We are adding some work bays onto a repair garage that is classified as Special Purposes Industrial. The existing garage has a sprinkler system installed during a rehab about 5 years ago, but I cannot find a reason why it was required to be installed throughout - there are some storage rooms for batteries and flammables, but those have a 2-hr separation from the main garage/office area. I could see why the storage might be sprinklered, but I am not clear why it was decided to add sprinklers to the whole building. The existing building is one-story, non-combustible construction and only about 4400sf. The addition will also be non-combustible and add about 1600sf. Do I need to extend the (unrequired) sprinkler system?