The number of sub-applications depends on the scope of construction and the local building department's requirements.
For a typical new residential construction project, the most common sub-permits include electrical, plumbing, mechanical (HVAC), and roofing. Additional permits may be required for pools, fences, driveways, windows and doors, fire protection systems, or other specialized work.
Each municipality has its own requirements, so the exact number is determined by the approved plans and permit conditions.