Hillside Homes to Undergo Quake Study : Recovery: Inspections may call for code revisions and retrofitting, as structures on slopes warrant special attention.

A team of engineers and city building inspectors will start looking at scores of hillside homes above the San Fernando Valley this week and next in an effort to analyze the varying degrees of damage the buildings suffered in the Northridge earthquake.

The group’s conclusions will probably result in revisions to the city building code, including possible retrofitting requirements for existing hillside houses, a department spokesman said. The code’s current seismic-safety requirements are the same for structures on flat land and hills.

“We’re looking at common factors in the failure or damage that these buildings sustained,” said Nicholas Delli Quadri, a senior structural engineer at the Los Angeles Department of Building and Safety.

“It may be maintenance problems, it may be lack of (building frame) connectors that should’ve been there, it could be anything. . . . Based on that information will come back recommendations on what to change in the code,” Delli Quadri said.

The so-called subcommittee on hillside dwellings has compiled a list of 378 single-family homes on the Valley side of the Santa Monica Mountains between Studio City and Woodland Hills. Some sustained 25% damage and were green-tagged or deemed safe to occupy, and others were yellow- or red-tagged.

It’s unlikely the subcommittee will visit all the homes, Delli Quadri said. But the visiting group of engineers and inspectors hopes to sample enough to make comparisons, especially between similarly designed structures.

The list includes six homes on Sherwood Place, where quake victims Marc Yobs and Karen Osterholt lived, all of them on the down-slope side of the street, Delli Quadri said. (Yobs and Osterholt’s home is not listed among the six, probably because it was demolished, Delli Quadri said.)

City officials and private engineers have been studying earthquake damage for months in an attempt to learn from the 6.8-magnitude temblor and revise the city building code. But the subcommittee on hillside dwellings was only recently formed, at the suggestion of a Northern California engineer who was already serving on post-quake committee and felt they warranted special attention.

In a phone interview Monday, engineer James Russell said that on a flat lot a building’s side walls are rectangular in shape, while those on a hillside are triangular. “That shape difference means the (earthquake) forces are acting differently, and that’s a situation that needs to be resolved,” said Russell, who is based in Concord, Calif., and heads a statewide committee on residential retrofitting for the California Building Officials Assn.

Three people were killed in the collapse of hillside homes during the Jan. 17 quake, according to the county coroner’s office. In addition to Yobs and Osterholt, they included 5-year-old Amy Vigil-Tyre, whose family also lived in Sherman Oaks.