Josh Altman is predicting at least half the people who lost their homes in the Pacific Palisades won't rebuild there ... but they won't be moving far.

We got the celebrity realtor on Robertson Blvd in Beverly Hills and our photog asked him about the vibe he's getting from displaced Angelenos who had their homes burned to the ground in the Palisades Fire.

Josh says it's becoming clear to him 50% of families are never moving back to the Palisades ... with lots of folks looking to start over in nearby areas Brentwood, Santa Monica, Beverly Hills and Bel Air.

As Josh explains, the Palisades was a picturesque American town, home to a lot of families with children ... and he just doesn't see these folks moving back a couple years down the line, especially after their kids get settled in new schools.

Josh says he's already negotiating dozens of deals in the Palisades, where his clients are selling their lots to developers who will build new homes for new families.

The rebuilding process will take years, but there's another problem with moving back ... what happens if you're the first family back on the block and you're surrounded by construction.

Josh says the insurance costs are a whole other issue giving families pause about returning to the Palisades.

He says the tragedy has some folks fed up with L.A. and California altogether ... and he's hearing from folks who plan to move out of state or down to Newport Beach and Orange County.

The silver lining here is Angelenos banding together to help their neighbors ... and "Selling Sunset" star Davina Potratz says she's helping people find their next home, free of charge.

Davina and her Oppenheim Group realtors are also organizing fundraisers for fire victims.