Although spending on private non-residential real estate projects jumped 17% in the past year, architects and builders are keeping an eye out for signs that the worldwide credit crunch may be spreading through the entire real estate market, according to Building Design + Construction.

The commercial real estate market has helped keep the economy afloat as the housing market has plummeted. But even before the housing slowdown, commercial lenders were  tightening standards and reporting that more developers were falling behind on loan payments.

U.S. banks and thrifts reported a 40% rise in past-due construction and development loans in the second quarter of 2007, according to the Federal Deposit Insurance Corp. Some contractors are reporting that lenders have reworked pricing and risk-analysis models.

Still, confidence remains high among architecture firms, which often are the first to lose work in a development slowdown. The American Institute of Architects’s July forecast high hit the second-highest level since the group starting keeping records in 1995.