A Super-Green Piedmont Home
It could be the net-zero energy home of your dreams.
This is a view of the 4,462-square-foot house from the front, an impressive project.
Developer Ben O’Neill was looking to build a home for his own family, when he found the “virgin” lot at 53 Cambrian Ave. in a posh Piedmont zip code renowned for its schools. The quarter-acre of undeveloped land (almost unheard of in the 21st-century world of East Bay luxury real estate) became the tableau for an eco-friendly, net-zero energy modern manse with literal roots in the property.
Looking up from the street, the impressive 4,462-square-foot home, designed by Robin Pennell of Oakland’s Jarvis Architects, is a massive, energy-efficient structure with a three-story front elevation. With four bedrooms, three full baths, and two powder rooms, the home presents abundant living space, an enviable open floor plan, and is inviting in spite of its size. And it is perfectly temperature-controlled, season by season.
Every consideration of energy efficiency went into the planning and construction of this home. Along with Pennell and inSite Design’s Lauren Lee, the trio worked to identify and source specific materials that fit the overall net-zero energy functionality and ethos of the home, including its ambient flooring, photovoltaic solar, and greywater reclamation systems.
Starting from the foundation, up, O’Neill described the high R-Value, insulated thermal concrete forms used to create a nearly impervious vapor barrier that inhibits heat loss through transfer to the exterior. Custom-designed structural insulated panels, or SIPs, fitted with high-tech aluminum windows further insulate the “envelope” to create an environmentally drum-tight home.
“The key to keeping your home warm is creating a tight ‘envelope’ where heated air isn’t escaping,” said O’Neill.
“Not adding more insulation. Our goal was to create a net-zero, energy-efficient home using the vanguard of modern materials and technologies. Homes of this square footage require a lot of energy to heat and cool, especially houses with lots of glass.”
A 7.5-kilowatt solar system and ubiquitous, energy-sipping LED lighting reduce the home’s overall electric consumption, complemented by a gas water heater to augment a large family’s water usage. It is plumbed to the greywater reclamation system, of course.
“This home will generate as much power as it consumes over the year,” said O’Neill.
In keeping with the modern aesthetic of the home’s design, O’Neill turned to Oakland-based Alumatherm, a family-owned business specializing in commercial-grade aluminum windows. The company was tasked with creating custom windows for the building’s net-zero energy goal.
Utilizing argon gas and solar membranes, these “smart” windows regulate heat gain during the warm periods to assist in maintaining a consistent ambient temperature throughout the year.
O’Neill worked closely with interior designer Lee on just-right materials and finishes.
“We chose long-cured, manufactured French oak flooring designed to withstand heat from the ambient system,” said Lee. “Using this material allowed us to introduce the visual warmth of wood, while creating an efficient ambient system that ensures against gaps and warping, unlike solid wood flooring.”
The shape of the property, with its gentle slope and corner location, was designed to afford neighborhood and treetop views. Pennell used walls of glass to draw attention to the home’s two-story open interior and a spectacular custom chandelier.
“On the lower floors, you have finely finished spaces including a media room, wine cellar, and home office space,” said Pennell. “There’s an unimpeded flow of natural light and constant, ambient temperature.”
A protracted design and permitting process gave O’Neill time to harvest, cure, and re-purpose several mature redwood and cedars on the property. Re-imagined as beautiful, live-edge shelving, countertops, and exterior flashing, the redwood combines the home’s wild past to its modern future.
Designed with kids in mind, the top floor provides clear sight lines from an exterior patio and elevated level backyard perfect for keeping an eye out during playtime. A retractable NanaWall further integrates the outdoor and indoor living spaces seamlessly.
The cedars preserved from the site are re-imagined as benches surrounding a modern firepit, a meaningful reincarnation for the noble trees.
“We wanted to use all the existing elements the property had to offer,” said O’Neill. “Without wasting anything.”
53 Cambrian Ave., Piedmont
2 Powder rooms
3-car attached garage
Lot size: .24 acres (11,300 square feet)