Cities and counties throughout the state have used zoning overlays to preserve the affordable housing provided by mobilehome parks and protect residents from displacement.  Zoning overlays, special mobilehome park districts, or preservation zones establish mobilehome parks as the only permitted use for designated parcels. Petaluma and Cotati adopted Senior Mobilehome Overlay Districts in 2023 in response to threats from park owners to raise rents, convert to all-ages parks, or close the parks entirely in response to new rules previously enacted by the cities. These zoning overlays prevent senior mobilehome parks from being converted to all-ages parks and protect the affordability of this housing for seniors.  

Many jurisdictions within California have senior housing overlay districts, including Yucaipa, San Juan Capistrano, Huntington Beach, Ventura County, City of Ventura, and Santa Barbara. Some jurisdictions (like Ventura County and the City of Santa Barbara) have both mobilehome park overlay zones and senior mobilehome park overlay zones. The mobilehome park overlays prevent the redevelopment of mobilehome parks by limiting land uses, and the senior mobilehome park overlays apply solely to the senior mobilehome parks and specify that spaces in parks are designated for seniors.