Quake-proofing L.A.’s ‘soft-story’ buildings

On Tuesday, the Los Angeles Department of Building and Safety will propose a plan for identifying which of the approximately 29,000 apartment buildings constructed in the city before 1978 might be potentially deadly wood frame “soft-story” structures. These buildings, supported by inadequate perimeter walls around open spaces on the ground level — such as carports — run the risk of collapsing during a serious earthquake, causing injury and death. In the 1994 Northridge earthquake, about 200 soft-story buildings were severely damaged or destroyed. That included the Northridge Meadows apartment complex, which killed 16 people when it fell.

The building code was changed in 1978 to require that all wood frame multistory buildings have stronger, better-braced walls on the ground floor, but there has never been a mandatory retrofitting of pre-1978 soft-story buildings. (Even in the wake of Northridge, such retrofitting was required only for those soft-story buildings changing use or being substantially remodeled.) The city doesn’t even have an inventory of these structures.

Building and Safety would create a database of these vulnerable buildings, which is the first step in the process of getting them retrofitted. Doing so will require a structural engineer to determine, by looking at Google maps and data, which of those 29,000 apartment buildings are probably soft-story and which are obviously not. The remaining buildings — and it could be an estimated 40% of the total — will require on-site inspection.

GRAPHIC: Retrofitting wood-frame soft-story structures

Making the list means a building is probably but not definitively soft-story. Further analysis by an engineer would be necessary to determine whether it is and, if so, how much — if any — retrofitting is necessary. Two council members, Tom LaBonge and Mitchell Englander, have proposed that the city look into how it could help landlords finance any mandatory retrofitting.

But we’re not there yet. Right now, the only thing being considered by the City Council’s Planning and Land Use Management Committee on Tuesday is whether to recommend that the council authorize the data collection. This is a smart step for a city in which officials have not shown much urgency about identifying and renovating buildings that could be disastrously damaged in an earthquake.

It’s a difficult challenge to retrofit a city. Just completing this survey of soft-story buildings will take inspectors about 14 months. So let’s get started.