President-elect George Bush should substitute vouchers for low-income housing programs when he takes office next month, according to a report made public Monday by a conservative think-tank with close ties to Republican administrations.

"Housing vouchers are the best general method of assisting low-income Americans to obtain housing," says the report from the Heritage Foundation. "Since a voucher provides a family with a certificate of a given value, which can be supplemented, as desired, by family income, it gives low-income Americans the freedom to choose how much they wish to spend on housing and encourages tenants to shop around for the best available unit."Under the voucher program, the poor would receive government certificates redeemable for rent anywhere they want to live. Such a system, the report says, would help more than twice as many low-income families using the same amount of government resources.

The report, a chapter of a forthcoming book, was written by Peter J. Ferrara, a George Mason University law professor and former official at the Department of Housing and Urban Development. It said the Bush administration should propose funding in fiscal 1990 for 100,000 additional housing vouchers to replace low-income housing policies which subsidize the construction and operation of public and private housing projects.

Ferrara said the administration should restrict future housing construction for the elderly, the handicapped and Indians on reservations.

In his chapter, Ferrara said Bush also should push for sweeping changes in housing laws to enable hundreds of thousands of low-income families to become homeowners.

He said the president's objective should be to transfer 20 percent of all public housing units to tenant ownership or management by the end of his first term.

Currently, more than 1 million U.S. families live in public housing and the federal government spends some $15.4 billion a year on low-income housing projects, according to Ferrara.

"Turning residents into managers and owners gives them a strong personal stake in the properties and the incentive to improve maintenance and living conditions," he wrote.