Tippecanoe committee votes to send proposed ADU size changes to full commission

The Tippecanoe County Area Plan Commission Ordinance & Bylaw Committee voted Jan. 7 to forward amended accessory dwelling unit (ADU) size rules to the full commission in ordinance form after extended discussion about rural and urban impacts.

Nathan McBurnett, APC staff, reopened the topic as a continuing discussion and said the change was prompted by an increasing number of residents seeking ADUs and by a desire to encourage by-right development rather than require frequent variances. "We've gotten an increasing amount of attention from people who wanna do ADUs," McBurnett said, noting many applicants were constrained by the current 750-square-foot cap.

Committee members debated several approaches, including fixed caps of 1,000 to 1,500 square feet and percentage-based limits tied to the primary dwelling. Members discussed practical scenarios (garage-located units, basement units and detached guest houses), septic and utility connections (which the health department governs), and whether a larger unit would effectively become a second principal dwelling.

After debate, a motion (restated by staff) set the ADU maximum as the lesser of 1,200 square feet or 50% of the primary dwelling's gross floor area; the motion also included an exception that an ADU located in the basement of the primary dwelling may use the entire building footprint. Nathan McBurnett restated the motion in the meeting: "The motion is the lesser of 1000 square feet or 50% of the ground floor area of the primary dwelling unless it's in the basement of a primary dwelling then it would be the entire square footage ground floor area," and the committee amended language to place a definition cap of 1,200 square feet and clarify the basement exception.

The committee voted by voice to send the amended language to the full commission in ordinance form. Committee members said the change aims to balance flexibility for property owners with limits intended to prevent the creation of what amounts to a separate single-family house without going through standard subdivision or building-permit processes.

The full Area Plan Commission will consider the ordinance draft and schedule a public hearing; committee members indicated the draft will incorporate a 1,200-square-foot definition cap, a 50% GFA percentage limit in chapter 4, and the basement-footprint exception.

Next steps: Staff will prepare ordinance language for the full commission and public notice; a formal public hearing and additional review are expected during the commission's forthcoming meetings.