President Donald Trump’s 25% tariff on Canadian and Mexican goods will harm housing affordability in the United States, the National Association of Home Builders (NAHB) said in a statement over the weekend.

Previously, the association applauded Trump’s day-one executive order that urged government agencies to take action to lower the cost of housing and expand the housing supply. However, NAHB chairman Carl Harris said raising tariffs will have the opposite effect.

“More than 70% of the imports of two essential materials that homebuilders rely on — softwood lumber and gypsum (used for drywall) — come from Canada and Mexico, respectively,” Harris said in a press release. “Tariffs on lumber and other building materials increase the cost of construction and discourage new development, and consumers end up paying for the tariffs in the form of higher home prices.

“NAHB urges the administration to reconsider this action of tariffs,” Harris continued. “We will continue to work with policymakers to eliminate barriers that make housing more costly and prevent builders from boosting housing production.”

The tariffs are scheduled to go into effect at 12:01 a.m. ET on Feb. 4. Beginning then, Canada will be taxed 25% on imports, excluding energy. (Energy imported from Canada, including oil and natural gas, will be taxed at a lower rate of 10%.) Meanwhile, China will be taxed 10% on all imports.

Mexico, too, was supposed to incur a 25% tariff. However, on Feb. 3, Trump announced a one-month delay on that tariff, following a conversation with Mexico’s President Claudia Sheinbaum Pardo.