NAICS Codes and Subsegments

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Industrial Patterns reference editions describe a defined US building-materials peer set: 46 six-digit NAICS codes organized into 14 subsegments across five structural segments. The Add-On Density Atlas extends the peer set by one additional code at the distribution edge, for 47 codes total. This page lists every code in the peer set, the subsegment it belongs to, and the segment it sits in.

The peer set is the same across the Operating Benchmarks (annual), Industry Structure Reference (census-anchored), and Add-On Density Atlas (annual) modules. A reader purchasing across modules sees the same firms, establishments, and codes from complementary angles — operating performance, structural condition, and geographic distribution — by construction.

The peer set isolates US manufacturing and merchant-wholesale activities that produce or distribute physical building materials — the inputs to a building. It deliberately excludes three adjacent activities. Construction firms (NAICS 23) are a different buyer set with different operating dynamics. Retail (NAICS 444, building-material retailers such as home centers) is too diverse for meaningful intra-segment comparison. Mining adjacency (NAICS 21231) is excluded for substantially different operating dynamics than manufacturing or distribution.

The codes are reported on the NAICS 2022 classification spine. Sources publishing on the prior NAICS vintage are mapped to the 2022 spine through a frozen crosswalk verified code by code.

Merchant wholesale of construction materials — the channel through which lumber, brick, roofing, other construction materials, and metal and mineral products reach builders and contractors.

• 423310 — Lumber, plywood, millwork, and wood panel merchant wholesalers
• 423320 — Brick, stone, and related construction material merchant wholesalers
• 423330 — Roofing, siding, and insulation material merchant wholesalers
• 423390 — Other construction material merchant wholesalers
• 423510 — Metal service centers and other metal merchant wholesalers
• 423520 — Coal and other mineral and ore merchant wholesalers  (Atlas only)

The 423520 code is included in the Add-On Density Atlas peer set but not in the Operating Benchmarks or Industry Structure Reference peer sets. CBP publishes 423520 with sufficient county detail to map honestly at the geographic level the Atlas works at, where the firm-level operating data underlying the other two modules does not separately distinguish it from the broader 4235 subsector.

Cement, ready-mix concrete, clay and glass products, lime and gypsum, and other nonmetallic mineral building products — the heaviest, most freight-bound and therefore most locally-served of the building-materials trades.

• 327110 — Pottery, ceramics, and plumbing fixture manufacturing
• 327120 — Clay building material and refractories manufacturing
• 327211 — Flat glass manufacturing
• 327212 — Other pressed and blown glass and glassware manufacturing
• 327213 — Glass container manufacturing
• 327215 — Glass product manufacturing made of purchased glass
• 327310 — Cement manufacturing
• 327320 — Ready-mix concrete manufacturing
• 327331 — Concrete block and brick manufacturing
• 327332 — Concrete pipe manufacturing
• 327390 — Other concrete product manufacturing
• 327410 — Lime manufacturing
• 327420 — Gypsum product manufacturing
• 327910 — Abrasive product manufacturing
• 327991 — Cut stone and stone product manufacturing
• 327992 — Ground or treated mineral and earth manufacturing
• 327993 — Mineral wool manufacturing
• 327999 — All other miscellaneous nonmetallic mineral product manufacturing

Sawmills, veneer and plywood, millwork, and engineered and other wood building products. Spans primary processing (sawmills, veneer) through secondary value-added (millwork, engineered products, containers).

• 321113 — Sawmills
• 321114 — Wood preservation
• 321211 — Hardwood veneer and plywood manufacturing
• 321212 — Softwood veneer and plywood manufacturing
• 321213 — Engineered wood member (except truss) manufacturing
• 321214 — Truss manufacturing
• 321219 — Reconstituted wood product manufacturing
• 321911 — Wood window and door manufacturing
• 321912 — Cut stock, resawing lumber, and planing
• 321918 — Other millwork (including flooring)
• 321920 — Wood container and pallet manufacturing
• 321991 — Manufactured home (mobile home) manufacturing
• 321992 — Prefabricated wood building manufacturing
• 321999 — All other miscellaneous wood product manufacturing

Architectural and structural metal fabrication, sheet-metal and plate work, and hardware — the metal building-products trades.

• 332311 — Prefabricated metal building and component manufacturing
• 332312 — Fabricated structural metal manufacturing
• 332313 — Plate work manufacturing
• 332321 — Metal window and door manufacturing
• 332322 — Sheet metal work manufacturing
• 332323 — Ornamental and architectural metal work manufacturing
• 332510 — Hardware manufacturing

Polystyrene and urethane foam building products — the smallest of the five segments by count. The Operating Benchmarks and Industry Structure Reference peer set includes one of the two codes (326150); the Add-On Density Atlas peer set includes both.

• 326140 — Polystyrene foam product manufacturing  (Atlas only)
• 326150 — Urethane and other foam product (except polystyrene) manufacturing

The Operating Benchmarks module reports the distribution of operating outcomes across the peer set on four metric families: margin behavior, labor elasticity, capital efficiency, and scale penalty. The Industry Structure Reference reports the structural condition of the same peer set across seven dimensions: population, size structure, concentration, entry and exit, geography, organisational form, and labour composition. The Add-On Density Atlas maps where the establishment universe of each code sits across the United States, with a five-year drift layer. Each module's methodology is documented on the methodology page and in the appendix of every edition.

Further reading: glossary of terms, edition catalog, methodology.