The design for the Caterpillar House, sited on the softly rolling hills of the Santa Lucia Preserve, sought to accentuate a connection to the land. Having lived in a Cliff May home, the client came to the project with a love of modern ranch houses and looking for an environmentally-conscious response to a beautiful site. The Caterpillar House implements sustainable elements while exploring a contemporary version of the ranch ideals: massing that is low and horizontal, an open plan with a strong connection between indoor and outdoor spaces, and main living areas that center informally on the kitchen.

Connecting the home literally and figuratively to the site, excavated earth was repurposed for the construction of the walls. These rammed earth walls gently curve in response to the site’s contours and also act as a thermal mass, regulating temperatures from day to night. Three tanks close to the home proudly store rainwater and provide all of the property’s irrigation needs. Large south-facing glass doors open the main living area to a large covered contemporary porch and to an outdoor patio with sunshades that expand and contract to allow for a flexible entertaining area that responds to the client’s needs. The glazing, natural ventilation and operable shading also act as a passive heating and cooling system. Integrated photovoltaic panels enable the house to produce all of its own energy requirements without compromising the graceful curve of the low roof against the hill. 

The Caterpillar House was the first LEED Platinum Custom Home on California’s Central Coast.



Site and Landscape

  • At 2800sf, house is modest in size and half the size of the average house within the Preserve
  • Non-invasive plants
  • Compact development leaving the majority of the site undisturbed
  • 98% of site is permeable; impermeable surface run-off is directed to on-site catchment system
  • All hardscape is high albedo to reduce heat island effect


Water Efficiency

  • 27,300 gallon rainwater harvesting system
  • Native, drought-tolerant landscaping
  • Low flow bathroom fixtures


Passive Solar Heating and Cooling

  • Elongated East-West orientation maximizes the efficiency of passive heating
  • Exposed concrete floors and rammed earth walls form a thermal mass that absorbs heat from daytime sun and release it slowly during the cool nights
  • South facing glazing has .25 U-factor and .4 Solar Heat Gain Coefficient (SHGC) to maximize passive solar gain, but minimize harmful UV rays
  • Cross ventilation and ceiling fans for cooling
  • Shading trellises and long overhangs on south and west also reduce the need for a cooling system
  • Deciduous tress and retractable awnings provide summer shading on south-facing glazing
  • Air leakage minimized with blown-in, bio-based insulation
  • Insulated, recirculating hot water system
  • Exceeds by 49% the Title-24 requirements
  • EnergyStar rating for thermal bypass system


Energy Efficient Active Systems

  • Integrated photovoltaic panel system produces 115% of annual energy requirements
  • Zoned radiant floor heating system, designed to reduced distribution loss
  • Energy efficient appliances and lighting


Sustainable Materials

  • Low embodied energy materials (locally sourced and/or recycled content):
    • Rammed earth walls formed with soil from site and diverted from the landfill
    • 35% Fly ash content in structural footings and slab and 15% fly ash content in topping slab and landscape pavers
    • Reclaimed wine cork flooring
    • Recycled composite quartzite countertops
  • Sustainably harvested (FSC certified) wood framing and bamboo cabinetry
  • Efficient framing techniques: stud and joists spaced at 24” O.C., 2-stud corners and headers sized for actual loads
  • Reduced waste generation by 87% from typical construction


Indoor Air Quality

  • Natural ventilation: windows designed for cross ventilation
  • No forced air HVAC system
  • Low formaldehyde and low VOC materials used throughout
  • Exhaust fans in bathrooms & kitchen
  • Sealed garage from adjacent living spaces
  • Radon protection system
  • EnergyStar rating for indoor air package


Project Team

Contractor: Groza Construction
Landscape Design: Joni Janecki + Associates
Lighting Design: Revolver Design
Engineer: Yu Strandberg Engineering
Rammed Earth Consultant: Rammed Earth Works
Energy Consultant: Monterey Energy Group
Water Consultant: Earthcraft Landscape Design
LEED for Homes Representative: Michael Heacock + Associates
Photography: Joe Fletcher