The Dodge Momentum Index fell 7 percent in March to 117.4 from its revised February reading of 126.4, according to Dodge Data & Analytics. The March decline follows three months of gains.

The index is a monthly measure of the first (or initial) report for nonresidential building projects in planning, which have been shown to lead construction spending for nonresidential buildings by a full year.

The index has been volatile over the last year, increasing in seven months and dropping in five. The March decline was due primarily to a 15-percent drop by institutional planning, while commercial planning fell less than one percent.

Despite its retreat, institutional planning activity is 7 percent above its level in March 2015, while commercial planning is down 4 percent from last year. The overall index is essentially even with its year-ago level.

In March, seven projects entered planning with a value that exceeded $100 million.