Sioux Falls's Accessory Structures: The Rules That Matter

Every city handles accessory structures a little differently. In Sioux Falls, South Dakota, there are 9 distinct rules that residents and property owners should be aware of. Some are stricter than what neighboring cities enforce, and others are more relaxed. Here is what you need to know.

Tiny Homes

Sioux Falls allows tiny homes (under 400 sq ft) on permanent foundations only as Accessory Dwelling Units (ADUs) under Code § 159.305, subject to ADU size caps, parking, and owner-occupancy rules. The city follows IRC Appendix Q (adopted with the 2021 IRC under Title 150). Tiny homes on wheels (THOWs) are treated as recreational vehicles and cannot be used as permanent dwellings on residential lots.

Key details: Code Sections: Sioux Falls Code § 159.305, Title 150 (2021 IRC Appendix Q). Tiny home definition (IRC): 400 sq ft or less, excluding lofts. Only allowed as: ADU on permanent foundation. Detached ADU size cap: 50% of primary dwelling. Tiny homes on wheels: Treated as RVs — no permanent residency.

Installing a tiny home as a stand-alone dwelling without ADU approval is a zoning violation. Living full-time in a tiny home on wheels parked on a residential lot triggers code enforcement under Title 153 and the building code. Fines under Title 130 can reach $500/day. Unpermitted utility connections add separate violations under Title 170.

ADU Owner Occupancy

Sioux Falls Code § 160.093 requires that one of the two dwelling units on an ADU lot be owner-occupied. Both units cannot be simultaneously rented to non-owner tenants.

Key details: Code Section: Sioux Falls Code § 160.093. Owner-Occupancy: Required for one of two units, continuously. Verification: Confirmed at residential rental permit issuance. State Preemption: None — local rule under home-rule charter. Compare: California GC §66317 prohibits owner-occupancy mandates; SD does not.

Failure to maintain owner-occupancy of one unit converts the property to an unauthorized two-family use in a single-family district, subject to zoning enforcement under § 160.999 (Class 2 misdemeanor for repeat violations) and possible loss of the rental permit under § 150.177.

This is one of the stricter rules in Sioux Falls's municipal code. If you are unsure whether your situation complies, it is worth checking with the city before proceeding.

ADU Rental Restrictions

An ADU may be rented in Sioux Falls but the unit must be registered under the citywide residential rental permit program (§ 150.177), effective January 1, 2024. Short-term rentals (under 30 days) face additional state lodging-license and sales-tax requirements.

Key details: Rental Permit Required: Yes — § 150.177 (effective Jan 1, 2024). STR Definition: >14 rental days/year while not owner-occupied. Long-Term Training: Mandatory 2-hour city-approved course. STR State Licenses: SD sales tax license + state lodging license. Lodging Tax Total: ~8.7% (4.2% state + 2% city + 1.5% tourism + 1% BBB).

Renting an unpermitted ADU is enforceable under § 10.999. Effective July 1, 2024, a person who advertises, solicits for, or permits occupancy of an unpermitted long- or short-term rental may face a fine of up to $500 and up to 30 days in the Minnehaha County Jail per violation.

ADU Permits

Constructing an ADU in Sioux Falls requires a standard building permit from Building Services. Permit fees are based on the project's construction valuation under the city fee schedule; no separate ADU-specific permit type exists.

Key details: Permit Authority: Sioux Falls Building Services Division. Permit Type: Standard residential building permit (no conditional use required). Code Adopted: 2021 IRC (Title 50). Certificate of Occupancy: Required under § 160.726. Fee Basis: Construction valuation per city fee schedule.

Building without a permit is enforceable under Sioux Falls Code § 150.999 (building code penalties) and may trigger stop-work orders, double-fee retroactive permits, and removal of unpermitted work. Occupying an ADU without a certificate of occupancy violates § 160.726.

ADU Impact Fees

Sioux Falls does not levy a separate ADU impact fee. South Dakota does not have a statewide development-impact-fee enabling statute, and Sioux Falls funds infrastructure through general permit valuation fees, water/sewer connection fees, and the municipal sales tax (SDCL Chapter 10-52).

Key details: ADU Impact Fee: None — not authorized by SD statute. Building Permit Fee: Valuation-based per city fee schedule. Utility Tap Fees: Apply if new water/sewer service required (Title 170). Infrastructure Funding: 2% municipal sales tax (SDCL 10-52), second-penny CIP. Statutory Authority: No SD impact-fee enabling statute exists.

Failure to pay required permit, plan-review, or utility connection fees prevents permit issuance and certificate of occupancy under § 160.726. There are no impact-fee-specific enforcement provisions because the city does not levy impact fees.

If you are coming from a city with tighter rules, you will find Sioux Falls gives residents more flexibility on adu impact fees.

Carport Rules

Carports in Sioux Falls require a building permit and are regulated as accessory structures under Code § 160.093. They are prohibited in the required front-yard setback and must meet the same side/rear setbacks as detached garages. Carports cannot replace required enclosed garage parking in zones that mandate it and must be permanently anchored.

Key details: Code Sections: Sioux Falls Code §§ 160.093 & 160.553. Building permit: Required regardless of size. Front-yard placement: Prohibited in required front-yard setback. Rear-yard setback: 2 ft if >10 ft from house. Max height: 16 ft (one story).

Erecting a carport without a building permit is a municipal violation subject to a stop-work order and fines under Sioux Falls Title 130 (up to $500/day). Carports placed in front-yard setbacks or within prohibited setback areas can be ordered removed by Code Enforcement.

Shed Rules

Sioux Falls requires a permit for every shed regardless of size. Sheds 200 sq ft or less get a simplified zoning placement permit; sheds over 200 sq ft must meet full residential building code. In rear yards more than 10 ft from the house, sheds can sit as close as 2 ft from the side/rear property line under Sioux Falls Code Title 16 (§160.093 Accessory Uses).

Key details: Code Section: Sioux Falls Code § 160.093 (Accessory Uses). Permit-exempt size: None — all sheds need at least a placement permit. 200 sq ft threshold: Over 200 sq ft triggers full residential building code. Rear-yard setback: 2 ft from side/rear if >10 ft from house. Max height: 16 ft (one story).

Building without the required placement permit or building permit is a municipal code violation; Code Enforcement can issue a stop-work order and require removal or relocation if setbacks are violated. Fines for zoning violations in Sioux Falls run up to $500 per day under the home-rule penalty schedule (Title 130). Sheds in the floodplain built without elevation can trigger FEMA NFIP compliance action.

Garage Conversions

Converting a garage into livable space in Sioux Falls requires a building permit and triggers the city's Accessory Dwelling Unit (ADU) rules under Code § 159.305 if you create an independent dwelling unit. ADUs are limited to 75% of the primary home's floor area (attached) or 50% (detached), require 2 extra off-street parking spaces, and demand owner-occupancy of either the main home or the ADU.

Key details: Code Section: Sioux Falls Code § 159.305 (Accessory Dwelling Units). Attached ADU size cap: 75% of primary dwelling floor area. Detached ADU size cap: 50% of primary dwelling floor area. ADUs per parcel: 1 maximum. Extra parking: 2 off-street spaces required.

Creating a second dwelling unit without an ADU permit violates Sioux Falls zoning code and can result in a stop-use order, fines up to $500/day, and a required reversal of the conversion. Renting an unpermitted converted garage as a separate dwelling also runs afoul of the city's Residential Rental Permit program (Title 96).

ADU Rules

Sioux Falls allows one accessory dwelling unit (ADU) per single-family lot under § 160.093 of the city zoning code. One of the two units must be owner-occupied, and a detached ADU is capped at 40% of the main structure's square footage.

Key details: Code Section: Sioux Falls Code § 160.093 (Accessory Uses). Units Allowed: 1 ADU per single-family lot. Owner Occupancy: Required for one of the two units. Max Size (Detached): 40% of main structure. Parking: Additional off-street spaces required per § 160.550.

ADUs constructed without a building permit or that fail to maintain owner occupancy may be cited under § 160.999 (zoning penalties) and the building code enforcement provisions of Title 50. Continuing violations are typically charged per day.

The Bottom Line

Sioux Falls's accessory structures rules are a mixed bag. Some areas are strict, others are relaxed, and the details matter. The best approach is to check the specific rule that applies to your situation rather than assuming Sioux Falls is broadly strict or permissive.

Keep in mind that Sioux Falls can amend these rules at any council meeting. For the most current version of any rule mentioned here, check the specific ordinance page, where we track updates as they happen.