Girding homes against wildfire

New state building code regulations aimed at protecting homes in wildfires are expected to result in a modest increase in construction costs.

The new codes, which went into effect Jan. 1 in the 31 million acres of privately owned wild lands served by the state Department of Forestry and Fire Protection (Cal Fire), will become effective July 1 in municipalities served by their own fire departments. The regulations set higher standards for fire protection in new construction for windows, decks and outside walls.

The changes are expected to add between $1,500 and $2,500 to the cost of a new two-story, 2,500-square-foot house, experts said.

Ernylee Chamlee, chief of wild-land prevention engineering for the Cal Fire, said the aim was to protect against blowing embers’ lodging in walls and igniting houses. “We found that embers were getting stuck against walls,” she said. “It’s like a little barbecue there -- when the wind is constant, it feeds the coals.”

The new regulations, she said, also protect exterior walls from radiant heat and reduce the chances that flames will find areas to ignite.

They require exterior sliding glass doors, bathroom windows and any window near a doorway to be made with tempered glass, which is more resistive to high temperatures for a longer period of time than untreated glass.

For dual-pane windows, at least one pane must be made of tempered glass.

Another new requirement is that flashing, or metal sheathing, must now be placed as a barrier between an exterior wall and a wood deck. Gutters must be covered to reduce the accumulation of dry, flammable materials.

Though the regulations went into effect just three months after Southern California wildfires destroyed more than 2,000 homes, they were the result of years of collaboration between government and industry. “It’s an 18-month process to get code passed,” Chamlee said. “We had it ready a couple years ago but had to go through public hearings.”

Bob Raymer, technical director for the California Building Industry Assn., said builders were firmly behind the revised regulations.

“Yes, it does raise costs, but we had two goals,” he said. The changes were designed to make buildings fire resistive, he explained, while at the same time having a minimal effect on cost. “It may have taken longer to put the regs together, but this was the first major change to the code that everyone supported.”