Most lots here have more than one way in. There is the street side, and then there is the rear gate onto the trail, an alley or a shared side path. Our home alarm systems in Dunedin put contacts on every door and window, add motion detectors through the main living areas and use glass-break sensors on the single-pane and jalousie windows still common in older homes near downtown.
Outbuildings run on the same panel. A detached garage, workshop or carport where a golf cart sits overnight reports to the monitoring center exactly like your front door.