May marked the fourth straight month the Architecture Billings Index was above 50; this time at 53.0, a rise of 2.1 points from April. Reports from mixed-practice firms resulted in a score of 55.8, making it the strongest component. Multifamily and nonresidential readings slipped a little but still remained north of 50.

Additionally, the inquiries index rose to a healthy 62.4, design contracts advanced to 54.8, and the ABI's three-month moving average basis increased to 52.7 in May. According to the American Institute of Architects and Wells Fargo Securities, "the overall trend points to moderate gains in total nominal private construction spending in the coming year."

Regionally, the South's ABI increased to 56.1 in May from 55.3 in April, activity remained unchanged in the West at 52.3, and fell slightly in the Midwest but still ended up in positive territory unlike the Northeast, which fell below 50.

The ABI gauges the number of firms that report an increase in design services compared to the previous month, on the order of five percent or more.