ADU rules in Lawrence

Lawrence allows an ADU in or above a detached accessory building, such as a garage, as a permitted accessory use ("A") in the R-1, R-2, R-3, R-4, R-5, M-1 and M-2 districts under Table 20-8-2 of the Land Development Code (LDC, Chapter 20). The ADU must be accessory to a single unit detached dwelling (20-811(b)(2)), and detached dwellings are currently permitted only in R-1 through R-4, M-1 and M-2 (Table 20-8-1), so in practice ADUs belong to house lots in those six districts. ADUs are not allowed in M-3, CC, CD, IL, IG, IBP, P-1 or P-2. The 2024 LDC (effective April 1, 2025) replaced the old RS-district-only rule.

Interior and attached ADUs are allowed in the same districts (R-1 through R-5, M-1, M-2) as accessory to a single unit detached dwelling. Section 20-811(b)(6)(C) expressly covers "an interior or attached accessory dwelling unit" and lets an attic or basement ADU take up the whole floor level. Only one entrance may face the street on the front facade unless a second street-facing entrance already existed (20-811(b)(6)(B)).

There is no fixed square-foot cap. An interior or attached ADU may be no more than 50 percent of the gross floor area of the dwelling it sits in, except that an attic or basement ADU may occupy that entire level if the space is not being expanded at the same time (20-811(b)(6)(C), (C)(i)). An ADU in or above a detached structure such as a garage may take 100 percent of that structure's floor area, provided it meets the district's dimensional standards (20-811(b)(6)(C)(ii)): in R-1 through R-5 an accessory building may be at most 25 ft tall or the height of the principal building, whichever is less, with accessory setbacks of 5 ft interior side and 5 ft rear (0 ft on an alley), and principal building coverage limits (40 percent in R-1). The old 960 sq ft and 33 percent caps belong to the repealed 2006 code.

The default rule is ongoing owner occupancy: either the house or the ADU must be occupied by a record owner (20-811(b)(4)(A)), and the registration affidavit must name which unit the owner occupies and be refiled if the owner moves to the other unit (20-811(b)(8)(B)). If neither unit is an owner's principal residence, the ADU may not house anyone and the owner faces enforcement, unless (1) the lot is designated permanently affordable, or (2) the ADU is attached to the house and the owner could legally have created a two-unit dwelling when the ADU was created (20-811(b)(4)(B)). Because two-unit dwellings are permitted in R-1 through R-4, M-1 and M-2 on qualifying lots, many attached ADUs escape the rule; detached ADUs stay owner-occupied. Kansas has no state owner-occupancy preemption.

Section 20-811(b)(7) sets three cases. No additional space is required when the lot abuts only a local street whose pavement is at least 27 feet wide. One additional space is required when the lot abuts only a local street narrower than 27 feet, or when the ADU is created at the same time as the principal dwelling. One additional space is required when the lot abuts only a collector or arterial street. The section does not address corner lots fronting both a local street and a collector or arterial.

ADUs are a by-right accessory use ("A" in Table 20-8-2), handled administratively: the ADU must be registered with the Planning Director before it is established, with a recorded affidavit pledging compliance (20-811(b)(8)(A)-(B)), and permits may issue once planning staff determine the proposal complies with the LDC (20-811(b)(8)(C)), followed by an ordinary building permit. There is no hearing. This is consistent with 2026 Kansas SB 418, Sec. 1(c)(1), which requires ADUs meeting the zoning criteria to be "approved by-right, without the need for discretionary review" and deems complete applications approved unless denied within 30 days (Sec. 1(c)(2)).

Renting any dwelling unit to a non-owner for 30 days or more requires a city rental license per unit, with an annual fee and inspections (City Code Secs. 6-1303, 6-1304, 6-1310), unless the unit is occupied by the owner or the owner's immediate family (Sec. 6-1326(a)). Short-term rentals (under 30 days) need a short-term rental license and inspection (Secs. 6-1353(a), 6-1354). Non-owner-occupied short-term rentals cannot be licensed in R-1, R-2 or PD districts (Sec. 6-1353(c)), and the LDC's accessory use table bars them in R-1 and R-2 (Table 20-8-2, as amended by Ord. 10208, April 14, 2026); an ADU in those districts may be a short-term rental only if the lot is owner-occupied and the ADU is lawful (Sec. 6-1353(d)). A World Cup exception lifted these limits for May 25 to July 25, 2026 (Ord. 10153); Ord. 10195 restored them from July 26, 2026. No one may hold more than three short-term rental licenses (Sec. 6-1353(b)). No rule bars selling an ADU separately, but it must stay on the same lot as the house.