Accessory dwelling unit permit — Louisville/Jefferson County, KY

Last updated: September 24, 2026

What affects the price

Building an ADU is a custom project, so costs vary based on your specific choices. Site conditions are the biggest factor; if your land requires significant grading, utility extensions, or foundation work, those expenses add up quickly. Choosing high-end finishes, custom cabinetry, or complex roof lines will also push the budget higher compared to a standard design. Prefabricated units often offer predictable costs, while custom site-built structures allow for more flexibility but can be harder to estimate upfront. Exact pricing confirmed free on the call.

About this service

An accessory dwelling unit permit is the mandatory approval required by your city to ensure your project meets local zoning and safety codes. You need this whenever you plan to add a secondary living space to your property. Factors affecting the cost include municipal filing fees and the level of engineering detail required for your plans. Exact pricing confirmed free on the call.

Frequently asked in Louisville/Jefferson County

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More on this: HUD ADU resources — ADU policy and financing research.

Service area details

Serving all of Louisville/Jefferson County — population 622,981.

Neighborhoods served in Louisville/Jefferson County: Old Louisville, Highlands, Germantown, Clifton, Crescent Hill, Downtown Louisville — and every surrounding area.