AIA Billings Declined 2.5 Points to 44.7 in September

Washington, DC, October 21, 2026—The American Institute of Architects/Deltek Architecture Billings Index (ABI) September score fell to 44.7, down from August’s score of 47.2, marking the largest share of firms reporting declining billings since May. 

While inquiries for new projects increased modestly to 53.2 in September, the value of newly signed design contracts dropped to 43.7.

Billings remained weakest in the Northeast and continued to soften in the South, while firms in the Midwest and West reported stable conditions. Commercial and industrial firms posted modest growth for a second consecutive month, but billings declined again at institutional and multifamily residential firms, with the latter continuing to see significant weakening from earlier this year.

Despite softer demand, firms maintained a relatively healthy pipeline of future work. Average project backlogs stood at 6.2 months at the end of the third quarter, down from 6.6 months at the end of the first quarter. Backlogs remained stable at 8.1 months among large firms with annual billings of $5 million or more and at 8.0 months for firms specializing in institutional projects. Meanwhile, small firms with annual billings under $250,000 saw backlogs increase from 3.1 months to 3.8 months.  Multifamily residential firms experienced the sharpest decline in backlogs, falling from 6.2 months in March to 4.8 months in September.

“This is an increasingly difficult environment for architecture firms,” said AIA chief economist Richard Branch. “Weakening billings are being compounded by a soft economy, challenging project financing and growing caution among clients. With fewer projects moving forward, there is little reason to expect a meaningful improvement in business conditions in the near term.”

Regional averages were as follows: West (50.7); Midwest (50.6); South (43.1); Northeast (39.1).

The sector index breakdown was commercial/industrial (50.9); institutional (47.6); multifamily residential (42.9); mixed practice (firms that do not have at least half of their billings in any one other category) (41.5).

The project inquiries index score was 53.2, and the design contracts index score was 43.7.

The regional and sector categories are calculated as three-month moving averages and may not always average out to the national score.