Demand for design services in the construction industry had been on a modest rise the first two months of the year, but it took a notable dip in March.

The Architectural Billings Index (ABI), a leading economic indicator of construction activity, yielded a March score of 48.8, nearly two full points below its 50.7 mark in February, according to the American Institute of Architects (AIA). The ABI reflects the approximate nine- to 12-month lead time between architecture billings and construction spending, and any score above 50 reflects an increase in billing.

“This protracted softening in demand for design services is a bit of a surprise given the overall strength of the market the last year and a half,” says AIA chief economist Kermit Baker. “Hopefully, some of this can be attributed to severe weather conditions over this past winter. We will have a better sense if there is a reason for more serious concern over the next couple of months.”

The south region tallied the highest ABI average at 52.8, with the Midwest getting the lowest score at 46.6. The multi-family residential category was the highest-rated sector (52.1), while the mixed practice category recorded a 47.6 score, the lowest of the four sectors considered.