Home Additions, Casitas & ADUs in Southern Utah

Most Common Addition in Southern Utah: The Casita

When a family outgrows a house but doesn't want to leave the neighborhood, an addition is usually the answer. In Southern Utah, the most common addition we build is the casita: a small attached or semi-attached unit with a bedroom, bathroom, kitchen, and living area. Some are for aging parents. Some are guest spaces. A growing number are built as short-term rentals.

We also build full whole-home additions, second-story additions, and garage and carport additions.

Casitas: What Most People Are Actually Asking For

A standard Southern Utah casita includes:

• One bedroom
• One full bathroom
• A small kitchen or kitchenette
• A modest living area

Casitas can be attached to the main house (sharing a wall and often plumbing) or built as a detached structure on the property. Detached casitas often have simpler permitting if they're far enough from the main house and meet local setback requirements.

We can build a casita that ties into your existing home's plumbing and drainage, or build one with its own service connections.

ADU Demand in Washington County

We're seeing meaningfully more demand for casitas built specifically as Accessory Dwelling Units, either for long-term rental income or short-term/Airbnb use. If that's the goal, design choices matter: a separate exterior entrance, a kitchen big enough to actually use, and a layout that holds up to guest traffic.

Timeline

Once permits are in hand and HVAC, electrical, and plumbing subs are signed onto the permit, a casita addition typically takes about sixteen weeks (four months) of build time. Permits themselves can take additional months depending on the county and how complete your plans are when you submit.

If you've done your homework, finalized plans, confirmed setbacks with the city, and have everything ready to go, the build moves quickly. If you're starting from a blank page, expect to spend the first few months in design and permitting before construction begins.

Price Drivers

The biggest drivers of cost on an addition aren't the open living areas. They're the bathrooms and kitchens. Square footage matters less than how many wet spaces are in the addition.

A simple bedroom addition without a bath can be significantly cheaper than a smaller casita with a full kitchen and bathroom.

Foundation Work

Every addition starts with a compaction test on the soil where the new foundation will sit. Depending on what the test shows, we may need to dig down two to three feet and replace native soil with engineered road base, compacted in lifts and re-tested before concrete goes in. Skipping this step is how additions end up cracking or settling unevenly a few years in.

Roof Tie-Ins

Matching a new roof to an existing one cleanly is one of the harder parts of an addition. Depending on roof style (tile, asphalt, metal), we peel back the existing material, frame new trusses, build an overbuild section, and re-roof the transition so it looks like part of the original home.

If the addition is more like a detached pergola or covered patio, we can also build it as a fully separate structure, which avoids some of the permitting complexity.

Permitting in Washington County (and Iron, Kane)

Permitting is mostly digital now across all three counties. The process is similar everywhere: submit plans and required engineering through the city or county portal, wait for review and revisions, get the permit, sign on the required subs (HVAC, electrical, plumbing), and start the build.

Plan for permitting to take months, not weeks. The faster you can get plans and engineering finalized, the sooner the clock starts.