ADUs in Sandy Under the New Rules

Sandy adopted its detached ADU rules on September 15, 2026, and the city's own ADU web page has not caught up: it still says detached accessory apartments are not permitted. Before this change, Sandy allowed ADUs inside the home and small non-rental guesthouses, but not detached rentals. The new code changes that for larger lots, and it keeps a structure that is distinctly Sandy: every ADU is a licensed rental with a permit that ends when the owner sells or moves out.

Because the code is so new, we read it against the specific lot and confirm open points with Community Development before any design work.

Where the new opportunity is

Under the new land use tables, an ADU (attached or detached) is a special use in the R-1 zones, and in the R-2, RM and PUD zones for detached single-family developments only. Mobile home zones are excluded. The approval is an administrative Special Use Permit from Community Development plus a business license; there is no conditional use permit or Planning Commission hearing. Council members described the rules as a starting point, and staff suggested considering wider eligibility later, so they may change again.

ADU types in Sandy

• Attached ADU: a rental unit within the home, such as a basement apartment, or an addition. An addition must share a common wall at least 20 percent of its perimeter with the living area, not connect through a garage or breezeway, and match the house's style, with at least 20 percent of facades in a house material and 50 percent in its main color. See attached ADUs.
• Detached ADU: a separate building on a lot of 11,000 square feet or more. See detached ADUs.
• Converted accessory building: a legal shed, garage or workshop built before October 1, 2026 may be converted if it meets the section and building codes, without losing required parking.
• Extended living area: space for household members that is not rented. It is approved at building permit review, with no ADU permit.

Only one ADU may operate at a time, and only one detached self-contained living unit is allowed on a property.

Detached ADU size and height: three caps and two options

A detached ADU is limited to whichever of these is smallest:

1. 2,000 square feet of gross area;
2. a footprint of 75 percent of the house's footprint;
3. the accessory structure limit for the lot: on lots up to 14,999 square feet, 25 percent of the rear yard or 750 square feet, whichever is less, rising to 1,000, 1,500 and 2,000 square feet on larger lot bands.

On the smallest eligible lots, 11,000 to 14,999 square feet, the third cap means 750 square feet or 25 percent of the rear yard, whichever is less. That table covers the combined footprint of all accessory structures, so a lot with a detached garage may have less room than it seems; we confirm the count with Planning.

Height comes in two options. Option one: up to 15 feet, 10 feet from side and rear lines. Option two: up to 1.5 stories and 18 feet, no taller than the house, meeting the house's setbacks for the zone but never less than 10 feet. Either way the unit sits at least 6 feet from the house, in the side or rear yard behind the front plane of the home. Basements are allowed. Whether living space over a detached garage can fit within these caps is a question for Planning; see ADUs above a garage and ADU size and layout.

Lot and site considerations

Porches, decks, exterior stairs and balconies cannot sit in a required setback, though eaves may project up to 2 feet. Roof decks and second-story balconies are prohibited unless the unit meets the house's setbacks. No ADU may be built in a recorded easement, the unit needs a permanent foundation, its design must be consistent with the house, and exterior lighting must be dark-sky compliant. See ADU design.

Properties in the Sensitive Area Overlay, which covers slopes of 30 percent or more, floodplains, streams and natural hazard areas, need a stamped site, grading and drainage plan, and buildings must keep their distance from protected hillside areas.

Sandy's rules for owners and rentals

• Owner: an individual or family-trust trustor with at least 50 percent ownership, living in the house or the ADU. No LLC or corporate owners. Proof of residence is listed in the code; the city's older packet asks for different documents, so confirm the current list.
• Parking: the house's base requirement is a two-car garage plus two driveway spaces. A detached ADU adds 1 space if under 650 square feet, or 2 if 650 or larger. Displaced parking must be replaced, and on-street parking is for visitors. A proposed transit-area reduction was removed.
• Short-term rentals: prohibited in a detached ADU. An attached ADU with approvals for both uses may alternate between short-term and long-term rental, one at a time. See ADU short-term rental rules.
• Records: the approval is recorded with the Salt Lake County Recorder before occupancy. The business license renews each year, and yearly inspections may be required.

Utility considerations

Separate utility connections, meters, addresses and mailboxes are prohibited, though private meters behind the main meter inside the home may be allowed. Sandy's utility list names four sewer providers (Midvalley Improvement District, Sandy Suburban Improvement District, Cottonwood Sewer Improvement and South Valley Sewer District), so sewer requirements and fees depend on the address. Public Utilities must also approve before work starts, separate from the building permit. A home on septic must show the system works or connect to sewer. See ADU utility connections.

The Sandy ADU process

1. Feasibility: lot size, accessory footprint, height option, parking and sewer district.
2. Design and engineering, including a detached ADU parking plan and site plan.
3. Special Use Permit and business license application to Community Development, by appointment.
4. Building permit through the Sandy Cityworks portal and Public Utilities approval.
5. Construction, inspection, recording, then the license and permit.

See ADU permitting and our process.

Cost factors

The height option you choose, which setbacks it triggers, added parking, the sewer district's lateral and fee requirements, engineering, any sensitive-area or wildfire construction, and matching the house's design are the local drivers. City permit and license fees apply, and we confirm the current amounts for the fiscal year. The Utah ADU cost guide explains the rest.

With rules this new, a lot-specific answer is worth having before design. See What Your Property Can Support.

Questions from Sandy homeowners