Right now it appears David Horobin is building a dream igloo, instead of a dream house, in Alta Heights.

Few curious onlookers realize that the white foam blocks —  technically known as insulated concrete forms —  all over the place are a significant part of the Oxford-trained architect’s long-planned “green” home for his family in Napa.

“People think I’m a nut case,” said Horobin. “One woman said to me, ‘I can’t believe you’re building a house out of those.”

No stranger to green architecture, Horobin, who moved to the U.S. from England in 1978, has been designing with the environment in mind throughout his career. Many of the ideas and materials he’s used over the years are being incorporated  into the house he’s designed for his wife, Lynn, sons, Andrew, 16 and Chris, 12, and dog, Chelsea.

In fact, the project he and contractor Patrick Bentley of Bentley Construction and Concrete are building on Montecito Boulevard has so many interesting innovations, the Register has decided to follow the project over the next six months — the target date to finish is December so the family can celebrate the holidays in their new home — and pester Horobin and Bentley with questions about just what it means to build “green” in the year 2008.

Defining ‘green’

“Green,” Horobin said, “is the weaving together of many disparate, energy-efficient, resource-efficient, people-friendly practices in the design and construction of our buildings.”

 Horobin, who lost a home in the Los Gatos fire of 1985, said, “It means it will last and sustain the elements, including fire.

“When we moved here in 2001, we had a plan to buy a piece of property and build a house,” Horobin said. When they found a site, he developed the plans and broke ground in early June.

“One thing I believe is that if you affect people around you, (the design) should be sensitive,” Horobin said. In his case, it meant coming up with a plan for a hillside house that that wouldn’t destroy the view of his neighbor, who’s been living in her home for more than 40 years.

“I designed something to maximize the views for everyone,” he said. He even generating computer images of the proposed project as it would be seen from the deck of his neighbor’s home.

 The 2,700-square-foot house is built on a lot where there the slope descends 40 feet very quickly. “Laying the foundation on a graded hill is the slowest part,” said contractor Bentley. “We hit bedrock on the second day.”

 With the foundation in place, however, the innovative walls are going up swiftly. The building material is, indeed, blocks, which look like the environmentally unfriendly Styrofoam, but Horobin explained, are no relation (“We don’t ever want to use the word Styrofoam,” he said.) This, rather, is a form of polystyrene “which has no CFCs (chlorofluorocarbons),” he said.

The insulated concrete forms lock together like giant Lego blocks, and then are filled with cement, Horobin explained. Presto, you have a wall that’s insulated and fire-proof to boot.

“One of the biggest things for me about the house is I want to protect my family,” Horobin said. “The shell will be as fire-resistant as you can get.”

The house is being built from insulated concrete forms produced by Arxx Building Products, but the garage and retaining walls are using blocks that Horobin designed, called H-Forms.

Insulated concrete forms are easy to assemble, Horobin said. He and his family put together the retaining wall on the building site and would be helping raise the walls.  

“It’s the old concept of the owner/builder,” said Horobin. “Like the barn-raising, this brings it back to where it can be a family project.”

“It saves hours and hours of labor,” said Bentley.



The pool as part of energy efficiency

Another part of the plan — and one Horobin said had city of Napa Planning Department officials scratching their heads — is the innovative heating and cooling system the house will use: It’s all based on the swimming pool. This system — which will be the subject of an more in-depth article later  — use heat from pool water to warm the house in winter and then reverses to take heat from the house to heat the pool in the summer. The heating will be in the form of radiant heat, which, in Horobin’s design, it will be channeled into the ceiling. “The pool becomes part of the energy efficiency of the home,” Horobin said.

The first time Horobin used this technology — in 1984 —  it worked so well the pool became too hot to swim in, he said. But he’s been able to make adjustments.

“I believe that all the energy we need to heat and cool (our buildings) is in the ground and comes from the sun,” he said.

“It’s a true clean system,” said Bentley, who is using the same system in the house he’s building for his family and which is also being constructed from the insulated cement forms.

A family project

Bentley, Horobin and his family all met with the Register to discuss the project. “We’ve talked to the kids,” Horobin said, “Not many people get to build their own house — to design their own house and to use their own projects.”

 While the boys climbed around the building equipment and threw rocks, Lynn Horobin said, “We’re having a blast. The more we get into it and see the design, in my heart I feel like I’ve already moved in.”

“The most interesting client to work with is your wife,” observed Horobin. “I’m smart enough to know that the kitchen and interior stuff belongs to Lynn.”

“Good call,” said Bentley.

The Green House Project will run the fourth Saturday of each month. Forward questions for David Horobin or Patrick Bentley to Sasha Paulsen, spaulsen@napanews.com. Next month’s topic: Building green and friezes.