Do I need a permit for basement finishing in Evansville?

Most likely yes. Basement finishing usually requires a permit in Indiana. Confirm the specifics with Evansville.

Indiana's Section R314.3 requires smoke alarms in each room designed for sleeping, on each level, and on the basement ceiling near the stairway. Under Indiana's R314.2.2 and R315.2.2, alterations or additions requiring a permit trigger smoke and carbon monoxide alarms as for new dwellings, except electrical work in existing rooms other than new or relocated bedrooms. Section R310.1 of the 2020 Indiana Residential Code (emergency escape and rescue opening required) applies to basement bedrooms, and Indiana deleted its Exception 2, so ask the local office which escape window or door your layout needs. Indiana's N1107.1 makes Sections N1107 through N1111 of the energy chapter control the alteration, addition, and change of occupancy of existing buildings, so newly conditioned space must meet the energy provisions that apply to that work. 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.