The American Institute of Architects (AIA) Economics & Market Research Group’s Architecture Billings Index (ABI) decreased 3.9 points to 43.3 in September, while design contracts dipped 0.9 points from August to 46.3. Billings were below 50 in all sectors and regions. Backlogs declined to 6.1 months, down from 6.5 months at the start of 2025. An ABI score above 50 indicates growth. See AIA
