The maps are distributed to all affected cities, counties, and state agencies for their use in planning and controlling new or renewed construction.

When that happens, they are treated the same as new construction (a geologic investigation must be undertaken and the hazard mitigated before a building permit can be issued).

Single family wood-frame and steel-frame dwellings up to two stories not part of a development of four units or more are exempt.

However, the official geologic maps delineating the fault zones are used to help place a variety of structures on safe ground.

For example, the Belmont Learning Center, a large school complex in Downtown Los Angeles was complicated by the discovery of a surface fault on the property in 2002.

The Los Angeles Unified School District was required to remove a building that had been built directly atop the fault prior to its discovery.