Design services at architecture firms continue to prove the health of the construction market, as the Architecture Billings Index (ABI) recorded its fourth straight month of growth.

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 (AIA) reported the May ABI score was 53.0, up from a mark of 50.9 in the previous month. This reflects an increase in design services, as any score above 50 indicates an increase in billings. The new projects inquiry index was 62.4, up from a reading of 60.2 the previous month, while the new design contracts index increased from 53.2 to 54.8.

“The fact that the data surrounding both new project inquiries and design contracts have remained positive every month this year, while reaching their highest scores for the year, is a good indication that both the architecture and construction sectors will remain healthy for the foreseeable future,” says AIA chief economist Dr. Kermit Baker. “This growth hasn’t been an overnight escalation, but rather a steady, stable increase.”

Regional ABI averages are: South (56.1), West (52.3), Midwest (50.4) and Northeast (46.5).

Sector index breakdown is: mixed practice (55.8), multi-family residential (51.3), commercial / industrial (51.2) and institutional (51.2).