I live in New York and happen to be an Architect and in New York you are required to have a heat detector (Rate of Rise detector) in your garage. In fact the code requires a smoke detector in each bedroom and one in the hall outside of a bedroom and at least one on each floor, also a heat detector is required in the mechanical room.

Also if it is new construction you should have a fire separation between any Garage and living space. Typically a layer of 5/8" type "X" gypsum wall board on the garage side and 1/2" gypsum wall board on the living space side will be sufficient to make a fire separation.

Of course you should check with the local building inspectors. This is for new construction only, older houses may not be up to present codes and don't have to be unless they are renovated.