WASHINGTON The tax reform blueprint Republicans unveiled this week would upend U.S. housing policy if it becomes law.

Even though the plan maintains a special tax break for homeowners called the mortgage interest deduction, other provisions of the framework would basically make it useless for all but the richest homeowners.

This proposal will take away any tax benefit for owning homes for the vast majority of people who own homes, said Gregg Polsky, a tax expert at the University of Georgia.

Mortgage interest and property tax deductions cost the U.S. Treasury more than $100 billion a year in lost tax revenue, expenditures that are bigger in dollar terms than any other housing program. The federal government spends about $50 billion annually on housing assistance for people with low incomes, an amount that still leaves millions of people on waitlists for rental assistance. The mortgage interest deduction, meanwhile, overwhelmingly benefits homeowners with incomes above $100,000.