AIA's monthly Architecture Billings Index (ABI) for May came in at a score of 50.2. This is a 0.3-point decrease from last month's score of 50.5, leaving the index little change since last month. The ABI is a leading economic indicator of construction activity in the U.S. and reflects a nine- to 12-month lead time between architecture billings and construction spending nationally, regionally, and by project type. A score above 50 represents an increase in billings from the previous month, while a score below 50 represents a contraction.

"The last four consecutive months, firm billings have either decreased or been flat, the longest period of that level of sustained softness since 2012,” said AIA chief economist Kermit Baker, Hon. AIA, in a press release. “While both inquiries into new projects and the value of new design contracts remained positive, they both softened in May, another sign the amount of pending work in the pipeline at firms may be starting to stabilize.”

In May, design contracts posted a score of 50.9, a 1.2-point decrease from April's score of 52.1.

The scores for regional billings—which, unlike the national score, are calculated as three-month moving averages—increased in three of the four regions in May, with only one region posting a score below the threshold of 50. The billings score for that region, the Northeast, did rise 2.4 points to a score of 47.5. Meanwhile, design services increased by 1 point to a score of 50 in the West and by 2.3 points to a score of 51.6 in the Midwest. Billings eased slightly in the South decreasing by 0.2 points to a score of 51.4.

Also last month, the billings scores fell in two of the four individual industry sectors. The institutional sector's score decreased 1.2 points to a score of 48, and the multifamily residential score decreased by 1.4 points to a score of 46. The commercial/industrial sector score rose by 6.4 points to a score of 53, while the mixed practice sector increased by 2.2 points to a score of 55.4. (Like the regional billings, sector billings scores are also calculated as three-month moving averages.)