The Architectural Billings Index (ABI) improved slightly in December, adding 0.1 points for a score of 55.4, extending its gains to three months after a sharp drop earlier in the year. The American Institute of Architects (AIA) notes that December marked the 34th month in a row that the ABI has boasted a score above 50 points—its best performance since its last long-term positive run between April 1998 and December 2000. Any score above 50 indicates growth; the AIA compiles the number based on surveys sent to 300 architecture firms that mainly work in the commercial sector.

Another healthy sign in December was that the index of new business inquiries gained 1.5 points for a score of 58.1, regaining some of the ground it had lost after falling nearly 10 points since July. Even so, the AIA’s chief economist, Kermit Baker, PhD, Hon. AIA, cautions that current economic uncertainty could translate into a slowdown for architectural billings and inquiries this year.

“As the country braces for a possible recession in 2008, there will likely be an easing in demand for design services,” Baker said in a statement accompanying the indices’ release. “While that is a natural reaction, it is important to note that with positive conditions for architecture billings going back over two years nonresidential construction is expected to one of the sources of strength in an otherwise uneven economy.”