Commercial construction contractors are ending 2025 with steady backlogs and guarded optimism, even as the ongoing federal government shutdown—now stretching into its third week—has halted the release of key economic data from the Bureau of Labor Statistics and Census Bureau. 

The suspension of reports on employment, inflation and construction spending has left businesses and policymakers flying partly blind, prompting private firms to fill the gap with their own indicators.

Backlogs Remain Healthy Despite Shifts

ABC's Construction Backlog Indicator for commercial work remained unchanged at 8.5 months in September—down slightly from 8.6 months in September 2024. This stability masks significant variation across sectors: backlog has declined in commercial, institutional, and heavy industrial categories but increased substantially in infrastructure work.

"Falling industrywide employment, a dearth of job openings and ongoing decreases in construction spending have not diminished ABC contractor member backlog or confidence," said ABC Chief Economist Anirban Basu. 

He attributed this resilience to strong public sector activity supporting infrastructure projects and robust data center construction, which is providing significantly higher backlogs for contractors involved in those projects (12.0 months versus 8.0 months for those without data center work).

ABC's Construction Confidence Index readings for profit margins and staffing both increased in September, with all three confidence components remaining above 50, indicating expectations for growth over the next six months.

FMI Corporation's third-quarter outlook is considerably more cautious, forecasting just 1% growth in overall U.S. construction spending for 2025—a dramatic slowdown from 2024's 7% growth. While sectors like data centers, transportation and power infrastructure remain strong, other commercial segments face challenges.

The divergence in outlook is stark. The Dodge Momentum Index, which tracks projects entering planning and typically predicts construction activity 12-18 months ahead, rose 3.4% in September to 304.6 and is up 33% year-to-date.

"Planning momentum remained steadfast for data centers, healthcare, and public buildings throughout September and will correlate to stronger construction spending in early 2027," said Sarah Martin, associate director of forecasting at Dodge Construction Network.

Yet FMI's Civil Infrastructure Construction Index showed about 52% of firms reporting higher project backlogs than the same quarter last year, even as the firm's Nonresidential Construction Index plummeted from 56.9 to 43.5 in Q2 2025—its lowest reading since 2020—with industry leaders citing rising costs, declining backlogs and growing uncertainty.

The AIA's Architecture Billings Index—a leading indicator that typically predicts construction activity 9-12 months ahead—has shown persistent weakness in 2025. After briefly stabilizing at 50.3 in October 2024, the index declined to 45.6 in January 2025 and remained below 50 through mid-year, signaling continued softness in design billings that could portend reduced nonresidential construction activity in 2026.

QUICK READ: 3 Takeaways

• Contractor Backlogs Remain Steady: ABC’s Construction Backlog Indicator held at 8.5 months in September 2025, nearly unchanged from a year earlier, signaling overall stability even as the federal shutdown halts the release of key government data.
• Infrastructure and Data Centers Offset Softness in Other Sectors: While backlog has declined in commercial, institutional, and heavy industrial categories, it rose sharply in infrastructure work. Contractors tied to data center projects reported backlogs averaging 12 months, compared to 8 months for others.
• Confidence Levels Point to Modest Growth Ahead: ABC’s Construction Confidence Index readings for profit margins and staffing increased in September, with all three components remaining above 50—indicating expectations for continued expansion through early 2026.

The common thread across nearly all private data sources is the outsized role of data center construction in driving commercial activity. These projects, fueled by artificial intelligence infrastructure demands, are creating significant work for contractors—but also raising questions about sustainability as this sector inevitably moderates.

"After a prolonged period of uncertainty, owners and developers are advancing projects into planning, but activity is expected to normalize in future months," Martin said, suggesting the data center boom may be reaching maturity.