Architecture firm billings growth slowed in September but remained positive for the 12th consecutive month, the American Institute of Architects said in a release. The organization’s billings index score for September was 51.1, compared with 54.2 in August. Continued strength in new projects coming into architecture firms points to billings growth in the coming months. “The Midwest is continuing to see strong billings, leading the regional averages this month,” AIA Iowa Executive Director Jessica Reinert said in a statement. “The billings are reflecting the amount of work we have been seeing across the state and the forecast seems to be strong for firms for the rest of 2018.” The Midwest index was 59.7, while the South scored 54.1, the West 53.1 and the Northeast 46.6.