Midvale Utah ADU Guide: How to Know If Your Lot Qualifies, What It Costs, and What to Do Next

Can You Build an ADU in Midvale, Utah?

The short answer: very likely yes, if your property checks a few boxes.

Midvale's municipal code expressly addresses both Internal Accessory Dwelling Units (IADUs) — think basement apartments, converted rooms, or additions within your existing home — and External Accessory Dwelling Units (EADUs) — detached backyard cottages, above-garage units, and standalone structures. The city's code includes ADU provisions in multiple residential zone sections, but Midvale still directs homeowners to verify their exact zoning before assuming an ADU is available on their specific parcel.

Here's what we know from the code: to qualify, your property needs to have one detached single-family dwelling, be larger than 6,000 square feet, and you need to live there. If those three things are true, you're probably looking at a viable path — and this guide will walk you through everything else you need to confirm.

Midvale ADU Rules: Internal vs. External Comparison

Midvale uses two terms you'll see throughout this guide: IADU (Internal Accessory Dwelling Unit) and EADU (External Accessory Dwelling Unit). Here's how they compare:

Sources: Midvale Municipal Code §17-7-1.2.1(D)–(E), §17-7-1.8, §17-7-4.2, §17-7-4.8; Utah Code §10-21-303; Utah Code §11-36a-202; Utah Code §57-8a. Note: EADU dimensional standards can vary between Midvale's different zones. The figures above reflect the most common residential zone standards, but your zone may differ — especially in the Junction at Midvale, Riverwalk, and TOD areas.

Which Is Better for You: Internal or External?

This depends less on the rules and more on your situation. Here's a quick framework:

Best Fit by Scenario

How to Check If Your Midvale Lot Likely Qualifies

This is the heart of the guide. Run through these steps and you'll know where you stand in about five minutes.

Which Midvale Properties Usually Have the Easiest ADU Path?

Not all qualifying lots are created equal. Here's what we typically see:

What Can Block or Delay an ADU in Midvale?

Let's be honest about the friction points. Knowing them upfront saves you time, money, and frustration.

What Does an ADU Cost in Midvale?

Let's talk real numbers. ADU costs vary based on what you're building, but here are the estimated ranges based on the Salt Lake County market:

These are estimates based on current Salt Lake County market conditions and may vary significantly based on site conditions, design complexity, finishes, and contractor. Always get a property-specific quote. See our Utah ADU cost guide for full methodology.

The Line Items That Change the Price Most

Why Internal ADUs Are Often the Smarter Financial Move

When you add up the savings — no foundation, no utility trenching, no separate site prep, exempt from impact fees — an internal ADU can cost 40–60% less than a comparable detached unit. For homeowners whose primary goal is rental income or family housing on a budget, the math almost always favors going internal.

That said, a well-built detached EADU typically commands higher rents and adds more to your property value. If you have the budget and the site conditions, the long-term return can be worth the higher upfront cost.

How Long Does a Midvale ADU Take From Start to Finish?

Here's a realistic timeline based on the Midvale permitting process and typical construction:

What Permits and Approvals Do You Need?

Midvale's building process involves two departments, and understanding the split saves confusion:

How the Process Works

1. 1
   Get a lot check. Before you pay for plans, confirm your lot works. A qualified builder can do this with a property visit.
2. 2
   Hire a designer and contractor. You'll need construction drawings for your permit application. Required submittals depend on the project and the city's review requirements.
3. 3
   Submit your permit application online. All Midvale building permit applications go through the city's online portal. Large files may need to be emailed to Building & Safety separately.
4. 4
   Wait for plan review. The city reviews your application for zoning compliance and code compliance. This typically takes 2–6 weeks. If corrections are needed, you'll get comments to address before approval.
5. 5
   Receive your permit and begin construction. Once the permit is issued and fees are paid, you're authorized to build.
6. 6
   Schedule and pass inspections. Key milestones are scheduled online in advance. Inspections are available Monday through Thursday.
7. 7
   Get your certificate of occupancy. Before the city issues the CO, you must record a notice against your property title with the Salt Lake County Recorder (the owner-occupancy disclosure). Once that's recorded and the final inspection passes, you're cleared to occupy or rent the unit.
8. 8
   If you're renting: get a business license. Midvale requires a Residential Landlord license for rental properties. The Good Landlord Program requires your unit to be free of administrative, building, zoning, and fire code violations.

Sources: Midvale Building & Safety; Midvale Municipal Code §17-7-1.2.1(D)(8), (E)(10); Midvale Business Licensing

Can You Rent Out a Midvale ADU?

Yes — with rules.

Do You Need a Business License to Rent Your ADU?

Yes. Midvale requires all rental properties to have a valid business license. You'll need to complete the city's Residential Landlord Application. The Good Landlord Program sets standards for rental properties, including the requirement that units be free of building, zoning, and fire code violations. This matters because it means your ADU needs to be properly permitted and inspected before you can legally rent it. Cutting corners on permits doesn't just risk fines — it prevents you from getting the business license you need to operate as a landlord.

What About Utility Costs When You're Renting?

Since Midvale prohibits separate utility meters for ADUs, you'll share utility bills with your tenant. Most landlords handle this one of three ways:

1. 1.
   Include utilities in the rent (simplest — just factor the cost into your rental price)
2. 2.
   Add a flat monthly utility fee (estimate based on historical usage)
3. 3.
   Split based on square footage (fair, but requires more tracking)

Including utilities in the rent is the most common approach and what we typically recommend. It simplifies your life and your tenant's.

Midvale ADU Design Standards: What to Know Before You Design

Understanding the physical constraints upfront prevents expensive redesigns later.

External ADU (EADU) Standards

Midvale's EADU development standards are zone-specific. Here's what the code commonly specifies in the standard residential zones (SF-1, SF-2, RM-12, RM-25):

The Cumulative Building Area Rule (This Catches People Off Guard)

The EADU building area cap isn't just for your ADU — it typically includes every accessory structure on the lot. That means your shed, your detached workshop, your greenhouse, and your EADU all count toward one shared maximum. If you have a 400 sq ft shed and you're on a standard 7,000 sq ft lot, your math looks like this: 13% of 7,000 = 910 sq ft total, minus the 400 sq ft shed = 510 sq ft remaining for your EADU.

Building Area by Lot Size (Common 900 sq ft / 13% Standard)

Internal ADU (IADU) Design Standards

Internal ADUs have far fewer physical constraints:

• • Size limit: Utah state law (§10-21-303) specifically prohibits municipalities from restricting the size of an IADU in relation to the primary dwelling. This is one of the strongest protections in the statute.
• • Appearance: The IADU should not change the exterior appearance of the primary dwelling — it should still look like a single-family home from the street.
• • Building code: Must meet all applicable building, plumbing, electrical, mechanical, fire, and health codes — including fire separation from the primary dwelling, egress windows in bedrooms, and proper ventilation.
• • Additions: If your IADU involves adding on to the existing building, the addition must comply with the development standards for your zone (setbacks, height, etc.).

Types of ADUs You Can Build in Midvale

Let's translate the legal categories into real-world options:

Utilities, Parking, and Addresses: The "No" List

What Happens When You Sell a Home with an ADU?

Midvale requires homeowners to record a notice against the property title before the certificate of occupancy is issued. This notice is a public disclosure that an ADU exists and that owner-occupancy rules apply.

Can the ADU be sold separately? No. An ADU cannot be sold or subdivided as a separate lot. It stays attached to the primary property permanently.

What About HOAs, CC&Rs, and Edge Cases?

What Midvale Homeowners Wish They'd Known Before Building

We see the same lessons come up again and again:

Is Building an ADU in Midvale Worth It?

For most qualifying homeowners, the answer is yes — and the basic math isn't complicated. You're building on land you already own. Utah's Wasatch Front rental market continues to show strong demand. A well-built, permitted ADU adds real equity to your property while generating monthly income that can meaningfully offset your mortgage, fund retirement, or house a family member who needs it.

The exact return depends on your project type, total cost, rental rate, and how long you hold the property. Internal ADUs typically pay back faster because the upfront cost is lower. Detached builds take longer to recoup but tend to add more property value and command higher rents.

What Should You Do Next If You're Serious About a Midvale ADU?

If you've read this far, you have a better understanding of Midvale's ADU rules than most homeowners in the city. Here's how to turn that knowledge into action:

Midvale ADU FAQ

How We Built This Guide

This guide was compiled by our team using primary sources — not recycled from other websites or generic national content. We reviewed Midvale's municipal code, city planning and building department materials, ordinance documents, and cross-referenced Utah state statutes.

A note on code numbering: Utah recodified the internal ADU provision from §10-9a-530 to §10-21-303 in late 2025. If you see other articles citing the old section number, it's the same law. We use the current numbering throughout this guide. Last reviewed: March 2026.

Ready to Find Out What's Possible on Your Property?

You've done the research. You understand the rules, the costs, and the process. Now it's time to get a real answer for your specific lot.

We help Midvale homeowners move from "I think I want an ADU" to "here's exactly what I can build, what it will cost, and when it will be ready" — and we do the first step for free.