Every New York neighborhood has a few towers mushed up against little old buildings. That’s how our zoning works: The big developer buys the air over the little guy, ensuring that another tower won’t rise there. But Townhouse Management, developer of the Aurora on Third Avenue near 37th Street, has gone even further. The Aurora doesn’t just hug its neighbor – it extends several feet over it. “It took some engineering,” says developer Mitchel Maidman, “and was a little more expensive.” Oddly, the folks below aren’t griping, much. Says Steven Kaiden, who owns and lives in the smaller building, “We knew they were doing this, so we were compensated.” But another neighbor is less than pleased: “We’re being locked in.”