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AIA's ABI Falls Below 50 After Seven Straight "Up" Months

AIA-logoWashington, DC - After seven months of steady growth in the  demand for design services, the Architecture Billings Index (ABI) paused in September.  As a leading economic indicator of construction activity, the ABI reflects the approximate nine to twelve month lead time between architecture billings and construction spending. The American Institute of Architects (AIA) reported the September ABI score was 49.1, down from a score of 53.7 in the previous month. This score reflects a slight decrease in design services provided by U.S. architecture firms (any score above 50 indicates an increase in billings). The new projects inquiry index was 59.0, down from a reading of 62.5 the previous month, while the new design contracts index eased somewhat from 54.2 to 52.9.

“We’ve seen unexpectedly strong numbers in design activity for most of 2017, so the pause in September should be viewed in that context” said AIA Chief Economist, Kermit Baker, Hon. AIA, PhD. “Project inquiries and new design contracts remain healthy, and the continued strength in most sectors and regions indicates stability industry-wide.”

Key September ABI highlights:

• Regional averages: Northeast (56.9), South (54.0), Midwest (50.4), West (48.8)

• Sector index breakdown: commercial / industrial (54.0), mixed practice (52.2), multi-family residential (51.0), institutional (51.0)

• Project inquiries index: 59.0

• Design contracts index: 52.9

The regional and sector categories are calculated as a 3-month moving average, whereas the national index, design contracts 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 recently released White Paper, Designing the Construction Future: Reviewing the Performance and Extending the Applications of the AIA’s Architecture Billings Index 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. For more information, visit

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