The value of San Diego County’s construction starts rose 19 percent from the year-ago period in the first four months of 2017, topping $1.2 billion, although the region saw a decline in nonresidential project activity, according to the latest monthly numbers from Dodge Data & Analytics.

Based on the value of projects for which building permits were pulled during the January-to-April period, residential projects saw a 41 percent increase from a year ago, surpassing $757.9 million in value. But the nonresidential category was down 5 percent, to $462.8 million.

The residential category includes projects related to single-family and multifamily housing. The nonresidential segment covers office, industrial, retail, education, government and most other types of nonhousing construction.

For the month of April, overall building activity declined 15 percent from a year ago, to just over $240.1 million. The residential category rose 13 percent to $195.5 million, but growth in that segment was countered by a 60 percent drop in nonresidential project starts, to $44.6 million.