The Census Bureau's County Business Patterns for 2023 count 2,620 plumbing, heating and air-conditioning contractor locations with paid employees in Colorado. By county: Jefferson 316, Adams 268, El Paso 260, Arapahoe 251, Larimer 185, Denver 159, Weld 149, Douglas 122. Denver County has about half as many as Jefferson.
- Jefferson: 316 (198 with fewer than five employees)
- Adams: 268 (165)
- El Paso: 260 (150)
- Arapahoe: 251 (152)
- Larimer: 185 (106)
- Denver: 159 (98)
- Weld: 149 (93)
- Douglas: 122 (84)
The five Denver-area counties, Jefferson, Adams, Arapahoe, Denver and Douglas, hold 1,116 locations, 43 percent of the state. In every one of them, at least six in ten locations have fewer than five employees; in Douglas it is seven in ten.
The counts are locations with employees, by the county where the location sits, and a shop based in Jefferson works in Denver and Arapahoe too. Small counties are partly suppressed, which is why the county list sums to 2,603 against the state's 2,620. The shape is the useful part: the metro is dense with small shops, and a homeowner choosing between them is choosing between phones.
What ProxMedia does about it: an AI receptionist for HVAC companies and for plumbers, and the local search work that puts a Jefferson County shop in front of a Denver homeowner. The size-class note has the statewide split.
Source: US Census Bureau, County Business Patterns 2023, county file, Colorado, NAICS 238220 plumbing, heating and air-conditioning contractors (establishments with paid employees); counted on October 28, 2026.