The Architecture Billings Index, a measurement of demand for design services, softened in January after a strong 2014.

And while economists say the slowdown may be due to harsh winter weather, it is also concerning for the construction industry. The ABI indicates the level of new construction that can be expected in the next 9 to 12 months.

"The easing in demand for design services is a bit of a surprise given the overall strength of the market over the past nine months," said Kermit Baker, chief economist for the American Institute of Architects, in a prepared statement.

The national ABI score for January was 49.9, down from December's 52.7. The index uses 50 to represent flat activity while anything about that is seen as an increase in demand for design servces.

Regionally, the Midwest fared a bit better with a score of 50.8. The South still had a strong month with 54.8 while the West and Northeast both dropped to 49.3 and 46.0, respectively. ABI's regional data is based on a three-month average ending in January.

"Likely some of this can be attributed to severe weather conditions in January," Baker continued. "We will have a better sense if there is a reason for more serious concern over the next couple of months."