The AIA's monthly Architecture Billings Index (ABI) came in at a score of 52.0 in April, marking the seventh consecutive month of gains. 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, as seen this month, represents an increase in billings from the previous month, while a score below 50 represents a contraction.

April's score marks a one-point increase over March's reading of 51.0, indicating that business continues to trend upward despite labor shoratages and cost inflation of building materials. Like last month, new project inquiries—which AIA economists consider to be the most reliable indicator of future billings—decreased to a score of 56.7, indicating that demand for design services could be softer again in May.

“While there was slower growth in April for new project work coming into architecture firms, business conditions have remained healthy for the first four months of the year,” said AIA chief economist Kermit Baker, Hon. AIA. “Although growth in regional design activity was concentrated at firms in the sunbelt, there was balanced growth so far this year across all major construction sectors.”

In April, design contracts received a score of 50.1—a 1.4-point decrease from March's significant score drop to 51.5. Design contracts continue to measure above the 50-point threshold—as they have every month in the last year—a sign that momentum is strong, despite small month-to-month fluctuations.

The scores for regional billings—which, unlike the national score, are calculated as a three-month moving average—increased in two of four regions during March. The West (55.1) saw an increase of 1.7 points while the Northeast reported a score of 50.3, bringing the region back to a score above 50 for the first time since November. The South (51.8) saw a 1.4-point decrease, while the Midwest (49.6) fell 1.1 points to a score below 50.

Billings decreased in three of four sectors in March, but all sectors posted a score above 50, indicating growth. With a 2.3-point increase, the institutional sector (52.0) was the only sector to see a higher rate of business activity in May after a suffering a contraction in April. Billings in the commercial/industrial sector (52.7) and the the mixed-use sector (50.6) fell slightly by .4- and .5-points, respectively. April is the first time six months that demand for design services the multifamily residential sector is not the strongest after falling 2.7 points to a score of 50.7. (Results of sectors are also calculated as a three-month moving average.)