Which tariffs apply to construction materials
Based on AGC's guidance as summarized in September 2026, the Section 232 tariffs on steel, aluminum and copper remain at 50% for products made entirely or mostly of those metals. Products substantially made from them carry 25%, and some grid and industrial equipment containing them carries 15%.
Softwood lumber and timber carry 10%, with 25% on lumber and timber derivatives. A temporary 10% global surcharge imposed in February 2026 was scheduled to end in July, and broader tariffs imposed under emergency powers were struck down by the Supreme Court in February 2026. The Section 232 tariffs were not affected by that ruling.
Tariff rules change often. Check the current rates with AGC or the official source before you finalize a bid.
The trades with the most exposure
Anything built from metal is exposed: structural and miscellaneous steel, electrical (conduit, wire, switchgear, transformers), HVAC (ductwork, equipment) and plumbing (copper pipe, fittings, valves). Framing and finish carpentry contractors feel the lumber rates.
Six ways to protect your margin
- Get supplier quotes dated close to bid day, and note how long each quote is valid.
- Separate tariff-exposed materials in your estimate so you can see and explain the risk.
- Carry an escalation allowance on long-lead metal items delivered months after award.
- Ask for a price-escalation clause. AGC points to ConsensusDocs 200.1 as one option.
- Offer alternates, such as different materials or domestic sources, where the specifications allow.
- Re-check quantities. Tariffs magnify every overrun, so a precise takeoff matters more than ever.
How an accurate takeoff helps
When metals carry a 50% tariff, a 5% error in the steel, conduit or copper takeoff costs real money. Detailed, CSI-organized quantities let you price exposed items separately, adjust them quickly when a supplier re-quotes, and explain the number to an owner who asks why it went up.