Governor Gavin Newsom has signed a broad executive order that aims to make it easier to rebuild after the fires by suspending California’s costly and time-consuming environmental review process for homeowners and businesses whose property was damaged or destroyed.

The order is likely to be the first of several permit streamlining measures issued by state, county and city agencies in the wake of the devastating fires across greater Los Angeles.

Mr. Newsom’s three-page order, signed Sunday, covers all of Los Angeles and Ventura Counties and directs state agencies to coordinate with local governments to remove or expedite permitting and approval processes during rebuilding. The most significant piece is a waiver on permitting requirements under the California Environmental Quality Act — a landmark environmental law known colloquially as C.E.Q.A. or “See Qua.”

The governor also announced that he had suspended all permitting requirements under the California State Coastal Act for properties rebuilding after the fires.

California is one of America’s most difficult and costly places to build — a driving factor behind the state’s longstanding affordable housing shortage. Between state agencies and local land use commissions, the process of developing buildings, from office complexes to subsidized rental complexes, is longer and more expensive than in almost every other state.

Of all the hurdles a project can be subjected to, few are more difficult and time-consuming than C.E.Q.A. The law often requires developers to fund in-depth environmental studies on a project’s potential impact on everything from local wildlife to noise, views and traffic. Groups who oppose a particular development often use C.E.Q.A. lawsuits to try to stop them. This can add years even to small projects.

While the state’s powerful environmental groups are fiercely protective of any attempts to amend C.E.Q.A. or the Coastal Act, the laws are routinely suspended in emergencies and for large projects such as sports stadiums.

Still, Mr. Newsom’s order was unusually extensive. For instance, after other disasters C.E.Q.A. suspensions have typically required rebuilding property owners to show they tried to comply with the law, even if they weren’t subjected to it. The order announced Sunday is a full waiver: For anyone rebuilding after the fires, C.E.Q.A. is effectively gone.