Columbus ADU permit requirements
Last reviewed: June 22, 2026
Quick answer
Permitting an accessory dwelling unit (ADU) in Columbus, Ohio means pulling a building permit from the local authority that issues it. ArchPermit tracks 16 source-cited requirements (11 required, the rest conditional) for this jurisdiction. Submittals go through Columbus Citizen Access Portal. These requirements were last reviewed June 22, 2026; confirm the exact forms and fees with the local permitting authority.
A source-cited checklist of what an ADU (accessory dwelling unit) permit package needs in City of Columbus. Every item links to its authoritative source; items that vary are flagged to confirm locally.
As of ADU code changes effective Dec 24 2025, Columbus permits ADUs by-right in all residential and apartment-residential districts — no zoning variance for a conforming ADU (one ADU per lot generally; up to ~1,000 sf or 65% of the principal dwelling's net floor area, whichever is greater; max height 25 ft; lot coverage ≤65%; no added parking). BZS recommends a Preliminary Zoning Review to confirm conformance; a Board of Zoning Adjustment variance is required only if the project doesn't meet code. A building permit is always required. (By-right specifics come from BZS summaries + reporting; confirm against codified Title 33.)
- ADU Zoning Site Plan + Data Tablerequired
Zoning site plan with a Data Table: parcel #, lot sf, living area of primary vs ADU, ADU % of primary, heights, # units, % lot coverage, % rear-yard occupied, and required vs provided parking.
source · reviewed 2026-06-22 - Building Permit Applicationrequired
Completed BZS residential building-permit application (owner, applicant, contractor reg #, parcel, scope, sq ft, cost).
source · reviewed 2026-06-22 - Dwelling-Unit Tree Requirementrequired
The site plan must show the dwelling-unit (landscaping) tree requirement for the added unit.
source · reviewed 2026-06-22 - Electrical Planrequired
Receptacle, switch, light, fan, smoke-detector, and panel locations; service-load calculations if adding load.
source · reviewed 2026-06-22 - Energy Conservation Compliancerequired
Plans must convey the energy-code-compliance method (Prescriptive, Home Builders Association method, or REScheck).
source · reviewed 2026-06-22 - Floor Plans (every floor)required
Layout of every floor where work occurs; every room labeled; scaled or dimensioned; new vs existing differentiated.
source · reviewed 2026-06-22 - Mechanical (HVAC) Planrequired
Furnace, A/C unit, and gas-meter locations; ventilation; gas piping and prefab-fireplace details.
source · reviewed 2026-06-22 - Plot Plan / Site Planrequired
Site plan with dimensions to property lines and other structures; scaled and north-oriented.
source · reviewed 2026-06-22 - Plumbing Planrequired
New fixture locations; drain/stack/water-service/distribution sizes; pipe materials; fixture schedule; tie-in points.
source · reviewed 2026-06-22 - Scope of Workrequired
Bullet-point list of exactly what is planned, divided into Structural, Electrical, Mechanical, and Plumbing.
source · reviewed 2026-06-22 - Two (2) Complete Sets of Plansrequired
Two complete plan sets; incomplete submittals are rejected.
source · reviewed 2026-06-22 - Board of Zoning Adjustment (BZA) Variance Applicationconditionalverify locally
Required only if the ADU does not meet by-right code (e.g. setback/height/second ADU). By-right status (eff. 12/24/2025) confirmed via reporting; not yet verified against codified Title 33.
source · reviewed 2026-06-22 - Certificate of Appropriatenessconditional
Required before the permit if the property is in a historic district, commission area, East Franklinton Overlay, or University Impact District.
source · reviewed 2026-06-22 - Fire Separation Wallsconditional
Required on plans for 2 & 3 family dwellings, or for any wall less than 5 ft from a property line.
source · reviewed 2026-06-22 - Preliminary Zoning Reviewconditional
Recommended pre-step: a Zoning Review form + site plan emailed to confirm conformance / identify needed variances.
source · reviewed 2026-06-22 - Property Owner's Building Permit Affidavitconditional
Required only when the property owner (not a licensed contractor) is the permit holder.
source · reviewed 2026-06-22