Comfort Systems USA, Inc.

Comfort Systems USA, Inc. is a national provider of mechanical and electrical contracting services — the company that installs, maintains, and retrofits the heating, cooling, power, and plumbing systems in the commercial, industrial, and institutional buildings where Americans work, learn, heal, and process data, generating $9.10 billion in revenue in fiscal 2025. Through 50 operating units across 190 locations in 142 U.S. cities, Comfort Systems builds and services the invisible infrastructure that makes modern buildings habitable: HVAC systems, electrical distribution, piping, fire protection, and building automation controls.

This is a story about an old-economy contracting business that found itself at the intersection of the largest infrastructure build-out in a generation. The company's revenue has nearly doubled in two years — from $5.2 billion in FY2023 to a trailing-twelve-month run rate exceeding $11.2 billion — driven overwhelmingly by demand from technology companies building data centers and advanced manufacturing facilities. Gross margins that historically hovered near 19-20% have expanded past 24%, operating margins have nearly doubled, and the backlog stood at $14.06 billion as of June 2026, or roughly 1.3x trailing revenue. The market has noticed: shares traded near $1,831 in July 2026, giving the company an equity value of roughly $65 billion — about 45x trailing earnings.

The file turns on a single question: how much of the margin structure that Comfort Systems built during a supply-constrained super-cycle is durable enough to survive the eventual normalization of demand. No one questions whether the company is executing well today. The debate is about what "normal" looks like on the other side of the data center build-out, and whether the current multiple embeds an assumption that today's margins are permanent.