Comfort Systems Added $8.4 Billion of Backlog in Twelve Months

Comfort Systems USA reported third-quarter results on Oct. 22 that put its backlog at $17.81 billion as of Sept. 30, against $9.38 billion at the same point a year earlier. A single mechanical and electrical contractor added roughly $8.4 billion in booked work over twelve months.

Revenue for the quarter was $3.77 billion, up from $2.45 billion. Nine-month revenue reached $9.90 billion against $6.46 billion, and diluted earnings were $13.91 a share compared with $8.25. Backlog rose $3.8 billion from the $14.06 billion reported at June 30. Same-store backlog, which strips out acquired companies, stood at $17.39 billion, so almost all of the increase came from work won rather than firms bought. Operating cash flow for the quarter was $1.01 billion, against $553.3 million a year earlier. Chief Executive Brian Lane credited the quarter to relentless demand. The company now lists 211 locations in 155 cities, up from 197 locations in 143 cities in its May investor presentation.

That presentation is where the demand gets specific. Comfort Systems put technology, which it defines as data centers and chip manufacturing, at 56 percent of year-to-date revenue, with manufacturing at another 19 percent. Healthcare, government, education, retail, office buildings and other work split the remaining 25 percent. Electrical accounted for 28 percent of revenue and 27 percent of gross profit across roughly 50 operating companies; mechanical carried the rest. Technology by itself was a larger share of revenue than every non-industrial market the company tracks combined.

The project mix matters as much as the sector mix. New construction was 57 percent of revenue and modular work another 17 percent, which means a growing share of electrical hours is logged in prefabrication shops rather than in the field, on assemblies built indoors and then shipped and set. Existing construction added 15 percent. Service and maintenance together came to 11 percent, so this is overwhelmingly new construction with a defined completion date rather than recurring building upkeep. Work of that shape ramps crews hard and releases them when a campus energizes.

The hiring arithmetic is the constraint. Comfort Systems counted more than 23,000 employees in May, when backlog stood at $12.46 billion; backlog has since climbed another $5.35 billion. The national pipeline does not move at that speed. The Bureau of Labor Statistics counted about 821,000 electricians in 2025 at a median wage of $63,190, and projects employment to reach 896,900 by 2035, a 9 percent increase, with about 72,700 openings a year once retirements and exits are counted. Electrical contractors and other wiring installation contractors employ 66 percent of them at a median of $61,570. Most electricians still learn the trade in a four- or five-year apprenticeship that logs roughly 2,000 hours of paid on-the-job training a year, and most states license the result.

Backlog can double in twelve months. A journey-level electrician takes four to five years.