ABC Construction Backlog Climbs to 8.7 Months in September

By Marcus Bennett

ABC's Construction Backlog Indicator rose to 8.7 months in September, up 0.2 months from August and from September 2025, the trade group reported from Washington on October 14.

The reading, drawn from an ABC member survey conducted September 21 through October 5, marks the second consecutive monthly increase. Backlog now sits at its highest level since mid-2025.

Why is data center share widening?

Commercial and institutional backlog, which softened through mid-2026, climbed in September to its highest monthly level since July 2025. Heavy industrial backlog moved the opposite direction, falling to its lowest reading since March. The category retains a 0.5-month gain over the prior twelve months.

ABC Chief Economist Anirban Basu pointed to one segment. "Backlog increased for the second straight month in September as data center work continues to keep contractors busy," he said.

Fifteen percent of ABC members hold data center contracts. Those firms averaged 11.3 months of backlog in September, three months more than contractors without such work. Scale dictates access to that pipeline:

• 39% of contractors with annual revenue above $100 million carry data center assignments today.
• Among contractors with revenue below $100 million, the share is one in ten.

What does the confidence split signal?

ABC's Construction Confidence Index added context. The September components:

• Staffing expectations: rose.
• Sales expectations: fell.
• Profit margin expectations: fell.

All three readings remained above 50, the dividing line between expansion and contraction over the next six months.

For practitioners, the split carries two signals. Contractors still plan to hire, suggesting they expect work to land. Sales and profit margin expectations declined together, pointing to softer pipelines and continued cost pressure on bid work. Cost escalation on data center projects has been a recurring concern among ABC members throughout 2026.

What changes for Q4 bidding?

A 0.2-month increase does not, on its own, redraw the contracting environment. The composition does. Work is concentrating in firms with data center exposure and, within that group, in firms already operating at the largest scale. Mid-tier and smaller contractors face a backlog ceiling roughly three months below the data center subset, equivalent to one fewer quarter of committed work.

The heavy industrial retreat adds a second marker. Process manufacturing, refining, and utility-scale energy projects anchor that category. A sustained decline would indicate that capital spending tied to reshoring and decarbonization has cooled, even as compute infrastructure accelerates. ABC will publish October's backlog reading in mid-November. A third consecutive monthly gain would push the headline toward 9.0 months for the first time since early 2025 and lock in data center demand as the cycle's principal driver.