Most of New York's factories closed long ago, but plenty of local businesses use steel and aluminum, and they are beginning to feel the pain of President Trump's decision to impose tariffs on imports of the metals.

Companies building the skyline ever higher are being especially hard hit.

"Whether it's One World Trade Center, One Bryant Park, any of those iconic buildings that make up New York City skyline, those buildings have a tremendous amount of steel,” says JordanBarowitz, a vice president of the Durst Organization, a major owner and developer of residential and commercial real estate.

A 968-unit apartment complex the Durst Organization is building in Long Island City, Queens, offers a prime example of how the president's 25 percent tariff on steel imports is affecting New York's construction and real estate industries.

Barowitz says the cost of steel for the heating, ventilation, and air conditioning ducts alone has jumped to 70 cents a pound from 48 cents.

He says similar increases will ripple across the project, on everything from the structural steel beams and mechanical systems, to appliances and even steel countertops. He estimates the tariffs will add $10 million to $12 million to the project's cost, an increase of as much as three percent.

Barowitz says other developers are also being pinched, with potentially painful consequences for the city.

"There's fewer people building those buildings cause it's less viable, so it puts additional pressure on the housing market, drives up rents, drives up real estate prices, it's not a good deal for NYC,” he says.

The city's Economic Development Corporation says the tariffs also threaten employment in the five boroughs.

"When you put tariffs on the raw materials that go into manufacturing goods in New York City they fundamentally disincentivize companies from making things in the United States,” said president and CEO James Patchett.

Bronx-based Skyline Windows projects that its annual manufacturing costs will increase by a million dollars because of the president's 10 per cent tariff on aluminum imports.

The company uses more than two million pounds of the imported metal a year to make its windows.

"We can make a cheaper product, use less aluminum meaning our products would not perform the way we want them to, (but) I don't really think that's an option,” says president Matt Kraus. “It means that our 'material spend' is going to go up so it very well could have an effect on being able to hire more employees."

The city's manufacturers and builders are doing well right now, but experts said the longer the tariffs continue, the greater the threat becomes to the local economy.