President-elect Donald Trump has vowed to impose sweeping new tariffs on imports, leading his critics to argue that the plan will raise prices and spur inflation. …Nearly 10% of building materials used in residential construction are imported, according to the NAHB… and Canada probably accounts for the bulk of those imports. “Any tariffs that raise the cost of building products will have a detrimental effect on housing affordability,” says NAHB CEO Jim Tobin. ….A steep tariff on Canadian lumber would likely hit homebuilders the hardest—and could raise the prices of new homes, at least temporarily. But observers are skeptical that Trump would impose a steep, immediate tariff on such a fundamental raw material imported from a close ally. NAR’s Chief Economist Lawrence Yun said that it’s possible any tariff on lumber could be imposed over a ramp-up period to allow U.S. timber mills to boost production.