The AIA’s Architecture Billings Index ended the first quarter on the upswing, as the index moved up to a score of 51.9 in March from the February level of 50.3.

Increasapartment-406901_640ed demand in the multifamily residential sector helped fuel the overall index gain, the AIA said. Any index score above 50 represents an increase in billings.

The new projects inquiry index was 58.1, down from a reading of 59.5 the previous month. The design contracts index was 51.8.

“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,” said AIA Chief Economist Kermit Baker.

“The Midwest is lagging behind the other regions, but otherwise business conditions are generally healthy across the country,” Baker said. “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.”

The Architecture Billings Index serves as a leading economic indicator of construction activity, and reflects the approximate nine- to 12-month lead time between architecture billings and construction spending.

Key Index figures
Regional averages for the Architecture Billings Index were 52.4 for the South, 51.0 for the Northeast, 50.4 for the West, and 49.8 for the Midwest.

By sector, index numbers were 55.7 for multifamily residential, 51.8 for commercial/industrial, 50.0 for  mixed practice, and 48.0 for institutional.

The regional and sector categories are calculated as a three-month moving average; the national index, design contracts and inquiries indexes are monthly numbers.