NAICS 321911

Overview

The North American Industry Classification System (NAICS) is the federal statistical standard for organizing business establishments to support collection, analysis, and publication of data on the U.S. economy. Adopted in 1997 and revised on a five-year cycle through the 2022 edition, NAICS was developed collaboratively by U.S., Canadian, and Mexican statistical agencies to improve cross-country comparability. ¹

NAICS 321911 covers establishments primarily engaged in manufacturing window and door units, sashes, and window/door frames from wood, including products where wood is clad with metal or plastics. Fabrication performed at the construction site is classified in the Construction sector, not in manufacturing. ²

What this NAICS covers

• Factory manufacturing of wood window units (complete assemblies). ²
• Factory manufacturing of wood exterior and interior door units. ²
• Production of wood sashes and wood window/door frames. ²
• Manufacturing of wood windows and doors clad with metal or plastics. ²
• Mass production of matched door/window components from wood stock. ²
• Manufacturing performed in a plant (not at the construction site). ²

Related NAICS and PSC codes

Type	Code	Descriptor
NAICS	321918	Other Millwork (including Flooring)
NAICS	332321	Metal Window and Door Manufacturing
PSC	5520	Millwork (includes wood door frames, doors, window frames, sashes)
PSC	5670	Building Components, Prefabricated (includes frames/sashes; wood items classify in 5520)

Classification boundaries and cross-references

• Metal window or metal door manufacturing is classified in 332321; wood or metal‑clad wood products remain in 321911. ²
• Fabrication performed at the building site is Construction, not 321911. ²
• Millwork such as wood moldings, trim, and stairwork falls under 321918, not 321911. ²
• Within Census classification guidance, 321911 is grouped under “Millwork” alongside 321912 and 321918. ⁴

Frequently asked questions

• What activities are in NAICS 321911?
  Establishments that manufacture wood window and door units, sashes, and frames in a factory setting—including wood products clad with metal or plastics—are classified in 321911. On-site fabrication belongs to the Construction sector and is excluded from this manufacturing classification. ²

• How does 321911 differ from 332321?
  321911 covers wood windows and wood doors (including wood products clad with metal or plastics). 332321 covers metal-framed windows and metal doors. The material primarily determines classification when products are factory manufactured. ²

• Where do wood moldings, trim, or stairwork fit?
  Those products are classified in 321918 (Other Millwork). In contrast, 321911 focuses on windows, doors, sashes, and frames manufactured from wood, including wood clad with metal or plastics. ²

• Is 321911 part of the Millwork grouping in Census program guidance?
  Yes. Census “Employer Categories” lists 321911 under the Millwork group alongside 321912 and 321918, reflecting related manufacturing activities within wood products. ⁴

• What is the current NAICS edition used for industry statistics?
  NAICS 2022 is the current edition. Federal statistical programs implement it on defined schedules; the U.S. Census Bureau began disseminating data on the 2022 basis with 2024 releases, with additional programs transitioning per the posted timeline. ³

Useful resources

• G2X — NAICS 321911 overview
• Census NAICS: 321911 definition, scope, and cross-references. ²
• Census guidance: Understanding NAICS (industry classification overview). ⁵
• Census: Implementation timeline for NAICS 2022 (program adoption schedule). ³
• PSC Manual (current): official product/service code definitions (e.g., 5520 Millwork; 5670 Building Components, Prefabricated). ⁶

References

1. U.S. Census Bureau — Industry and Occupation Classification (NAICS history, five-year revisions through 2022). https://www.census.gov/programs-surveys/cps/technical-documentation/methodology/industry-and-occupation-classification.html
2. U.S. Census Bureau — NAICS Sector 31–33 (includes 321911 Wood Window and Door Manufacturing; definitions and cross-references). https://www.census.gov/naics/resources/archives/sect31-33.html
3. U.S. Census Bureau — Implementation of the 2022 NAICS (timeline and status). https://www.census.gov/library/reference/code-lists/naics/2022/implementation-timeline.html
4. U.S. Census Bureau — Employer Categories and Corresponding Establishment NAICS Industries (Millwork grouping: 321911, 321912, 321918). https://www.census.gov/programs-surveys/esp/guidance/employer.html
5. U.S. Census Bureau — Economic Census: NAICS Codes & Understanding Industry Classification Systems. https://www.census.gov/programs-surveys/economic-census/guidance/understanding-naics.html
6. GSA/Acquisition.gov — Product and Service Code Manual (April 2025). https://www.acquisition.gov/psc-manual/all