Most of the new rules are safety measures.

Among the new rules on the code books will be tougher building and design standards for homes in hillside areas where wildfires are a threat. The new codes include fire-resistant design requirements, including use of "ignition resistant" building materials.

Others require additional bracing in construction as a safety precaution for earthquakes and windstorms.

The old codes required that homes be designed to withstand 80 mph winds. The new codes set an 85-mph standard.

"The plan review process will take substantially longer," Ahrens warned. "We will have to look everything up. It won't be second nature."

San Rafael gets about 2,000 applications for building permits per year. The county gets 3,000.