Architectural Billings Index: May’s 2025 national Architectural Billings Index of 47.2 was down from April’s 43.2, which is below the expansionary zone, (>50). U.S. architecture firms specializing in Institutional and Residential all reported a decrease in design activity in May.

The design contracts sub-index was up at 45.9. Regional monthly scores were – South: 49.2, West: 44.3, Midwest: 43.5 and Northeast 43.6.

The Architectural Billings Index (ABI) is a leading economic indicator that provides an approximately nine to 12-month glimpse into the future of nonresidential construction spending activity. The results are seasonally adjusted to allow for comparison to prior months. Scores above 50 indicate an aggregate increase in billings, and scores below 50 indicate a decline.

Figure 1 lists the overall ABI and its sub-indexes. It presents and compares monthly and 3MMA data, showing percentage point change on both a three and 12-month basis, as well as momentum. Green denotes positive change, while red indicates negative. National momentum, (3-month y/y minus 12-month y/y) was up 0.6% while design contract momentum decreased 2.2%. Regionally, South and Midwest, all posted a positive momentum, ranging from 3.9% in the South to 8.1% in the Midwest. Residential and Commercial / Industrial facilities also posted a 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.