Can I Build ADU in Louisville, KY? (2026)
Find out if you can build a adu in Louisville, KY. Rules, permit requirements, costs, and next steps.
Yes, ADUs are allowed in Louisville, KY. California state law ensures by-right approval.
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/develop-louisville/permits. 3. Hire a licensed contractor familiar with KY ADU requirements.
Louisville Metro Planning and Design Services
Phone: (502) 574-3131
Website: https://louisvilleky.gov/government/develop-louisville
Online Permits: https://louisvilleky.gov/government/develop-louisville/permits
Frequently Asked Questions
What is Louisville-Jefferson County Metro Government and how does it affect permitting?
Louisville-Jefferson County Metro Government (Louisville Metro) was formed in 2003 when voters approved the merger of the City of Louisville and Jefferson County into a single consolidated government. This means one planning and permitting department — Louisville Metro Planning and Design Services — handles zoning, permits, and development for the entire Jefferson County area. You don't have to navigate city vs. county differences. This is similar to Nashville-Davidson County's consolidated structure.
Can I build an ADU on my Louisville property?
Yes. Louisville Metro allows accessory dwelling units on single-family lots under the Land Development Code. Maximum size is typically 900 sqft for detached ADUs. Kentucky has no statewide ADU law — Louisville Metro's local LDC governs. No owner-occupancy requirement. You'll need a building permit from Louisville Metro Planning and Design Services. MSD sewer connection fees and LG&E electrical connection fees apply for independent utility service.
What is Old Louisville and do I need special permits there?
Old Louisville is the largest contiguous preserved Victorian neighborhood in the United States — approximately 45 blocks south of downtown with over 1,400 Victorian-era structures. If your property is in Old Louisville or another locally designated historic district, you may need a Certificate of Appropriateness from the Louisville Landmarks Commission for exterior modifications. This includes roofing, window replacement, additions, and exterior alterations. Contact Louisville Metro Planning and Design Services to check your property's historic status.
What are Louisville's STR (Airbnb) requirements?
Louisville Metro requires a Short-Term Rental License for rentals of 30 days or fewer. Annual fee is approximately $250. License number must appear in all booking platform listings. Occupancy limits (2 per bedroom), noise ordinance, and safety equipment requirements apply. Kentucky's 1% state transient room tax plus Louisville Metro's 8.5% lodging tax apply to STR income.
Is Louisville in a flood zone?
Many Louisville properties near the Ohio River, Beargrass Creek, and other waterways are in FEMA-designated Special Flood Hazard Areas. The 1937 Ohio River flood was catastrophic for Louisville — the Ohio reached 57 feet above flood stage. Check the FEMA Flood Map Service Center for your property's designation. MSD (Metropolitan Sewer District) administers stormwater and floodplain management for Louisville Metro. Properties in SFHA require flood insurance with federally-backed mortgages.
Source: Louisville Metro Planning and Design Services — Building Regulations. Last verified April 6, 2026. View source