Owners of historic properties  in unincorporated Los Angeles County would be eligible for property tax breaks if they agree to maintain the historic character of their buildings, under an ordinance the Board of Supervisors will consider Tuesday.

The ordinance would set up a Mills Act program, which “authorizes a reduction in real property taxes to private property owners who enter into a contract with a local jurisdiction for the preservation, restoration and maintenance of eligible landmark properties,” according to a board report.

The county Planning Commission OK’d the plan earlier this year.

Because the ordinance would reduce the flow of property taxes to the county – building owners who sign a 10-year deal wouldn’t be paying as much – county staffers are asking the supervisors to limit enrollment to six contracts per year for the first three years, with an annual cap of $300,000 and a total cap of $3 million in unrealized taxes.

As proposed by staff, eligible properties would include single-family homes valued under $1 million, two-family homes valued under $1.5 million and commercial buildings valued under $3 million. Commercial buildings wouldn’t be eligible until  year 3 if the supervisors adopt the caps.

A $982 application fee and a $543 contract execution fee apply.

The Mills Act, established by the Legislature in 1972, “is considered the single most important economic incentive program in California for the restoration and preservation of historic buildings by private property owners,” the staff report states.