Horn Lake, MS Accessory Structures: ADU Rules (2026)

Mississippi has not enacted any statewide ADU statute requiring municipalities to allow accessory dwelling units. Under Miss. Code Ann. § 17-1-9 (the municipal zoning enabling act), Horn Lake's zoning power is exercised through its Zoning Ordinance (Appendix A of the Code of Ordinances), which defines districts, accessory uses, setbacks, lot coverage, and accessory building rules. Horn Lake also maintains Chapter 8 Building and Building Regulations covering permits and adopted construction codes. The city's Planning and Development Department (3101 Goodman Rd. W., 662-393-6705, plandept@hornlake.org) issues a Residential Accessory Building Permit application that is separate from the principal residential building permit. Because Horn Lake is an inland DeSoto County suburb of Memphis, applicants should confirm the current zoning district (typically R-1, R-2, or R-3 single-family / multi-family residential) controls the building's footprint, height, side- and rear-yard setbacks, and whether a detached structure may contain habitable living space. Accessory structures are subject to the city's adopted edition of the International Residential Code under Miss. Code Ann. § 21-19-25 (which authorizes Mississippi municipalities to adopt building, plumbing, electrical, and other codes by ordinance). For specific dimensional standards and whether a detached habitable unit (ADU/guest house) is permitted by right, conditional use, or prohibited in your zoning district, applicants must obtain the current Zoning Ordinance text from Municode and contact the Planning Department before designing.