Los Angeles Mayor Eric Garcetti announced Monday a significant plan to address the city’s earthquake vulnerabilities — which would include building-retrofit standards that could impact thousands of structures.

Garcetti unveiled his Resilience by Design plan, which was put together by seismic experts who consulted with businesses, property owners and other stakeholders. Dr. Lucy Jones, a U.S. Geological Survey seismologist, led the development of the report.

“Los Angeles has always been an epicenter of seismic risk,” Garcetti said. “But we are taking bold action to make L.A. an epicenter of earthquake preparedness, resilience and safety. Instead of being complacent and then jarred into action by a devastating earthquake, L.A. is moving forward proactively with a comprehensive package of preparedness and resiliency measures to fortify our buildings, protect our water supply, and keep our telecommunications online when the ‘Big One’ hits.”

The biggest part of the plan is the requirement for owners to retrofit two specific types of buildings if they were constituted prior to 1980 — soft story and non-ductile reinforced concrete.

Soft story buildings are wood frame buildings where the first floor has large openings — often for tuck-under parking, garage doors or retail display windows. The requirement would be to retrofit within five years of a ratified plan.

Non-ductile reinforced concrete buildings (most were built before the implementation of a 1976 building code) are at risk, experts said, because some parts of the building, such as columns and frame connectors, are too brittle and break in strong shaking. Retrofitting improvements would be needed within 25 years of a ratified plan.

“We acknowledge that we cannot prevent 100 percent of the losses in an earthquake,” Jones said. “What we are trying to do is prevent the catastrophic collapse of our economy by addressing the biggest vulnerabilities. And if all of these recommendations are enacted, I believe that Los Angeles will not just survive the next large earthquake, but we will be able to recover quickly and thrive.”

The earthquake plan also calls for investments into fortifying the city’s water supply by developing an alternative water system for firefighting, protecting aqueducts that cross the San Andreas Fault, increasing water sources and developing a more resilient water pipe network. It includes a call for upgrades to the city’s telecommunications network to enable Internet and mobile connectivity after an earthquake — including creating partnerships between providers after disasters, protecting power systems at fault crossings, solar powered citywide Wi-Fi and fortifying cellphone towers.

Still, Garcetti acknowledged that most questions would surround the retrofitting, which could affect buildings in Hollywood and the Mid-Wilshire area. Which buildings, exactly, have not been determined.

“The Department of Building and Safety is committed to ensuring the success of this endeavor to making the city of Los Angeles a safer city and more resilient after a catastrophic event,” said Raymond Chan, Building and Safety general manager. “The department will establish a specialized unit dedicated to implementing the recommendations contained within this report. Services provided by this unit will include preparation of construction retrofit standards, easy-to-follow guidelines, public outreach workshops, and expedited plan review and inspection approval process.”

The department is also expected to come up with a list of possible buildings that fall within the retrofitting guidelines.

Local legislators are still reviewing the announcement, with City Councilman Mitch O’Farrell, 13th District, expecting to be briefed by the mayor’s office in the coming weeks.

“For sure — and we are talking this moment — there will be an earthquake within five, ten or twenty years from now,” City Councilman Tom LaBonge, 4th District, said. “To prepare is so important. It is a very significant investment in our housing.”

LaBonge added that he understands this plan could create some headaches among building owners, but he plans to work with owners and tenants to help, and that the city council would seek state money, as well.

“We need to come up with a solution for safety,” he said. “An earthquake may severely damage a building, but we don’t want it to pancake — that’s when you lose lives.”

LaBonge said he would ask City Councilman President Herb Wessen to schedule a robust discussion in council.

Building owners also are still wrapping their heads around the announcement.

“As one of the premiere organizations representing commercial building owners, BOMA Greater Los Angeles has appreciated the strong leadership provided by Mayor Eric Garcetti and Dr. Lucy Jones on seismic retrofit,” said Michele Ware, president of the Building Owners and Management Association (BOMA) of Greater Los Angeles. “The process has been open and collaborative, which is crucial to enhancing building resilience, protecting tenants and preserving a vital economic base in Los Angeles.”