The Architecture Billings Index (ABI) in March was 51.9, up from a mark of 50.3 in the previous month, according to the American Institute of Architects (AIA).

This reflects an increase in design services, as any score above 50 indicates an increase in billings. The new projects inquiry index was 58.1, down from a reading of 59.5 the previous month.

The ABI reflects the approximate nine- to 12-month lead time between architecture billings and construction spending.

“The first quarter was somewhat disappointing in terms of the growth of design activity, but fortunately expanded a bit entering the traditionally busy spring season,” says AIA chief economist Dr. Kermit Baker. “The Midwest is lagging behind the other regions, but otherwise business conditions are generally healthy across the country. As the institutional market has cooled somewhat after a surge in design activity a year ago, the multi-family sector is reaccelerating at a healthy pace.”

Regionally, the South recorded the highest ABI (52.4), followed by the Northeast (51.0), West (50.4) and Midwest (49.8).

The index by sector was as follows: multi-family residential (55.7), commercial industrial (51.8), mixed practice (50.0) and institutional (48.0).