Detached Garage New. Detached Garage(1 story). - Detached Garage - 24x30ft detached garage metal building on concrete slab, 11ft tall walls- 24x30ft detached garage metal building on concrete slab, 11ft tall walls, will be added to the southern most corner of the back yard. - There will be electrical work inside to allow for lights, outlets, garage doors, etc. There will be no plumbing.