Contracts for future construction in San Diego County dropped 9 percent for the first seven months of 2012 compared with the same period a year ago, according to data from McGraw-Hill Construction.

The county had just over $2.08 billion in total contracts — including residential and nonresidential projects — in the January-July span, down from $2.3 billion in the first seven months of 2011.

Local residential construction contracts are essentially on par with 2011 so far this year, at $673.6 million, while nonresidential contracts are down 13 percent, at $1.4 billion.

McGraw-Hill’s research and analytics unit defines residential as one and two-family houses and apartments. The nonresidential category includes commercial, educational, religious, government and other non-home projects.

The month of July saw San Diego County’s nonresidential contracts rise 36 percent from July 2011, to $155.1 million, while residential contracts dropped 45 percent, to $62 million. The overall year-over-year change for July was a 4 percent decline.

Researchers said the state of California also experienced a 9 percent drop from a year ago in total construction contracts in the January-July period, to $24.2 billion.