The City of Columbus has released a new handbook for residents interested in building an Accessory Dwelling Unit (ADU) on their property. Posted online last month with little fanfare, the new document lays out existing regulations and requirements for the structures, which are generally defined as smaller housing units built on the same lot as an existing home.
Produced by California-based Opticos Design, the new handbook contains photos and graphics, as well as a detailed breakdown of the different factors homeowners might need to consider when planning to construct an ADU.
Otto Beatty – who was appointed to City Council in January of 2025 and served through the end of the year – advocated for its creation as part of a larger push that culminated in the passage of legislation last fall to legalize ADUs in residential neighborhoods throughout the city.
The legislative changes were meant to make it easier for homeowners to build an ADU on their property by simplifying the process, which before typically involved applying for multiple zoning variances. Housing advocates generally applauded the legislation, and have also voiced support for the handbook.
“We are very excited to see the city provide formal step-by-step guidance on the process of ADU construction,” said Stewart Weinland, Chair of Strong Towns Columbus. “As a relatively rare form of gentle density in the city, anything we can do to reduce the friction of building one can be a tremendous help.”
Questions Raised About Sewer Connections
A recent report from the Greater Ohio Policy Center (GOPC) suggests that one common barrier for homeowners looking to build an ADU – the cost of connecting it to sewer and water service – tends to be significantly higher in Columbus than in many other cities.
“We determined that the primary sewer configuration allowed for ADUs in peer cities is not permitted in Columbus and that the inability to use the alternative configuration is likely to increase sewer costs associated with ADUs here,” said Jason Warner, Director of Strategic Engagement for GOPC.
While the other cities they examined allow ADUs to connect their water and sewer lines directly to the primary house on the lot, Columbus requires that ADUs connect to the main public sewer via their own separate line, known as a lateral. This is due to a specific section of Columbus’ city code, as well as the way city staff interpret state code, according to the report.
“Early evidence suggests the potential cost savings of the peer city sewer configuration could be significant and possibly be the difference between a financially feasible and infeasible ADU project,” said Warner.
Weinland, of Strong Towns Columbus, said that the report highlights an important issue.
“Other cities allow connections within the primary residence – so far without any catastrophic effects – and the shortest path to a sewer (and water) connection is almost always through the primary residence,” he said. “We know the city is serious about eliminating barriers to housing products that help its residents build wealth, so making ADU construction cheaper by allowing this already-proven strategy sure looks like a no-brainer to us.”
Alison Goebel, GOPC’s Executive Director, told CU that her team worked closely with city staff to make sure they understood the current rules and how they are interpreted, and that they also held a briefing with city officials after it was the report was completed to discuss its findings. Although no firm commitments were made, Goebel said that the officials indicated a willingness to take a closer look at the issue of sewer connections in the future.
Changes could also potentially be made legislatively, she said, via amendments to the plumbing and housing codes.
To see the full report, titled “Investigation of ADU Sewer Requirements in Columbus, OH,” visit www.greaterohio.org.
https://columbusunderground.com/adu-update-city-releases-new-handbook-advocates-push-for-more-changes-bw1/