ADU Rules in South Jordan, Ut: What Changes on October 1, 2026

Two things are changing about accessory dwelling units in South Jordan. One is already settled state law. The other is a city ordinance that has not been voted on yet. It is worth keeping them straight, because most of what you will read online only covers the first one.

Status as of September 6, 2026.

What is already decided

Utah's Senate Bill 284, sponsored by Senator Lincoln Fillmore, was signed on March 17, 2026. Its accessory dwelling unit provisions take effect October 1, 2026.

From that date, cities like South Jordan must allow a detached accessory dwelling unit as a permitted use on lots of 11,000 square feet or larger that already have a single-family home, in zones where single-family housing is allowed.

"Permitted use" is the part that matters. Today, a detached unit can require a conditional use permit — a public hearing where the Planning Commission weighs it and neighbors can object. Under the new law, cities cannot require a conditional use permit in primarily residential zones. If your project meets the written standards, it gets approved. It stops being a debate and becomes a checklist.

The state also caps what cities can demand for parking: no more than two on-site spaces for a detached unit of 650 square feet or larger.

What South Jordan is proposing on top of that

Here is the part that is genuinely local news, and it is bigger than the state law.

South Jordan's Ordinance 2026-24 goes to the Planning Commission on Tuesday, September 8, 2026 at 6:30 p.m. at City Hall, 1600 W Towne Center Drive. City staff recommend approval. From the staff report:

"An ADU shall only be approved on a lot that is greater than six thousand (6,000) square feet."

The state requires 11,000. The city is proposing 6,000. That is not a small difference. An 11,000 square foot lot is roughly a quarter acre — a minority of South Jordan homes. Six thousand square feet takes in a very large share of the city's existing single-family neighborhoods.

The ordinance would also:

• Retire the word "guesthouse" from city code and replace it with "Detached Accessory Dwelling Unit," or DADU, to match state terminology
• Allow DADUs in any zone that permits single-family use
• Let accessory buildings stand up to five feet taller than the main house, capped at 25 feet
• Remove the pitched-roof requirement for accessory buildings
• Remove the conditional use permit option for accessory buildings

The rules that would still apply

You have to live there. The property must remain the owner's legal residence. This is not a rule for building a detached rental on a house you own elsewhere.

No short-term rentals. An ADU could not be rented for fewer than 30 consecutive days. That rules out Airbnb and Vrbo.

One more parking space. At least one off-street space in addition to what the main house already requires.

A privacy rule for upper-floor windows. Windows and doors placed more than four feet above ground would need a 20-foot setback from the property line, unless they sit seven feet or higher, or are angled roughly 80 degrees away from the boundary.

That last one did not come from nowhere. On July 28, the Planning Commission approved a detached garage and ADU on Gold Dust Drive by a 3–1 vote — the sole objection was second-story windows looking into neighbors' yards. The new window standard is the city's answer to exactly that fight.

The exception most people will miss

The proposed ordinance would permit DADUs in single-family zones except where a development agreement predates May 6, 2026.

Large master-planned areas of South Jordan are governed by development agreements. If you live in one, the new permission may not reach your lot even after the ordinance passes. Check your neighborhood's development agreement and your HOA's CC&Rs before you plan anything. A city ordinance does not override a private covenant you agreed to at closing.

What this means for you

If you own a home on a decent-sized lot. An option opened up that did not exist before, and the approval path is about to get much shorter. Whether it makes financial sense is a separate question — construction costs, utility connections and impact fees are real. But the zoning obstacle is coming down.

If you are buying. Lot size just became a value question, not only a lifestyle one. Two similar homes at a similar price are no longer equivalent if one sits on 6,500 square feet and the other on 5,400. You can compare lot sizes on current South Jordan listings.

If you are selling. "This lot may qualify for a detached ADU" is a genuine selling point in 2027 in a way it was not in 2025. Verify it before you put it in the remarks.

If you are investing. Read the owner-occupancy rule closely. This law is aimed at homeowners adding a unit, not at buying rental property. Also note the 30-day minimum, which closes the short-term rental angle entirely.

If you are house-hunting for family. Aging parents, an adult child, a caregiver — this is the use case the state legislature had in mind, and it is the one where the rules are most accommodating. If schools are part of that decision, see my guide to the best schools in South Jordan for families.

Common questions

Is this already the law in South Jordan?
Partly. The state requirement takes effect October 1, 2026 regardless. The city's own ordinance, including the 6,000 square foot minimum, is a proposal until the Planning Commission and then the City Council vote on it.

Do I still need a permit?
Yes. What changes is the type. A conditional use permit involves a public hearing and discretion. A permitted use is reviewed against written standards. You still need building permits, inspections and code compliance.

Can I rent it out on Airbnb?
No. The proposal sets a 30-day minimum rental term.

Can I build one and rent out the main house while I live elsewhere?
No. The owner has to keep the property as their legal residence.

How big can it be?
The state bars cities from setting a maximum size, though a city may cap the unit at the size of the primary home. Confirm the final city language once the ordinance is adopted.

What if my HOA says no?
Your HOA's rules are a private contract and are not overridden by city zoning. Check the CC&Rs first.

What happens next

Tuesday, September 8 — Planning Commission hears Ordinance 2026-24. Public meeting, City Hall, 6:30 p.m. Anyone can attend.

October 1 — The state law takes effect whether or not the city has finished its ordinance.

After that — the ordinance goes to the City Council for a final vote. Agendas are posted at the city's meeting portal, and I will update this post when it passes.

Sources

• Utah S.B. 284, enrolled copy (Utah State Legislature)
• South Jordan agendas, packets and minutes — September 8, 2026 Planning Commission packet and July 28, 2026 minutes

I sit through these meetings, which is the only reason I can tell you what is in the staff report before it becomes news. If you are wondering whether your specific lot qualifies, or what an ADU would do to your home's value, I am glad to look at it with you — no obligation, and I would rather tell you it is a bad idea for your property than not.

For more on the city itself, see my guide to living in South Jordan.

Sam Holman, Real Broker, LLC · 801-842-2225