From the latest press release from the American Institute of Architects:

Washington, D.C. – October 19, 2011 – Following the first positive score in four months, the Architecture Billings Index (ABI) reversed direction again in September.  As a leading economic indicator of construction activity, the ABI reflects the approximate nine- to twelve-month lag time between architecture billings and construction spending.  The American Institute of Architects (AIA) reported the September ABI score was 46.9, following a score of 51.4 in August.  This score reflects a sharp decrease in demand for design services (any score above 50 indicates an increase in billings).  The new projects inquiry index was 54.3, down from a reading of 56.9 the previous month.

“It appears that the positive conditions seen last month were more of an aberration,” said AIA Chief Economist, Kermit Baker, PhD, Hon. AIA. “The economy is weak enough at present that design activity is bouncing around more than usual; one strong month can be followed by a weak one.  The economy needs to be stronger to generate sustained growth in design activity.” 

Key September ABI highlights:

• Regional averages: Midwest (51.0), Northeast (50.8),  South (47.3), West (46.7)
• Sector index breakdown: commercial / industrial (52.4),  mixed practice (50.0), institutional (48.0), multi-family residential (46.4)
• Project inquiries index: 54.3

The regional and sector categories are calculated as a three-month moving average, whereas the index and inquiries are monthly numbers.

About the AIA Architecture Billings Index
The Architecture Billings Index (ABI), produced by the AIA Economics & Market Research Group, is a leading economic indicator that provides an approximately nine to twelve month glimpse into the future of nonresidential construction spending activity. The diffusion indexes contained in the full report are derived from a monthly “Work-on-the-Boards” survey that is sent to a panel of AIA member-owned firms. Participants are asked whether their billings increased, decreased, or stayed the same in the month that just ended as compared to the prior month, and the results are then compiled into the ABI.  These monthly results are also seasonally adjusted to allow for comparison to prior months. The monthly ABI index scores are centered around 50, with scores above 50 indicating an aggregate increase in billings, and scores below 50 indicating a decline. The regional and sector data are formulated using a three-month moving average. More information on the ABI and the analysis of its relationship to construction activity can be found in the White Paper Architecture Billings as a Leading Indicator of Construction: Analysis of the Relationship Between a Billings Index and Construction Spending on the AIA web site.

About The American Institute of Architects
For over 150 years, members of the American Institute of Architects have worked with each other and their communities to create more valuable, healthy, secure, and sustainable buildings and cityscapes.  Members adhere to a code of ethics and professional conduct to ensure the highest standards in professional practice.  Embracing their responsibility to serve society, AIA members engage civic and government leaders and the public in helping find needed solutions to pressing issues facing our communities, institutions, nation and world. Visit www.aia.org.