Does a detached garage require a fire alarm if a bedroom or guest room is attached to the garage. Or, will the bedroom or guest room attached to the garage required the fire alarm?
Edit to add: If residential and no fire alarm is installed a single station smoke alarm would need to be installed. If commercial and garage is so equipped with fire alarm (as long as it is not a sprinkler monitoring system) then the alarm should (depending on AHJ and any allowances/variances) be brought in to the unit and the smoke detector installed in accordance with NFPA 72.