Breaking: Columbus Approves Accessory Dwelling Units (ADUs)

A New Era for Columbus Housing

On November 24, 2025, Columbus City Council passed legislation allowing accessory dwelling units (ADUs) by right in all residential and apartment residential districts.¹ The change removes the routine variance path that previously required months of hearings and approvals. The adopted rules took effect on December 24, 2025.

This is part of the broader Columbus Forward initiative aimed at addressing the city’s housing shortage. Columbus has a significant deficit of affordable housing,² and ADUs represent one tool for adding supply without dramatically changing neighborhood character.

In drafting the legislation, the City sought input from design professionals with ADU experience. We were among those consulted, reviewing the draft legislation and providing feedback before the Council vote. This kind of collaboration between policymakers and practitioners helps ensure that housing policy works in practice, not just on paper.

Earlier this year, we presented on this very topic at the AIA Ohio conference, walking through what’s happening in Columbus neighborhoods, what’s changing inside City Hall, and how architects, homeowners, and small developers can make good projects pencil. The legislation that passed this week is exactly what we were anticipating.

What Changed

Under the previous system, building an ADU required a variance, which meant neighborhood meetings, City Council presentations, and months of waiting.

The new legislation streamlines this process. An ADU that meets the adopted standards can move through the standard zoning and building approval process without a routine zoning variance.

Key Requirements

• Maximum size: 65% of the primary dwelling’s net floor area or 1,000 square feet, whichever is greater, without exceeding the primary dwelling
• Maximum height: The height of the primary dwelling or 25 feet, subject to the code’s existing-building exception
• Lot coverage: Up to 65% on a lot with an ADU
• Parking: No additional parking required
• Eligible zones: All residential and apartment residential districts, subject to the adopted standards

Source: Columbus Underground

Gentle Density: More Neighbors, Same Neighborhood

The phrase that anchors the ADU conversation is “gentle density.” ADUs increase housing supply without changing a street’s overall character or forcing major infrastructure upgrades. You’re building on an existing lot, tapping existing services, and preserving the front house that already tells the street’s story.

If you’re trying to grow a city responsibly, that’s a powerful approach: more options, more affordability, and more neighbors without turning every block into a construction zone or a parking debate.

Who Benefits from ADUs in Columbus?

The short answer is pretty much everyone. The longer answer breaks down by audience:

• Young families and first-time buyers: Rental income from a carriage house can make a mortgage in a strong school district attainable.
• Young professionals and remote workers: A self-contained home office or studio solves the “working out of the bedroom” problem.
• Empty nesters: Downsize into a right-sized ADU and rent the primary home to stay rooted in your neighborhood.
• Aging parents: Multi-generational living with dignity and proximity, common globally, increasingly normal here.
• Investors and owner-occupants: Lower barrier to entry than buying a whole multifamily; diversified rental strategy options with a manageable footprint.

Where ADUs Make the Most Sense

Not every property is equally suited for an ADU. The best candidates typically share several characteristics:

• Existing structures: Detached garages, especially two-car garages, offer conversion opportunities
• Alley access: Rear access simplifies construction logistics and provides separate entry
• Adequate yard space: Room for a detached structure while meeting setback requirements

Neighborhoods like Clintonville and other Columbus residential areas with larger lots and alley access are well-positioned for ADU development.

Historic Districts: Additional Considerations

The zoning change applies in residential and apartment residential districts, but properties in German Village, Victorian Village, Italian Village, and other historic districts remain subject to applicable architectural-review requirements. A project may still need a Certificate of Appropriateness from the relevant commission before construction. This design review helps new work respond to the established neighborhood character.

For homeowners in historic districts, working with professionals experienced in historic preservation can help navigate the COA process and ensure the final design meets commission standards.

The Path Forward

The city expects to release an ADU guidebook in early 2026 with detailed requirements and best practices. In the meantime, homeowners interested in exploring ADU options should:

1. Verify their property’s zoning classification
2. Assess lot size and existing structures
3. Research local rental rates for comparable units
4. Consult with architects or designers experienced in ADU projects

The legislation represents a meaningful shift in how Columbus approaches housing. While ADUs alone will not solve the city’s housing shortage, they provide homeowners with new options and contribute to a more flexible housing stock, one property at a time.

Sources

1. City of Columbus Building and Zoning Services - ADU Legislation Effective December 24, 2025

2. COHHIO 2025 Gap Report - Shows Shortage of Affordable Homes in Ohio

3. Columbus Underground - City Council Legalizes Accessory Dwelling Units in Residential Districts

4. Columbus Business First - City Council Passes ADU Legislation