highly durable five-ply built-up roofing in flat area
    • Interior wall finishes: low-VOC paints and earth plasters
    • Decking: FSC-certified, highly durable tropical Machiche
    • Windows: energy-efficient, durable, steel-clad wood
Edminster-Bohner: Plans
Project Team:

Architects: Design AVEnues and OtherFish Architect, Berkeley, CA
Building science: 3-D Building Solutions
Mechanical design: Davis Energy Group
PV system: Sun Light & Power
Living roof: Bill Wilson, Mill Valley, CA
Builder: Pacific Circle Construction, Pacifica, CA
Owners: Ann Edminster & Hal Bohner