ADU rules in Lindon

Since Ord. 2026-16 (adopted and effective September 21, 2026), "Detached accessory dwelling units are permitted on any lot or parcel that is eleven thousand (11,000) square feet or larger and contains a single-family dwelling, if the single-family dwelling is a permitted use on the lot or parcel," which tracks Utah Code 10-21-304. The unit must still go with an owner-occupied single-family dwelling that was not approved as part of an R2 overlay project, and only one accessory dwelling unit is allowed per dwelling. The 6,000 sq ft lot floor and the Accessory Dwelling Unit Map exclusions now apply to internal units only, so detached units on qualifying lots in the AFPD, R3 and Planned Residential Development overlay areas are no longer excluded by the map. The code does not authorize detached units on lots under 11,000 sq ft (city staff described 11,000 sq ft as the new minimum lot size, down from 12,000), and a legally built accessory structure may be converted into a detached unit with a building permit.

Internal accessory dwelling units (within the footprint of the house) are allowed with an owner-occupied single-family dwelling not approved as part of an R2 overlay project, but "Internal accessory dwelling units are prohibited on lots or parcels six thousand (6,000) square feet or less and in the areas adopted on the Lindon City Accessory Dwelling Unit Map"; some mapped-area lots with final plat approval dated on or after October 1, 2021 may be allowed. A unit may also go in a new or existing garage or accessory building substantially attached to the house by a covered walkway, breezeway or porch within 18 feet of the house. The amended code ties the lot-size and map rules to internal units by name and states no separate lot rule for these substantially attached units, so confirm eligibility with the city. One accessory dwelling unit maximum per dwelling.

Detached units must also be at least 300 sq ft and contain no more than 3 bedrooms, and the detached cap counts livable floor area across both stories combined. The substantially attached cap applies to apartments in garages or accessory buildings connected by covered walkways, breezeways or porches within 18 feet of the house. All accessory dwelling units must also meet the lot coverage limits of §17.44.120 and the zone (40% of the lot in the R1-12 and R1-20 zones). Ord. 2026-16 left these size figures unchanged.

Since Ord. 2026-16 the ownership rule reads "one (1) of the dwellings shall be owner-occupied", so the owner may live in either the house or the accessory unit (the City Council adopted it to let, for example, a senior owner live in the unit and rent the house), although §17.46.100(2)(a) and (2)(b) still speak of an "owner-occupied primary single-family dwelling". An owner occupant is someone with 50% or more recorded ownership (or a qualifying family-trust trustor) living there as a primary residence; temporary absences up to 3 years (military, disability, job assignment, ecclesiastical service) do not break owner occupancy. Utah Code 10-21-304(4)(c) lets a city require the owner of a detached unit to reside in the house or the unit, and 10-21-303 lets cities condition internal-unit rentals on owner residence. A short-term rental of an accessory unit still requires the owner to live in the primary dwelling (§17.80.030(6)).

Ord. 2026-16 replaced the flat 2-stall rule for detached units with a size-based ratio that matches Utah Code 10-21-304(3)(b) and (c); the local text says "six hundred fifty (650) square feet or less" for one stall and "or more" for two, so a unit of exactly 650 sq ft falls under both. Garage or carport stalls used by the house do not count toward the unit's stalls (or vice versa) unless the garage holds more than 2 vehicles with an accessible route to the unit, and garage or carport spaces lost to an internal unit must be replaced. Internal-unit parking may not be in the front setback; for detached units at most 1 designated stall may sit in the front yard setback and tandem side-yard parking can qualify. Surfaces must be dustless and hard (asphalt, concrete, compacted gravel, masonry or pavers), with a walkway from the unit's entrance to its stalls.

Approval runs through an accessory dwelling unit building permit, with fees per the city fee schedule, and conversion of a legally built accessory structure needs only "approval of a building permit" and code compliance. The section describes no conditional use permit, hearing or discretionary review for accessory dwelling units (only R2 overlay projects are conditional uses under §17.46.010), consistent with Utah Code 10-21-304(3)(a), which bars a conditional use permit for a detached unit in a primarily residential zone. The city may record a notice under Utah Code 10-21-303 when a unit is approved.

The ADU section bars selling or subdividing the unit separately from the single-family dwelling, parcel or lot. Chapter 17.80 allows an accessory dwelling unit to operate as a short-term rental only when the primary dwelling is owner occupied, requires a business license under Title 5, and adds short-term rental parking on top of the dwelling's required parking. Ord. 2026-16 also defines an internal accessory dwelling unit as one created "For the purpose of offering a long-term rental of thirty (30) consecutive days or longer", which sits uneasily with the short-term rental allowance for internal units; ask the city before planning one. No minimum lease term for long-term rentals and no residential rental licensing chapter appear in the code.