Do I need a permit for basement finishing in Unincorporated Harrison County?

Most likely yes. Basement finishing usually requires a permit in Kentucky. Confirm the specifics with Unincorporated Harrison County.

Kentucky does not require a building permit or inspection for a single-family dwelling unless the local government has passed an ordinance creating a residential inspection program (KRS 198B.060 and 815 KAR 7:125, Section 2(2)(a)), so the first question is whether the city or county covering the address has one. Where a basement contains sleeping rooms, each one needs an emergency escape and rescue opening with a sill no more than 44 inches above the floor, and an opening below grade needs a window well (KRC Section R310.1). Basement walls that are part of the building thermal envelope must be insulated from the top of the wall down to the design frost depth (KRC Section N1101.2.1); the energy provisions follow the 2009 International Energy Conservation Code. New wiring needs a state-required electrical permit, and a new bathroom needs a plumbing permit, whether or not a local building program exists (KRS 227.480, 815 KAR 20:050). This basement project adds a bedroom, a bathroom or wet bar, or new electrical circuits, or moves the furnace or water heater. Finishing work of this kind normally needs a building permit and the matching trade permits. A basement bedroom needs an emergency escape and rescue opening, such as an egress window or door, which is one of the most common reasons basement work fails inspection. Plan for framing, electrical and plumbing rough-in inspections before insulation and drywall go up.