NAICS 238220

Overview

NAICS 238220 covers specialty trade contractors that install, alter, and service building plumbing and mechanical (HVAC/R) systems. Typical scope includes interior plumbing fixtures and piping; gas lines; boilers, chillers, furnaces, and heat pumps (including geothermal); ventilation and ductwork; refrigeration; fire sprinkler systems; and solar-thermal water/space-heating equipment. Work spans new construction, retrofits, maintenance, and repairs. In federal facilities, this code is used for whole-building HVAC replacements, IAQ and energy-efficiency upgrades, plant equipment overhauls and controls integration, and plumbing rehabilitation in owned or leased space. Boundaries: site utilities such as water and sewer mains are classified under NAICS 237110, while electrical power distribution and low-voltage wiring performed independently of HVAC/plumbing fall under NAICS 238210. Contractors here may serve as primes or subs on design-bid-build or design-build projects, coordinating with general contractors and commissioning providers. ¹

What this NAICS covers

NAICS 238220 includes contractors whose primary business is installing and servicing building plumbing, heating, ventilation, air-conditioning, and refrigeration systems. The scope spans new work, additions, alterations, maintenance, and repairs, and encompasses mechanical trades performed inside buildings or integral to building mechanical systems. ¹

• Plumbing systems: interior potable water, DWV piping, fixtures, and related equipment.
• Heating systems: boilers, furnaces, hydronic/radiant heating, steam and hot-water distribution.
• Air-conditioning and ventilation: central A/C, heat pumps, air handlers, fans, and ductwork.
• Refrigeration systems: building refrigeration equipment and associated piping/service.
• Gas line installation within buildings serving appliances and mechanical systems.
• Ductwork installation for HVAC, including sheet-metal fabrication and fittings.
• Fire sprinkler system installation and related service activities.
• Solar-thermal heating systems for water or space heating.
• Steam fitting/mechanical piping tied to building HVAC and plumbing.
• Life-cycle services: change-outs, retrofits, seasonal service, PM, and repairs.

Related NAICS and PSC codes

Adjacent and commonly paired classifications used with NAICS 238220 in federal procurement:

• NAICS 238210 — Electrical Contractors and Other Wiring Installation Contractors; often paired for feeders to mechanical equipment, controls wiring, and low-voltage systems when contracted separately. ²
• NAICS 237110 — Water and Sewer Line and Related Structures Construction; used for exterior/site water, sewer, and related utility work outside the building footprint. ³
• NAICS 333415 — Air-Conditioning and Warm Air Heating Equipment and Commercial and Industrial Refrigeration Manufacturing; applicable for equipment-only procurements. ⁴
• NAICS 423730 — Warm Air Heating and Air-Conditioning Equipment and Supplies Merchant Wholesalers; for distribution/supply buys of HVAC equipment and parts. ⁵
• NAICS 221330 — Steam and Air-Conditioning Supply; relevant for district energy (steam/chilled water). ⁶
• NAICS 541330 — Engineering Services; covers mechanical/plumbing design, studies, and commissioning support as professional services. ⁷
• NAICS 561210 — Facilities Support Services; for integrated O&M contracts that include HVAC and plumbing. ⁸

Common PSC codes paired with building mechanical/plumbing work:

• PSC J041 and PSC J045 — Maintenance, repair, and rebuilding of HVAC/R and plumbing/heating equipment. ⁹
• PSC N041 and PSC N045 — Installation of HVAC/R and plumbing/heating equipment (non-construction). ⁹
• PSC 4110, PSC 4120, PSC 4130, PSC 4140 — Refrigeration, A/C, and air-moving equipment/components (supply buys). ⁹
• PSC 4510, PSC 4520, PSC 4540, PSC 4610, PSC 4630 — Plumbing fixtures, heating, waste-disposal, water purification, and sewage treatment equipment. ⁹

Frequently asked questions

• When should I choose NAICS 238220 instead of NAICS 238210?
  Use NAICS 238220 when the primary scope is building plumbing, heating, ventilation, air-conditioning, or refrigeration installation/servicing. Choose NAICS 238210 for standalone electrical distribution, wiring, or related electrical systems separate from mechanical/plumbing scope. ¹

• Are exterior water or sewer utility lines covered under this code?
  No. Exterior/site water and sewer mains and related structures outside the building footprint fall under NAICS 237110, not NAICS 238220. ³

• Does NAICS 238220 include fire sprinkler system installation and service?
  Yes. Fire sprinkler installation and related services are included within NAICS 238220 as building mechanical/plumbing specialty contracting integral to building systems. ¹

• Can I use NAICS 238220 for equipment-only purchases with no installation?
  Typically no. Equipment-only buys are classified under manufacturing or supply codes (for HVAC/R equipment, see NAICS 333415). NAICS 238220 is intended for installation and service work rather than product procurement. ⁴

• Can minor HVAC controls wiring be included under NAICS 238220?
  NAICS defines industries, not contract scoping rules. Agencies may bundle incidental related tasks on mechanical projects, but whether controls wiring stays under NAICS 238220 is Not specified by official sources. ¹

Useful resources

• Official NAICS 2022 page for NAICS 238220. ¹
• SBA Size Standards lookup for NAICS 238220. ¹⁰
• SAM.gov Wage Determinations for construction and alteration work. ¹¹
• Federal PSC Manual to align equipment/service PSCs (e.g., PSC J041, PSC J045). ⁹
• GSA MAS SIN 561210FAC (Facilities Maintenance and Repair). ¹²
• DOE FEMP covered product categories and efficiency requirements. ¹³
• EPA Section 608 Refrigerant Management Program. ¹⁴
• EPA WaterSense specifications and product registry. ¹⁵
• GSA P100 Facilities Standards for mechanical/plumbing. ¹⁶
• FAR Part 36 (Construction) policy and procedures. ¹⁷
• OSHA 29 CFR 1926 construction safety standards. ¹⁸
• ENERGY STAR HVAC and water-heating specifications. ¹⁹

References

1. https://www.census.gov/naics/?input=238220&year=2022&details=238220
2. https://www.census.gov/naics/?input=238210&year=2022&details=238210
3. https://www.census.gov/naics/?input=237110&year=2022&details=237110
4. https://www.census.gov/naics/?input=333415&year=2022&details=333415
5. https://www.census.gov/naics/?input=423730&year=2022&details=423730
6. https://www.census.gov/naics/?input=221330&year=2022&details=221330
7. https://www.census.gov/naics/?input=541330&year=2022&details=541330
8. https://www.census.gov/naics/?input=561210&year=2022&details=561210
9. https://www.acquisition.gov/sites/default/files/manual/PSC_Manual.pdf
10. https://www.sba.gov/size-standards
11. https://sam.gov/content/wage-determinations
12. https://www.gsaelibrary.gsa.gov/ElibMain/sinDetails.do?executeQuery=YES&scheduleNumber=MAS&specialItemNumber=561210FAC
13. https://www.energy.gov/femp/covered-product-categories
14. https://www.epa.gov/section608
15. https://www.epa.gov/watersense
16. https://www.gsa.gov/real-estate/design-construction/engineering-and-architecture/facilities-standards-p100
17. https://www.acquisition.gov/far/part-36
18. https://www.osha.gov/laws-regs/regulations/standardnumber/1926
19. https://www.energystar.gov/products/heating_cooling