How Much Does a Home Addition Cost in Cache Valley?
Additions carry the highest fixed costs of anything we build, because you pay for foundation, framing, roof, and mechanical extension no matter how small the room is. That is why a 200 square foot addition rarely costs half of a 400 square foot addition.
These are ranges, not quotes — a real number comes from walking your house and writing the scope.
Most projects land between $150,000 – $250,000
Typical timeline: 3 – 6 months · Scope assumed: 300 – 800 sq ft addition
What Drives Cost Up
- A complicated roof tie-in — valleys, dormers, or a low-slope connection needing another roof system.
- Foundation conditions: a stepped footing on a sloped lot, expansive soil, or a required engineered design.
- Second-story additions, which need the existing structure verified and often reinforced, plus a new stair.
- Extending plumbing a long distance, or discovering the panel and HVAC cannot carry the new load.
- Matching an existing exterior that is discontinued, which can force re-siding a full elevation.
What Drives Cost Down
- A simple rectangle with a gable running the same direction as the existing roof.
- Building on the side of the house where the kitchen or a bath already is, so plumbing runs are short.
- Bumping out over an existing patio slab instead of pouring a full new foundation.
- Adding living space without plumbing — a family room or office is far cheaper per foot than a bedroom suite.
- Serving the new space with a mini-split rather than resizing and re-ducting the whole HVAC system.
Not sure where in that range you land?
The cost estimator asks four questions about your project and returns a live range for it.
What Each Level Actually Includes
Not marketing labels. These describe real scope differences.
A modest bump-out, roughly 200 to 350 square feet. No plumbing. Simple gable tie-in, standard finishes matching the existing house, mini-split or a short duct extension.
Where most land. 350 to 600 square feet with a bathroom or a wet bar, a real roof tie-in, new windows matched to the existing, upgraded insulation, and finishes consistent with the rest of the house.
600 to 800+ square feet, or a second-story addition. Primary suite with a full bath and walk-in closet, structural reinforcement, new stair, HVAC redesign, and higher-level millwork.
Questions We Get About Price
Broadly $280 to $420 per square foot in the valley right now, higher for second stories and anything with a bathroom. We are cautious about that number though — per-square-foot math badly misleads people on small additions, where fixed costs dominate.
Budget $5,000 to $12,500 for drawings, engineering, and permit fees on a typical addition, more for a second story. It is real money spent before a shovel moves, and it is the phase that keeps the build from going sideways.
Partially. Nationally, additions return roughly 50 to 65 percent at resale, and a bathroom or primary suite tends to do better than a bonus room. If resale is your main motivation, we will usually point you at a kitchen or bath instead and tell you why.
Setback or lot coverage issues, an HOA architectural review, floodplain mapping if the lot sits near a waterway, and engineering revisions. We check all of these during feasibility so they show up in week one instead of month three.
Want A Number For Your Actual House?
Ranges get you oriented. A walkthrough gets you a real figure. The first phone call is free; the on-site consultation is $500.