Aluminum tariffs open a wide portal for rising construction costs in the United States. Domestic production of the versatile metal has accounted for considerably less than 20 per cent of annual consumption in recent years so the U.S. government’s newly imposed 25 per cent import tax on all in-bound aluminum and steel products is expected to quickly flow to manufacturers and consumers.

The U.S. Window and Door Manufacturers Association (WDMA) is one of many industry associations voicing dismay. A temporarily threatened 50 per cent tariff on Canadian aluminum spurred particular worry given that Canada supplied about 75 per cent of the aluminum imports last year — 2.7 million tonnes, or nearly four times more than was produced in the U.S..

“Our members produce aluminum-clad windows of all sizes and types, and we all know that the commanding majority of aluminum that is utilized in the United States is coming from Canada.” advises John Crosby, the WDMA’s chief executive officer. “It’s going to have a downstream impact on the built environment. There’s no question.”

Similar to the automotive industry, some of the WDMA’s largest member companies operate in both Canada and the United States and have assembly processes that send products back and forth across the border two or three times before they are complete. Those manufacturers now face a 25 per cent surcharge on aluminum or steel components with each crossing. At the same time, Crosby notes that smaller players are less likely to have the resources to stockpile inventory ahead of the tariffs or the financial manoeuvrability to work out deals with the builders buying their products.

Prices could simply stabilize at the new higher level as a wider swath of prospective purchasers scrambles for the limited supply of untaxed U.S. aluminum. The averted threat (for now) of a 50 per cent tariff on Canadian aluminum allays the even greater inflationary pressure that would arise from obstructing such a large portion of the total market.

“With finite resources such as aluminum, if you create shortages, that will naturally escalate costs — manufacturing costs and, thus, downstream prices for construction companies that use aluminum products of any sort,” Crosby says. “In our industry, the small and mid-size window and door manufacturers are most subject to the winds of peril in the supply chain. We’re out there advocating for them, but they are largely defenceless when it comes to having to adapt to a market shock like that.”

Much will depend on how quickly trade disputes can be resolved, but Crosby suggests prolonged tariffs will particularly erode housing affordability, contrary to the federal administration’s 2024 election promise. Meanwhile, the Association of General Contractors (ACG) of America reports its members have already seen rising prices for key construction materials this winter due to market uncertainty, and predicts the imposition of tariffs will undermine development as rising costs delay or derail new projects.

“We all want to see more domestic suppliers of construction materials, but undermining demand for construction isn’t the right way to stimulate new domestic capacity,” maintains Jeffery Shoaf, ACG’s chief executive officer.

Both industry associations have presented these arguments to the U.S. administration, and WDMA is also planning an in-person foray to Washington, D.C. in April to talk to White House officials and members of Congress. Crosby also expresses some optimism for tariff exemptions, which are available under the same clause of the U.S. Trade Expansion Act that allows the President to invoke the tariffs — due to a purported national emergency — in the first place. However, that’s not considered a comprehensive solution.

“We have made our position to the Trump administration that we very much believe in free trade, especially with trusted partners to our country. We have been in contact with members of the administration, who, I would say, are sympathetic to our concerns, but aren’t necessarily the people making the final decision,” Crosby says. “The Trump administration believes tariffs are non-inflationary, and I think they are trying to test that. They are trying to test all American businesses, in particular manufacturing businesses, to either prove them right or wrong.”

Targets of the tariffs are also responding. Canada will apply a reciprocal 25 per cent tariff on designated U.S. imports as of March 13, 2025, valued at nearly CAD $30 billion worth of trade. That includes $12.6 billion worth of steel products, $3 billion worth of aluminum products and an additional $14.2 billion worth of goods manufactured in the U.S..

“The U.S. administration is needlessly disrupting an incredibly successful trading partnership. It is a completely unwarranted and unjustified move that will raise costs for Americans and Canadians alike,” says Canada’s Minister of Finance, Dominic LeBlanc.

Elsewhere, the European Union has announced a list of proposed countermeasures, representing €18 billion (CAD $28 billion) worth of trade, on U.S. imports. These are now open for consultation and could be imposed by mid-April.