After three months of accelerating demand for design services, the Architecture Billings Index reflected a somewhat slower pace of growth in October. As a leading economic indicator of construction activity, the ABI reflects the approximate nine- to 12-month lead time between architecture billings and construction spending.

The American Institute of Architects reported the October ABI score was 51.6, down from a mark of 54.3 in September. This score reflects an increase in design services (any score above 50 indicates an increase in billings). The new projects inquiry index was 61.5, up from the reading of 58.6 the previous month.

“There continues to be a lot of uncertainty surrounding the overall U.S. economic outlook and therefore in the demand for nonresidential facilities, which often translates into slower progress on new building projects,” said AIA Chief Economist Kermit Baker. “That is particularly true when you factor in the federal government shutdown that delayed many projects that were in the planning or design phases.”

Key October ABI highlights:

• Regional averages: West (55.9), South (54.4), Midwest (51.6), Northeast (49.7)

• Sector index breakdown: multifamily residential (57.0, commercial / industrial (53.7), mixed practice (53.2), institutional (50.2).