Green Buildings of San Mateo County

d'Souza/ de la Torre Residence

d'Souza / de la Torre Residence

This Belmont home is an amazing example of a home designed with sustainability as the guiding principal. The home is almost entirely self-sufficient. All electricity is provided by the photovoltaic (PV) system and water and room temperature are regulated by the solar thermal system. The home incorporates salvaged building materials, less-toxic and recycled building materials, energy-efficient appliances, sustainable wood, and lots of natural lighting.

The owners thought about the environment in every phase of the planning and building process. The family downsized from a larger home, taking inspiration from a book by Sarah Susanka, "The Not So Big House." Says Mr. d'Souza of his new home, "The reason we built the house in the city and paid the higher lot and permit-related building cost was to not tax the service infrastructure. The city already has a grid of services like sewer, power, garbage, recycling, transit, etc. It makes environmental sense to utilize the city's services and not burden agricultural and open space with infrastructure and pollution at the end of a new off-ramp."

The house is 1,823 square feet and is laid out to function as three separate sleeping units tied to a common service area (kitchen/laundry/living). Circulation spaces are maximized: the entrance to the kids' bedrooms is both laundry room and homework space; the stairwell is the library including a treehouse-like study at the master level. Tall ceilings with abundant natural light and open flow keep the small spaces from feeling cramped.

Green Building Details

  • Light tower and light-sharing design allows natural light to filter through the home
  • All fluorescent lighting, super efficient ConServ refrigerator, Energy Star appliances
  • Pise walls (constructed by ramming a mixture of selected aggregates, including gravel, sand, silt and a small amount of clay into place between concrete blocks)
  • Concrete countertops and flooring (concrete uses fewer resources than many other materials)
  • Recycled wood framing and elements, sustainable wood including bamboo flooring
  • Recycled automobile tires for roof, concrete and post-consumer glass countertops
  • Reused fixtures such doors from a school and light fixtures from a warehouse
  • Low-toxicity paint
  • Grey water system (all sink and shower water go into a tank to be used for irrigation)
  • Bicycle storage, proximity to transit and business district, designed within an already developed neighborhood (infill city design)
d'Souza - de la Torre Residence

PV System Details

Capacity of photovoltaic system: 2.5 kW AC (CEC rating), 3kW DC
Solar array: 20 BP 3150 panels
Annual amount of electricity generated by PV system: approximately 3.3 MWh

Solar Thermal System Details

Panels: 5 Heliodyne Gobi panelsM
Other equipment: two tanks, solar pump, floor heating, radiant space heating, Metlund hot-water-on-demand pump
Details: In addition to heating water for domestic, the system is a high-mass radiant heating system that uses an 18" deep sand bed under the house as a large storage reservoir. The heat is gained during sunny periods and is radiated slowly into the house during cooler temperatures. This is called the "Flywheel effect." The periods of heat gain and storage occur at periods that are not connected. The end result is a very stable temperature in the house due to the large thermal mass. The maintenance costs of the system over the lifespan amount to about 3-8% of the installed cost of the system depending on location of the installation. The maintenance required is the installation of new components- pumps, tanks and controls if they fail.

Project Team:

Architect: Arkin Tilt Architects
Builder: Ebcon Development
PV system: EcoEnergies
Solar thermal system: Declination Solar
Owners: Gladwyn d'Souza and Martina de la Torre