Topeka, KS Accessory Structures: ADU Rules (2026)
ADU rules in Topeka, KS, also called accessory dwelling unit regulations or granny flat ordinances, cover setbacks, owner-occupancy, parking, and permit requirements.
Key Facts
- Governing section
- TMC § 18.225.010(mm)
- Size cap (detached)
- 800 sq ft or 50% of home
- Occupancy rule
- owner must live on-site
- Extra parking
- 1 off-street space required
Summary
Topeka allows one accessory dwelling unit per lot as an accessory use to a single-family home, capped at 800 square feet, with the owner required to live in either the ADU or the principal dwelling.
(mm) Accessory Dwelling Unit (ADU). (1) Generally. A single ADU is permitted as an accessory use to the principal dwelling and allowed subject to satisfying these standards. ... (4)(ii) Detached accessory dwellings shall contain no more than 800 square feet, exclusive of garages attached to the accessory dwelling, or 50 percent of the gross floor area of the principal dwelling, whichever is less. ... (5) Owner Occupancy Required. Either the accessory dwelling unit or the principal dwelling unit shall be occupied by an owner of record of the property.
Official source re-checked September 8, 2026: no newer edition of the code had been published (publisher’s edition: current through Ordinance 20671, passed July 14, 2026).
Full Breakdown
TMC § 18.225.010(mm) permits a single accessory dwelling unit, integrated into or detached from the principal home, as an accessory use in districts where the use table in TMC 18.60.010 lists ADUs with approval level 'S/C.' Detached ADUs top out at 800 square feet or 50 percent of the principal dwelling's floor area, whichever is smaller; integrated ADUs are capped at 800 square feet and 80 percent of the principal dwelling's area. Either the ADU or the principal home must be owner-occupied, one off-street parking space is required beyond what the main house needs, and the term is defined at TMC § 18.55.010. Applies inside Topeka, Shawnee County, Kansas.
Violations & Fines
Building an ADU larger than the size cap, skipping the owner-occupancy requirement, or failing the design-compatibility standards violates TMC § 18.225.010(mm) and can be denied a permit or require a conditional use permit under Chapter 18.215 TMC.
Frequently Asked Questions
Can I rent out both my house and my Topeka ADU to tenants?
How big can a detached ADU be in Topeka?
Sources & Official References
Other rules in Topeka
How Topeka compares: Easiest Cities to Build an ADU·Compare Topeka to another location·View the Kansas accessory structures overview
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