Loft Garage ADUs in Salt Lake City: Rental Income & ROI Guide

Loft garage ADUs in Salt Lake City are two-story garages with a habitable loft or apartment above, allowed up to 24 feet tall for pitched roofs.
They generate rental income (typically $1,200–$1,600/month) but require larger setbacks from property lines as height increases.

What’s Changed with ADU Rules in Salt Lake City

The rules for building ADUs have changed a lot across the Wasatch Front. Thanks to local legislative updates and Utah’s Senate Bill 284, backyard over-garage apartments and detached garages with loft ADUs have moved from being heavily restricted exceptions to highly sought-after property investments.

But to make a two-story or lofted structure worthwhile, you need to navigate strict municipal design rules. The most important things to understand are:

• garage ADU height limits in Salt Lake City, and
• how setbacks from property lines slide as your building gets taller.

Below is a clear breakdown of how these rules work and how to use them to maximize your return.

The Baseline: The 17-Foot Rule

When you design a detached garage with a loft or apartment above, height is the key number for getting approval.

Salt Lake City sets a baseline maximum height of 17 feet for standard single-story detached accessory buildings. If your structure stays at or below 17 feet, you only need a 3-foot setback from your side and rear property lines.

What this means for your yard:
On most lots, a 17-foot structure is perfect for a standard multi-car garage with a basic storage attic. But it’s not tall enough to give you comfortable, legally habitable living space on a second level.

The Setback Trade-Off: Building Up to 24 Feet

To make a loft garage ADU practical, you usually want a pitched roof that reaches between 20 and 24 feet in height. This extra height gives you:

• standard 8-foot residential ceilings,
• room for framing, subfloors, and overhead mechanical systems.

Salt Lake City zoning allows detached ADUs up to 24 feet for pitched roofs (or 20 feet for flat roofs).

What this means for your yard:
If you build a full-height, 24-foot loft garage, you need a 10-foot setback from your neighbor’s fence lines instead of the standard 3 feet. That pushes the building closer to your main house and uses more of your backyard.

On narrow, historic urban lots—like those in Sugar House, Liberty Wells, or the Avenues—losing 7 extra feet of yard space on both the back and side can determine the entire layout of your project.

Maximizing ROI Within Your Parcel Boundaries

Because height limits and property lines interact directly, balancing these trade-offs is critical for getting a strong return on your investment.

1. Pre-Approved City Footprints

Salt Lake City offers a library of pre-approved standard ADU plan concepts. These plans can speed up permitting and streamline the architectural review process.

However, they still need to be placed carefully on your parcel map so your height-to-setback ratio matches your exact property lines.

2. The “Shell Only” Strategy

If you want to manage upfront costs, a smart approach is to:

• build a tall, multi-car garage,
• frame the exterior shell of the upper loft room, and
• leave the interior unfinished.

This secures your building envelope under current zoning rules while letting you finish the electrical, plumbing, and drywall later as your budget grows.

3. Lot Coverage Limits

In your rear yard, all accessory structures (including your new detached garage, patios, and sheds) cannot cover more than 50% of the space between the back wall of your home and your rear property line.