The institutional sector has helped lift the Architects Billings Index (ABI) to its highest mark since 2007, 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.

AIA reported the June ABI score was 55.7, up from 51.9 in May. This score reflects an increase in design services, as any score above 50 indicates an increase in billings. The new projects inquiry index was 63.4, up from 61.5 the previous month.

“The June numbers are likely showing some catch-up from slow growth earlier this year,” says AIA chief economist Dr. Kermit Baker. “This is the first month in 2015 that all regions are reporting positive business conditions and aside from the multi-family housing sector, all design project categories appear to be in good shape. The demand for new apartments and condominiums may have crested with index scores going down each month this year and reaching the lowest point since 2011.”

Regionally, the Midwest led ABI averages at 57.2, with the South at 54.9, West 50.7 and Northeast 50.4. Sector-wise, institutional led at 59.1, followed by mixed practice (54.7), commercial/industrial (51.6) and multi-family residential (47.0).