Can I Build ADU in Louisville, KY? (2026)

An Accessory Dwelling Unit (ADU) is a secondary housing unit on a residential lot — also called a granny flat, in-law suite, or backyard cottage. In Louisville, KY, ADUs are permitted by right under state law, making them one of the most accessible ways to add housing on your property. ADUs can be detached, attached to the main home, or created by converting an existing garage or accessory structure.

ADU Rules in Louisville

ADU Rules in Louisville: Detached ADU max size: 900 sq ft. Attached ADU max size: 45% of primary dwelling floor area. Setbacks: 5 ft side, 5 ft rear. Owner-occupancy: Louisville Metro does not impose owner-occupancy requirements for ADU approval. Both the primary unit and ADU may be independently rented..

Costs & Fees

ADU permits in Louisville: Total estimated permit cost: $2,000–$8,000 total fees. Contact the Louisville Metro Planning and Design Services for current fee schedule.

Timeline

Louisville Metro Planning and Design Services permit: typically 4-8 weeks for residential permits. Online permitting through Louisville Metro government portal. Construction typically 4-14 months.

Next Steps

Next steps for building an ADU in Louisville: 1. Review full ADU rules including size limits, setbacks, and parking. 2. Apply for an ADU permit through the Louisville Metro Planning and Design Services at https://louisvilleky.gov/government/construction-review. 3. Hire a licensed contractor familiar with KY ADU requirements.

Louisville Metro Planning and Design Services

Frequently Asked Questions