American architecture firms reported weaker billings in September, according to the latest AIA/Deltek Architecture Billings Index released today by Archinect. The index fell to 44.7 from 47.2 in August, and any reading below 50.0 indicates a decline from the previous month.
The report also said inquiries for new projects continued to rise modestly, reaching 53.2, while newly signed design contracts dropped to 43.7. That mix suggests clients are still exploring projects without converting as many of them into signed work.
By region, the Northeast remained the weakest market. Billings trends in the Midwest and West were stable, while commercial and industrial firms posted a second straight month of modest growth.
The report said firms ended the third quarter with an average backlog of 6.2 months, down from 6.6 months in the first quarter. Larger firms and institutional specialists were described as holding steadier.
Archinect published the report summary on October 21, 2026, based on the AIA/Deltek index.
Why it matters for AEC: The report points to softer near-term fee work and slower contract conversion, even with inquiries still coming in. The backlog figure suggests there is still work in hand, but the amount of committed design work has eased since the start of the year.
