The design industry endured its first double-dip in billings in well over a year to cap off 2013. According to the American Institute of Architects' (AIA) Architecture Billings Index (ABI), December saw demand for design services decline for the second month in a row, marking the first time contraction followed in consecutive months since May and June 2012.

From November to December 2013, the ABI score fell from 49.8 to 48.5, reflecting a decrease in demand for architecture services. (Any score above 50 means an increase in billings.) On the plus side, the index for new project inquiries rose from 57.8 in November to 59.2 in December and showed growth throughout 2013.

The December contraction ends an otherwise positive year, one that registered growth in billings in all but three months. Despite ending on a negative note, the overall strength in billings for the year mirrors the growth in jobs for architects throughout 2013.

National Highlights:
National billings: At 48.5, down from November's 49.8, the national billings score has come in under 50 for just three of the last 17 months.
Project inquiries: At 59.2, up from 57.8, this score fell under the high-water mark of 60 only five times in 2013.

Regional Highlights:
Northeast: At 42.8, down from 44.9, this is the third month of contraction for the region, following a 13-month positive streak that ended with October's index.
Midwest: At 47.0, down from November's score of 49.2, December marks the second month of contraction in a row.
South: At 51.2, down only slightly from 52.2, this is the 18th straight month of growth for this region.
West: At 53.2, up a bit from November's 51.0, this month marks the 17th straight month of growth for the region.

Sector Highlights:
Commercial/Industrial: At 47.1, down from 48.2, this is the second consecutive month of contraction for the sector.
Multi-family Residential: At 53.8, down from 54.0, this is nevertheless the 20th straight month for the sector above 50.
Institutional: At 44.8, down from 46.5, this month marks three consecutive months of decline.
Mixed Practice: At 51.0, December's score is down from November's 51.7, but still signals 16 straight months of growth for the sector.