ADU Rules in Lexington, KY (2026)
ADU rules, permit requirements, size limits, and fees for Lexington, KY. Source-cited from official municipal code.
Yes, ADUs are allowed in Lexington, KY.
Lexington, KY permits accessory dwelling units (ADUs) on residential properties. ADUs — also called granny flats, in-law units, backyard cottages, or secondary suites — are secondary housing units on a single-family or multifamily lot. State and local law governs the approval process. In Lexington, the Lexington-Fayette Urban County Government Division of Building Inspection handles ADU permit applications. Below you will find the current size limits, setbacks, fees, and timeline for building an ADU in Lexington.
ADU Size Limits
ADU Size Limits in Lexington: Detached ADU: up to 850 sq ft (max height: 25 feet). Attached ADU: 40% of primary dwelling floor area. LFUCG Zoning Ordinance accessory dwelling unit provisions. Detached ADUs allowed up to 850 sqft in qualifying R zones. JADU is a California-specific concept not applicable in Kentucky.
| Type | Max Size | Max Height |
|---|---|---|
| Detached ADU | 850 sq ft | 25 feet |
| Attached ADU | 40% of primary dwelling floor area | Per zone height limit |
Permit Fees
ADU Permit Fees in Lexington: Plan check fee: $150–$800. Building permit fee: Based on construction value — typically $600–$2,800. Impact fees: LFUCG charges utility connection fees through Kentucky Utilities (KU) and Kentucky American Water. School fees: None or N/A. Total estimated permit cost: $1,800–$7,000 total fees. LFUCG permit fees are moderate. Kentucky American Water and Kentucky Utilities (KU) connection fees apply for new utility service connections.
| Fee Type | Amount |
|---|---|
| Plan Check | $150–$800 |
| Building Permit | Based on construction value — typically $600–$2,800 |
| Impact Fees | LFUCG charges utility connection fees through Kentucky Utilities (KU) and Kentucky American Water |
| School Fees | None |
| Total Estimate | $1,800–$7,000 total fees |
Permit Timeline
Lexington ADU Permit Timeline: LFUCG Division of Planning permit: typically 4-7 weeks for residential permits. Construction typically 4-12 months. Apply through the Lexington-Fayette Urban County Government Division of Building Inspection online permit portal. Phone: (859) 425-2255.
Setback Requirements
ADU Setback Requirements in Lexington: Front setback: follows zone standard. Side setback: 5 feet. Rear setback: 5 feet. LFUCG Zoning Ordinance ADU setbacks. Minimum 5 ft rear and side setbacks for detached ADUs in R zones.
Parking Requirements
Parking Requirements: 1 parking space required per ADU. Lexington has limited public transit — LexTran bus service is available. No parking waivers for transit proximity in most residential zones.
Restrictions & Requirements
- ADU must be on same lot as primary single-family dwelling
- Lot must meet minimum size requirements for the R zone
- ADU cannot be separately conveyed from primary parcel
- Total lot coverage must comply with LFUCG zone limits
- Properties in Rural Service Area (outside Urban Service Area) have different rules
- STR registration required if ADU used for short-term rental
- Must comply with Kentucky Residential Building Code
How Many ADUs Are Allowed?
Number of ADUs Allowed in Lexington: Single-family lots: 1 ADU per single-family lot within the Urban Service Area. Multifamily properties: Additional units permitted in R-3 and R-4 zones. Lexington's Urban Growth Boundary (Urban Service Area) limits development in the Bluegrass horse farm region. ADU allowances apply within the Urban Service Area where full utility services are available.
Single-Family Lots
1 ADU per single-family lot within the Urban Service Area
Multifamily Properties
Additional units permitted in R-3 and R-4 zones
Historic District Considerations
Historic District Requirements: Lexington has 15 historic districts where additional design review may be required for ADU construction. Design review approval is required before obtaining a building permit for properties in historic overlay zones. Lexington has significant historic resources including Gratz Park (one of Kentucky's oldest neighborhoods), Woodland-Ashland Avenues Historic District, Chevy Chase, and the UK campus-adjacent Fort Hill neighborhoods. Lexington-Fayette County Historic Preservation Commission designates local landmarks and historic zones. Certificate of Appropriateness may be required for exterior changes to contributing structures. Look up historic district boundaries at: https://www.lexingtonky.gov/historic-preservation
Frequently Asked Questions
Can I build an ADU in Lexington?
Yes. Lexington, KY allows accessory dwelling units. On a single-family lot you can build 1 ADU per single-family lot within the Urban Service Area.
How big can an ADU be in Lexington?
The maximum size for a detached ADU in Lexington is 850 square feet.
How long does it take to get an ADU permit in Lexington?
The typical ADU permit timeline in Lexington is LFUCG Division of Planning permit: typically 4-7 weeks for residential permits. Construction typically 4-12 months.. Total estimated permit fees are $1,800–$7,000 total fees.
Do I need extra parking for an ADU in Lexington?
No, Lexington does not require additional parking for ADUs.
Do I have to live on-site to have an ADU in Lexington?
No, owner-occupancy is not required for ADUs in Lexington.
Source: LFUCG Zoning Ordinance — Accessory Dwelling Unit provisions. Last verified April 6, 2026. View source