Amid a continued high level of inquiries for possible new projects, the Architecture Billings Index (ABI), which presages activity in the nonresidential construction sector, last month reached its highest mark since August 2008, the American Institute of Architects (AIA) said.

The October ABI rating was put at 46.1, up 7 percent from 43.1 the previous month but still indicating a continued decline in demand for design services, while the "new projects inquiry"...