San Diego County’s contracts for future construction rose 59 percent in the first four months of 2012 compared with the same period a year ago, according to data reported May 23 by New York-based McGraw Hill Construction.

Residential and nonresidential contracts totaled more than $1.2 billion from January to April, compared with $779.6 million in the first four months of 2011.

Nonresidential activity has surpassed $920.4 million this year, more than doubling the year-ago figure. The $325.5 million in residential contracts is slightly higher than the $322 million for January-April of 2011.

The nonresidential side was boosted this year largely by April’s $656.3 million in contracts, accounting for 71 percent of contracts in that category so far in 2012. In April 2011, the nonresidential total was $55.1 million.