Fewer architectural firms reported a decline in billings in December than in November, reports the American Institute of Architects (AIA). The institute recently released its monthly Architecture Billings Index (ABI), offering an insight into the number of design contracts in December. The data show that in the final month of 2025, billings increased to 48.5 from November’s reading of 45.3; however, a score below 50 indicates a decline in billings.

AIA officials report that while fewer firms reported decreases in December, declining design contract values suggest a near-term rebound is unlikely. Despite this, firm backlogs remain strong, averaging 6.3 months. Large firms with annual billings of $5 million or more report backlogs of 8.6 months, while institutional specialists average 8.2 months.

“Despite the ongoing decline in billings at most architecture firms, there are a few signs of potential improvement on the horizon,” says AIA chief economist Kermit Baker. “The number of inquiries into future project work continues to grow, and Midwest firms saw billings increase for the fourth consecutive month in December. In general, however, overall conditions remain weak across all specializations. Multifamily residential firms faced the steepest declines, while institutional firms experienced a slightly slower pace of decline compared to earlier in the year.”

Institutional (48.7); commercial/industrial (47.8); multifamily residential (45.5); mixed practice (44.0).

52.9

47.5