Willoughby

Lake County has NOT adopted a countywide zoning resolution under O.R.C. Chapter 303. The Lake County Planning Commission (105 Main Street, Building B, Floor 4, Painesville, OH 44077; 440-350-2740) does not exercise zoning authority over unincorporated territory; its statutory roles are (a) enforcement of the Lake County Subdivision Regulations (as amended January 29, 2013, with 2020 cover update), (b) advisory review and recommendation on township zoning text and map amendments, (c) preparation of the county land-use plan, and (d) staff support for the Land Use & Zoning Committee. Land-use authority over ADUs rests at the TOWNSHIP level (O.R.C. Chapter 519) for the five civil townships — Concord, Leroy, Madison, Painesville, and Perry — and at the MUNICIPAL level for the nine cities (Eastlake, Kirtland, Mentor, Mentor-on-the-Lake, Painesville, Wickliffe, Willoughby, Willoughby Hills, Willowick) and the nine villages (Fairport Harbor, Grand River, Kirtland Hills, Lakeline, Madison, North Perry, Perry, Timberlake, Waite Hill). Each township and municipality adopts its own zoning resolution or zoning code; ADU permissibility, dimensional standards, parking, and owner-occupancy rules vary jurisdiction by jurisdiction. There is no county-side ADU ordinance to cite — the operative ADU rule for any given parcel is decided at the township-trustee or city/village-council level. Concord Township's zoning resolution (most recently amended September 5, 2025) and Painesville Township's resolution (Section XIV R-1 and Section XV R-2, effective 2021-02-18) are representative township codes that researchers will encounter; both treat accessory uses as 'clearly incidental and secondary' to the principal residential use, which typically means a habitable second dwelling unit requires a conditional-use hearing before the township Board of Zoning Appeals unless the resolution specifically authorizes ADUs as a permitted use.

• O.R.C. Chapter 303 - County rural zoning (not adopted by Lake County)
• O.R.C. Chapter 519 - Township zoning
• O.R.C. § 711.10 - County subdivision regulations (Lake County Subdivision Regulations adopted thereunder)
• Lake County Subdivision Regulations (as amended January 29, 2013; 2020 cover update)
• Concord Township Zoning Resolution (as amended September 5, 2025)
• Painesville Township Zoning Resolution Sections XIV (R-1) and XV (R-2) (effective 2021-02-18)

State-floor overlay: Ohio has no statewide ADU preemption (see state-level research). Construction is governed by the Residential Code of Ohio (RCO) for one-, two-, and three-family dwellings under O.R.C. § 3781.10 and OAC 4101:8, enforced through the Lake County Building Department (which the Ohio Board of Building Standards has certified to enforce the RCO countywide). The Ohio Department of Health regulates Household Sewage Treatment Systems under OAC Chapter 3701-29, with local enforcement at the Lake County General Health District Operation & Maintenance Program. There is no state-imposed floor on ADU permissibility, parking, owner-occupancy, or size; those decisions are made at the township or municipal level.

Lake County's overlay-style constraints that meaningfully affect ADU siting are: (1) the FEMA NFIP Special Flood Hazard Areas covering the Grand River and Chagrin River corridors, Mentor Marsh, and the Lake Erie shoreline backwater zones - each participating jurisdiction (county, township, city, village) administers its own floodplain ordinance for parcels in mapped SFHAs; (2) Lake Erie Coastal Erosion Areas designated by the Ohio Department of Natural Resources Office of Coastal Management, which apply along the county's 31-mile Lake Erie shoreline (Lake County has the longest lakefront of any Ohio county) - parcels in a designated Coastal Erosion Area face additional shoreline-development restrictions and erosion-control permitting under Ohio Coastal Management Program rules; (3) Lake Metroparks holdings (more than 8,100 acres across 36 distinct park areas, including Mentor Lagoons Nature Preserve & Marina, Headlands Beach State Park-adjacent reserves, and lakefront properties) - Park-District-owned parcels are not developable and adjacent parcels may face setback constraints; (4) Mentor Marsh State Nature Preserve and Holden Arboretum (Kirtland, 3,500 acres) as major non-developable open-space holdings that constrain adjacent land use; (5) the Chagrin River Watershed Partners (CRWP) model riparian-setback regime, which Concord and several other Lake County townships and villages have adopted via CRWP model ordinances and which can require 75-300 ft riparian setbacks from the Chagrin River and its tributaries; (6) the Lake County General Health District Operation & Maintenance Program for HSTSs (approximately 15,000 systems countywide; fees $40-$160 per term; all systems enrolled) - an ADU on a private-septic parcel typically triggers a system-capacity review by LCGHD Environmental Division and frequently requires drainfield enlargement or advanced-treatment upgrade; (7) Ohio EPA Phase II Stormwater jurisdiction administered by the Lake County Soil and Water Conservation District for any construction site disturbing one acre or more, plus the Lake County Stormwater Management Department's site grading and drainage plan review for participating member communities; (8) CAUV-enrolled agricultural land (most concentrated in Leroy, Madison, and Perry Townships), where conversion to non-agricultural use to site an ADU triggers three-year recoupment under O.R.C. § 5713.34.

• FEMA NFIP Special Flood Hazard Areas - Grand River, Chagrin River, Mentor Marsh, Lake Erie shoreline backwater zones — An ADU built inside an SFHA must meet 44 CFR 60.3 standards: lowest-floor elevation at or above Base Flood Elevation (BFE), flood vents, anchoring, and post-construction Elevation Certificate filing. The Lake Erie shoreline corridor is particularly sensitive because 2019-2020 record-high Lake Erie water levels expanded the practical inundation footprint beyond mapped SFHA boundaries; conservative siting is advised even outside formal Zone A/AE lines on lakefront parcels.
• Ohio Coastal Erosion Areas (Lake Erie shoreline) — An ADU project on a lakefront Lake County parcel must screen for CEA designation early. The 30-year erosion projection effectively prohibits new construction (including ADUs) inside the projected loss zone unless robust erosion-control infrastructure is in place. The Office of Coastal Management (419-626-7980) provides parcel-specific CEA determinations. ODNR has favored nature-based shoreline approaches in recent guidance; hard-armoring designs require additional Shore Structure permitting.
• Lake Metroparks holdings and adjacent setback considerations — ADU projects on parcels adjacent to a Park District holding should check for any recorded conservation easement that runs with the seller's parcel - some easements limit second-dwelling-unit construction even on the unencumbered host parcel. Lake Metroparks staff can confirm easement status by parcel number.
• Mentor Marsh State Nature Preserve and Holden Arboretum — ADU projects on parcels adjacent to Mentor Marsh face wetland-setback review under federal Clean Water Act Section 404 if the project touches a delineated wetland boundary. Holden Arboretum's perimeter parcels (Kirtland Hills, Waite Hill, north Kirtland) carry no direct overlay but local zoning in those municipalities tends to enforce large minimum lot sizes (1-5+ acres) that effectively reshape ADU economics.
• Chagrin River Watershed Partners (CRWP) model riparian-setback ordinances — An ADU project on a Chagrin Valley parcel in Lake County should be screened early for CRWP riparian-setback compatibility - the setbacks can effectively foreclose ADU siting on small riparian lots. The exact setback depends on the jurisdiction's adopted version of the ordinance and the stream order of the watercourse on or near the parcel.
• Lake County General Health District HSTS Operation & Maintenance Program — HSTS capacity is frequently the rate-limiting step on a rural Lake County ADU project, not zoning or building permit. Owners should engage LCGHD Environmental Division (440-350-2543) early for a system-capacity determination before committing to ADU design and bedroom count. Plumbing permits for private-septic parcels are issued by LCGHD, not by the Lake County Building Department.
• Ohio EPA Phase II Stormwater Program (Lake SWCD administered) — For most stand-alone ADU projects, Phase II is not triggered. For projects that combine ADU construction with substantial site work (new private drive, large septic-system replacement, lot clearing), engage Lake SWCD early to confirm whether the aggregated disturbance crosses one acre.
• CAUV-enrolled agricultural land (O.R.C. § 5713.30 / § 5713.34) — CAUV recoupment is a material project cost on an ADU built on previously CAUV-enrolled land. Owners should run the recoupment calculation with the Auditor's CAUV staff before committing to siting an ADU on CAUV acreage rather than on a separate non-CAUV residential parcel.

The Lake County Building Department (105 Main Street, Building B, 2nd Floor, Painesville, OH 44077; phone 440-350-2636 or 1-800-899-5253; office hours 8:00 AM - 4:30 PM weekdays) is the State-certified building department enforcing the Residential Code of Ohio (2019 RCO for one-, two-, and three-family dwellings; OAC 4101:8) and the Ohio Building Code countywide. Dave Strichko is the Chief Building Official. Permit applications are submitted via the online document portal at bisubmittal.lakecountyohio.gov/DocUpload/, via email, or via drop box at the entrance of 105 Main Street. The department issues four parallel residential permit types - Residential Building, Residential Electric, Residential Mechanical (HVAC, fuel gas, hydronics, refrigeration), and Residential Plumbing - any of which an ADU project will trigger. Crucially, the Lake County Building Department serves as the CONSTRUCTION-CODE enforcement body across the county, but ZONING approval is a separate prerequisite that must be obtained from the township, city, or village of jurisdiction; the county does NOT enforce zoning. Septic permits and HSTS Operation & Maintenance permits are issued separately by the Lake County General Health District (5966 Heisley Road, Mentor, OH 44060; 440-350-2543). Construction-site stormwater erosion control is administered by the Lake County Soil and Water Conservation District for sites disturbing one acre or more (Ohio EPA Phase II Stormwater NPDES general permit), and site grading and drainage plan review is performed by the Lake County Stormwater Management Department (105 Main Street, Suite A305, Painesville; 440-350-5900) for participating member communities; properties in Leroy Township are directed to the Lake County Engineer's office for those reviews.