Import Duties on Building Materials: What Contractors Need to Know

By Alex (COO) • • cost-guides

Import duties on windows, doors, and cabinets add 0-25%+ to landed cost. Here is what HTS codes, Section 301 tariffs, and first-sale valuation mean for your material budget.

Import Duties on Building Materials: What Contractors Need to Know

When you buy windows, doors, or cabinets that were manufactured overseas, the price on the manufacturer's invoice is not the price that clears US Customs. Import duties, freight, customs brokerage fees, and port handling all sit between the factory price and the price on your job site. Ignoring these costs — or miscalculating them — turns a good deal into a budget problem.

This guide covers the duty rates that apply to the building materials contractors most commonly import, how to read a Harmonized Tariff Schedule (HTS) code, how Section 301 China tariffs work, and what a realistic landed cost calculation looks like.

How Import Duties Work

Every product imported into the United States is classified under a Harmonized Tariff Schedule (HTS) code — a 10-digit number that determines the applicable duty rate. The duty is calculated as a percentage of the "customs value" of the goods, which is typically the transaction value (what you paid the manufacturer) under FOB or similar terms.

The Layers of Cost

Landed cost = Factory price + Export freight + Ocean/air freight + Import duties + Customs brokerage + Port/drayage fees + Domestic freight

For building materials shipped from China by ocean container:

Duties are applied to the customs value of the goods only, not to the freight cost — though some HTS categories use CIF (cost + insurance + freight) as the valuation basis, which is worth confirming with your customs broker.

HTS Codes for Common Building Materials

Windows

| Product | HTS Code | Base Duty Rate | |---|---|---| | Aluminum windows (residential) | 7610.10.0010 | Free (0%) | | Vinyl (PVC) windows | 3925.20.0010 | 3.3% | | Wood windows | 4418.10.0010 | Free (0%) | | Insulating glass units (IGU only) | 7008.00.0000 | 4% |

Note: HTS codes and rates are subject to change. Always confirm current rates with CBP.gov or your customs broker before ordering.

Base duty rates on windows are low — aluminum and wood at 0%, vinyl at 3.3%. The significant cost driver for China-origin windows is not the base rate but Section 301 tariffs, covered below.

Doors

| Product | HTS Code | Base Duty Rate | |---|---|---| | Wood doors | 4418.20.8030 | Free (0%) | | Steel doors | 7308.30.1000 | Free (0%) | | Aluminum doors | 7610.10.0010 | Free (0%) | | Fiberglass doors | 3925.20.0000 | 3.3% |

Again, base rates on doors are minimal. The country-specific tariff situation is where the real costs appear.

Kitchen Cabinets and Vanities

| Product | HTS Code | Base Duty Rate | |---|---|---| | Wood kitchen cabinets | 9403.40.9060 | Free (0%) | | Bathroom vanity cabinets | 9403.40.9040 | Free (0%) | | Freestanding furniture (cabinets) | 9403.60.8081 | Free (0%) |

Cabinets have 0% base duty rates. This has made direct-import cabinets attractive for contractors and builders for years — though the Section 301 situation changed the math considerably.

Section 301 Tariffs on China-Origin Goods

Section 301 tariffs, imposed beginning in 2018 under the Trade Act of 1974, added significant surcharges on a wide range of goods imported from China. Unlike base HTS duty rates, these are not permanent law — they are trade remedies that have been extended and modified through multiple administrations.

Current Section 301 Rates (as of early 2026)

Section 301 tariffs are applied in addition to base HTS duty rates. As of early 2026, the rates for building materials from China fall generally into these tiers (verify current status with your broker, as these have been subject to change):

| Product Category | Section 301 Tariff (China only) | |---|---| | Windows and doors | 25% | | Kitchen cabinets (wood) | 25% | | Aluminum products | 25% | | Glass products | 25% |

This means a container of wood kitchen cabinets with a $20,000 factory invoice, importing from China:

The Section 301 tariffs are the single largest duty line item for most building material imports from China. They are also the item most frequently misunderstood or overlooked by contractors getting their first factory quotes.

What Section 301 Does NOT Apply To

Section 301 applies specifically to goods of Chinese origin. Goods manufactured in Vietnam, Malaysia, Mexico, or other countries are not subject to Section 301 (though they may have their own trade issues). This is why many manufacturers shifted production to Vietnam and Southeast Asia in 2018–2020 — the duty differential made it economically compelling.

Origin rules matter: if a Chinese manufacturer assembles goods in Vietnam using primarily Chinese components and labor, CBP may still find those goods to be of Chinese origin under "substantial transformation" rules. A customs broker familiar with building materials can advise on specific cases.

Anti-Dumping and Countervailing Duties (AD/CVD)

Beyond Section 301, certain building material categories have active anti-dumping (AD) or countervailing duty (CVD) orders. These are separate from Section 301 and can add significant additional duties.

Wood Cabinets from China

Wood kitchen cabinets and vanities from China have been subject to AD/CVD orders since 2020 (USITC Investigation 701-TA-620 and 731-TA-1445). These orders resulted from findings that Chinese manufacturers were selling cabinets in the US below fair value and receiving government subsidies.

AD/CVD rates vary by manufacturer and are reviewed periodically. Companies not individually reviewed receive an "all-others" rate. In practice, AD/CVD on wood cabinets from China has been substantial — in some cases exceeding 100% of the customs value for certain companies.

For any cabinet import from China, confirming the applicable AD/CVD rate with your customs broker before ordering is not optional. It can completely change the economics of a direct-import purchase.

Aluminum Products

Aluminum extrusions from China have been subject to AD/CVD orders for over a decade. Aluminum windows and door frames that use Chinese extrusions may be subject to these duties depending on classification and origin determination.

Duty Rates by Country of Origin: A Comparison

| Country | Section 301 | AD/CVD (cabinets) | Base Rate (windows, vinyl) | Effective total (approx.) | |---|---|---|---|---| | China | 25% | Varies (0-100%+) | 3.3% | 28%+ before AD/CVD | | Vietnam | None | None currently | 3.3% | ~3.3% | | Mexico (USMCA) | None | None | Free | ~0% | | Canada (USMCA) | None | None | Free | ~0% | | Germany / EU | None | None | 3.3% | ~3.3% | | Malaysia | None | None currently | 3.3% | ~3.3% |

Mexico and Canada benefit from USMCA (formerly NAFTA) and effectively pay 0% or near-0% duty on most building materials, which is why some contractors sourcing international materials pivot to Mexican manufacturers for certain product categories.

First-Sale Valuation: A Legitimate Duty Reduction Strategy

For importers who purchase through a middleman or trading company rather than directly from the factory, there is a legal duty reduction strategy called "first-sale valuation."

Under first-sale, the customs value is based on the price paid at the first sale in the chain of commerce (factory to trading company) rather than the final sale to the US importer. If a trading company marks up factory goods by 20–30% before selling to you, declaring the first-sale value can reduce the dutiable value — and therefore the duty owed — significantly.

First-sale is legitimate but requires documentation: factory invoices, proof of payment at each stage, and evidence that the goods were destined for US export at the time of the first sale. A customs broker can guide the documentation process.

Realistic Landed Cost Example: Kitchen Cabinets from China

A mid-range kitchen cabinet set for a 200 sq ft kitchen, factory price $8,000 FOB Shanghai:

| Cost Component | Amount | |---|---| | Factory price (FOB) | $8,000 | | Ocean freight (LCL, shared container) | $800 | | Section 301 tariff (25% of $8,000) | $2,000 | | AD/CVD (assumes 10% rate, conservative) | $800 | | Customs brokerage | $250 | | Port handling + drayage | $400 | | Domestic trucking to job site | $300 | | Total landed cost | $12,550 | | Effective landed multiplier | ~1.57x factory price |

Compare this to a Vietnam-origin cabinet set with the same $8,000 FOB price:

| Cost Component | Amount | |---|---| | Factory price (FOB) | $8,000 | | Ocean freight | $900 | | Duty (3.3% base, no Section 301) | $264 | | Customs brokerage | $250 | | Port handling + drayage | $400 | | Domestic trucking | $300 | | Total landed cost | $10,114 | | Effective landed multiplier | ~1.26x factory price |

The landed cost difference on the same factory price: $2,436, or about 24%. This is a meaningful number on a single kitchen, and it scales across multi-unit projects.

What Changes When You Work with a Sourcing Partner

One of the practical advantages of working through an experienced sourcing partner rather than buying direct from a factory is duty and logistics knowledge. Factories are experts at manufacturing, not US customs compliance. They typically quote FOB prices and leave all import logistics to the buyer.

A sourcing partner familiar with the US market handles the HTS classification, customs broker coordination, and landed cost modeling so you know your total cost before committing to an order — not after the container clears the port. This is where working with a team like Buildtana adds material value on larger projects. If you are sourcing at scale, getting the duty math right up front is worth the conversation at /onboard.

Key Things to Confirm Before Any Import Order

1. Country of origin — Where the goods are actually manufactured (not just shipped from) 2. HTS classification — A customs broker should confirm; factory classifications are often wrong 3. Active AD/CVD orders — Check USITC.gov for active orders on your product category and country 4. Section 301 applicability — For China-origin goods, confirm current rate and any exclusions 5. First-sale opportunity — If buying through a trading company, ask your broker about first-sale 6. ISF filing deadline — Importer Security Filing (10+2) is required 24 hours before vessel departure; late filings result in fines 7. Freight terms — FOB, CIF, DDP each assign different responsibilities for freight and insurance; know which you are buying under

Common Mistakes Contractors Make

Using factory price as the budget number. The factory invoice is the starting point, not the delivered cost. Add freight, duties, and logistics fees — often 30–60% on top of FOB for China-origin goods — to get the real number.

Not checking for AD/CVD. This is the mistake that creates genuinely ugly surprises. AD/CVD can be assessed after the fact by CBP, and unexpected duties on a large shipment can be thousands to tens of thousands of dollars.

Accepting the factory's HTS classification. Factories often misclassify goods — sometimes innocently, sometimes to suggest lower duty rates. Your customs broker classifies based on the actual product and is liable for the filing.

Ignoring origin shift risks. Just because a product ships from Vietnam does not mean it was manufactured in Vietnam. CBP can challenge origin claims, especially in categories with active trade remedy investigations.

Not budgeting for delays. Customs holds, CBP exams, and port congestion can add 2–4 weeks to delivery. On time-sensitive projects, plan accordingly or have a domestic backup source.

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