Home Addition Cost in Tooele, Utah
Upterra Builders · March 23, 2026
When a family outgrows their house here, the choice is usually add on or move. With home prices where they are in Tooele County, adding on often wins. But an addition is the most involved thing you can build short of a new house, because you are pouring foundation, framing, roofing, and tying into an existing structure all at once. Here is what it really costs.
The Number: $250 to $500 Per Square Foot
A finished room addition in Tooele runs roughly $250 to $500 per square foot. That is a big spread, so here is what puts you at each end:
- $250 to $325 per sq ft: a simple bump-out or bedroom addition, standard finishes, no plumbing
- $325 to $425 per sq ft: a larger addition with a bathroom, or a family room with lots of windows
- $425 to $500+ per sq ft: a primary suite or kitchen expansion with high-end finishes, or a two-story addition
So a 400 square foot bedroom and bath addition typically lands between $120,000 and $170,000. A 200 square foot bump-out to enlarge a living room might run $55,000 to $75,000.
Why an Addition Costs More Per Foot Than a Remodel
People always ask why an addition costs more per square foot than finishing a basement, where the shell already exists. The answer is that with an addition you are paying for the whole shell from the dirt up:
- Foundation and footings. Excavation, forms, concrete, and in our cold Utah climate, footings dug below the frost line.
- Framing and roofing. A whole new roof section that has to tie cleanly into the existing roof so it never leaks.
- Exterior. New siding or brick, soffit, fascia, and windows that match the existing house.
- Tie-in work. Cutting into the existing house, matching floor heights, and extending HVAC, electrical, and sometimes plumbing.
A basement finish skips all of that, which is why it is roughly half the per-foot cost.
What Drives Your Price Up or Down
Plumbing
A bedroom addition with no water is far cheaper than a bathroom or kitchen addition. Running new supply and drain lines out to a new corner of the house adds real money.
Roof complexity
A simple shed roof off the back is cheap. Matching a complex hip or gable roofline so the addition looks original costs more in framing labor.
Single story versus two story
A second-story addition can actually be efficient per foot because you reuse the existing foundation, but it requires an engineer to confirm the existing structure can carry the load, and that adds cost and time.
Matching the existing house
On the older Old Tooele homes, matching original brick, trim, and window styles takes extra effort. On a newer Overlake or Stansbury Park home, materials are easy to source and match.
Permits, Engineering, and the County
Additions always require a building permit, and almost always a stamped structural plan from an engineer. Plan review and permit fees for an addition in Tooele County typically run $1,500 to $4,000 depending on size and value. Setbacks matter too, so before you fall in love with a plan, we confirm how close you can build to your property line.
Is It Worth It?
An addition rarely returns its full cost dollar for dollar at resale, but that is the wrong way to think about it. If moving to a bigger house means a new mortgage, agent fees, and leaving a neighborhood and schools you like, staying put and adding the space you actually need often makes more sense. We will give you a straight answer on whether your project pencils out before you commit.
Upterra Builders is owned by Danny and Trayson and builds additions across Tooele City, Stansbury Park, Grantsville, Erda, and Stockton. Licensed and insured in Utah. Call or text (435) 248-0339.