The national Architectural Billings Index rose to 47.6 in October 2025, up from 43.3 in September. Billings at U.S. architecture firms continue to decline but at a slower pace. Any reading below 50 indicates contraction.  Sector trends were mixed. Multifamily residential and institutional firms reported relatively stronger activity compared to other categories, though still below the expansion threshold. Commercial and industrial firms remained under 50, reflecting ongoing caution in those markets.

• The design contracts index measured 47.1.
• The project inquiries index climbed to 54.8, the highest reading in roughly 18 months.

Regionally, the Midwest reported 49.6 and continued to show the most stable conditions.

1. The South measured 45.3.
2. The Northeast measured 45.1.
3. The West recorded 42.1 and remained the slowest region in the country.

The Architectural Billings Index provides a nine to 12 month outlook for nonresidential construction spending and is seasonally adjusted for consistent comparison. Scores above 50 indicate growth in design billings. Scores below 50 reflect a decrease.

Figure 1 lists the overall ABI and its sub-indexes and compares monthly and three month moving average results, including percentage point changes over three and twelve months and overall momentum. Green indicates positive movement and red indicates negative.

1. National momentum measured down 1.4 percent.
2. Design contract momentum increased 4.7 percent.

• Regionally, only the Midwest posted positive momentum at 6.4 percent.
  • The Northeast, South, and West each posted negative momentum ranging from 3 to 9 percent.
• Residential and Commercial/Industrial categories recorded positive momentum Institutional posted negative momentum.

At Gerdau, we follow the ABI because it is a leading indicator of non-residential construction activity with an approximate nine to 12-month lead time to groundbreaking. The ABI has a proven track record and, as such, it is useful for business planning purposes.