The recent readings
The AIA/Deltek Architecture Billings Index scored 46.6 for July 2026, published August 19, indicating a further softening from June. Any reading below 50 means more responding firms reported declining billings than rising ones.
June, published July 22, came in at 47.3 — an improvement of roughly three points from May but still in contraction. May, published June 24, was 44.5, the weakest reading since January 2026, and the month in which the project inquiries index fell below 50 for the first time in four months.
AIA characterized the June reading as marking 41 months without a majority of firms reporting billings growth, and the July reading as extending the downturn to nearly three and a half years.
Where the weakness sits
The June detail, reported as three-month moving averages, shows the softness spread across every region and sector while varying in degree. By region: South 49.5, West 45.6, Midwest 45.1, Northeast 44.9. By sector: institutional 47.4, commercial and industrial 46.7, multifamily residential 45.6, and mixed practice 42.7.
Multifamily residential at 45.6 is the figure most relevant to housing supply. Architectural design work precedes construction by a year or more, so a sustained contraction in multifamily billings points to a thin apartment pipeline well beyond the current delivery slowdown.
Two forward indicators diverged in June. The project inquiries index stood at 56.1, comfortably in expansion, while the design contracts index was 49.8 — essentially flat. Firms were being asked about work at a healthy rate; that interest was not converting into signed contracts.
Backlogs are thinning
Average backlog at responding firms fell to 6.3 months in the second quarter of 2026 from 6.6 months in the first. Backlog is the cushion that lets a firm survive a period of weak new work, and it has been eroding rather than rebuilding.
Analysis: a three-tenths decline in a single quarter, in an index already contracting for years, describes a profession working through committed projects faster than it replaces them. The employment data point the same way — AIA noted architecture-services employment fell in June for a fourth consecutive month, with roughly 900 jobs lost since January 2026.
That combination matters for the construction cycle. Design capacity that leaves the industry does not return quickly, which can constrain how fast building recovers when financing conditions eventually improve.
What the index can and cannot tell you
The ABI is a diffusion index built from a monthly survey of AIA member firms. Fifty means no change; the distance from fifty indicates how widely shared the direction is, not how large the change is in dollar terms.
AIA estimates the index leads nonresidential construction spending by roughly nine to twelve months. That makes it a forecasting input rather than a description of current activity, and it should not be read alongside coincident measures as though it described the same period.
Regional and sector sub-indexes are three-month moving averages and do not average to the national figure. Their value lies in the ranking between them, which in mid-2026 placed multifamily residential design near the bottom of the list.