President Donald Trump‘s proposed tax plan, which his administration is touting as the “biggest tax cuts in history,” might not be a net positive for home buyers, sellers, and owners, real estate professionals say.

The National Association of Realtors® swiftly came out with a statement critiquing the first draft of the plan released on Tuesday, which the group characterized as potentially harmful to the housing market.

“For over a century, America has committed itself to homeownership with targeted tax incentives that help lower- and middle-class families purchase what is likely their largest asset,” NAR President William Brownsaid in a statement.

But under the Trump administration’s plan, “current homeowners could very well see their home’s value plummet and their equity evaporate if tax reform nullifies or eliminates the tax incentives they depend upon, while prospective home buyers will see that dream pushed further out of reach,” he said.

The group pointed out that homeowners already shoulder 80% to 90% of the federal income tax burden. This could rise under the proposed plan.

Details of the plan were scant. However, the current proposal calls for doubling the standard deduction that taxpayers can use to lower their tax burden. That deeply diminishes the value of the mortgage interest deduction provided to help homeowners defray costs, and may discourage people from buying homes.

State and local tax deductions are also on the chopping block. This would hurt homeowners in the nation’s most expensive states the most, as they wouldn’t be able to deduct property tax payments from their federal taxes. And that could cost them hundreds, if not thousands, of dollars.

“It’s not going to have an immediate impact [on residential real estate], because demand is very strong for housing,” says® Senior Economist Joseph Kirchner. “What this will do is it will decrease affordability,” especially for the middle class.

Bigger standard deductions could overshadow mortgage interest deductions

Mortgage interest deductions are safe under the proposal. But doubling the standard deduction that Americans can take to lower their taxable income (and therefore their tax bills) could make that mortgage interest deduction much less valuable. That’s because homeowners can take it only if they forgo the standard deduction and itemize their deductions instead.

Under Trump’s proposal, the standard deduction would rise from $6,350 to about $12,700 for individuals and from $12,700 to roughly $24,000 for married couples filing jointly. This means single filers wouldn’t owe the IRS anything on the first $12,700 they earn, and the same for married couples’ first $24,000 in income.

“Doubling the standard deduction could severely marginalize the mortgage interest deduction, which would reduce housing demand and lead to lower home values,” Granger MacDonald, chairman of the National Association of Home Builders, said in a statement.

About 32 million homeowners took the mortgage interest deduction in 2014, according to the most recent data available from the NAR. It saved households an average $2,173. The deduction is good only on homes worth up to $1.1 million.

Writing off local and state taxes could become a thing of the past

The new tax plan might also stop letting folks write off their state, local income, and real estate taxes, which include property taxes. That’s expected to hurt West Coast and Northeastern residents the most, as they have some of the nation’s highest tax rates.

Those deductions can save folks thousands of dollars in some cases, says Roberton Williams, senior fellow at Urban-Brookings Tax Policy Center, a nonpartisan think tank based in Washington, DC.

In 2014, about 37 million households deducted a total of $178 billion in local and state real estate taxes, according to the NAR.

The deduction is popular with wealthier households. Only 10% of tax filers earning $50,000 or less claimed it in 2014, compared with 81% of those bringing home more than $100,000, the Urban-Brookings Tax Policy Center told MarketWatch.

Sorry, freelancers, home office deductions could be in jeopardy

People who work from home could also be hurt by the new plan, as home office deductions might vanish. These include insurance, utilities (like the ever-important power and Wi-Fi), repairs, and home depreciation, according to MarketWatch. The amount folks are allowed to deduct is based on the size of the dedicated workspace relative to the entire home.

These miscellaneous itemized deductions must be higher than 2% of workers’ adjusted gross income. That’s generally a household’s taxable income before deductions and exemptions are factored in.

So getting rid of the home office deduction “will have an impact on small businesses, startups, and consultants, who are all part of the middle class,”’s Kirchner says.

“These are all people who are potentially home buyers.”

Renters could be affected, too

It’s not just homeowners who could be affected by the tax cuts. Changes to the 1031 like-kind exchanges—what investors use to invest in commercial real estate—could affect how much money investors put into constructing new commercial real estate properties like apartment buildings.

That’s because the exchanges let investors, like hedge funds, defer the capital gains taxes on sales of investment properties (like rentals) and reinvest that money into new, similar property purchases. Changes could make the exchanges less profitable, leading folks to invest elsewhere. And that could mean fewer apartment buildings and higher rents.

“1031 like-kind exchanges help investors keep inventory on the market and money flowing to local communities,” NAR’s Brown said in a statement.

But not everyone is worried.

The cuts “wouldn’t generate enough tax revenue to be worthwhile,” says Jack Kern, director of research at Yardi Matrix, a commercial real estate data firm. Plus, he doesn’t believe too many investors would walk away from the more stable apartment development investments.

“You don’t need an office. You don’t have to have a warehouse,” Kern says. “But you do need a place to live.”