An addition is the biggest remodel most owners take on. It is also the hardest to price from the internet, because so much of the cost is structure you never see when it is done.
So here is a real one: a second-story addition we are finishing this fall, what it cost, and where every dollar went.
The job
Three bedrooms, a family room, a full bath and closets, built over a new garage in Francis, in the Kamas Valley east of Park City.
Signed price
$323,903, in June 2026.
Change orders
About $42,000 approved as of October 2026, for a running total of about $366,000.
Permit
$5,367 to Francis City, billed on its own invoice.
Plans
A 35-sheet plan set from a residential designer, dated December 2025.
Timeline
Signed in June 2026. Final walkthrough set for early November 2026.
Where the money went
This is the signed price, grouped by trade. Notice how much of it is structure and supervision, and how little is cabinets and fixtures. These were bedrooms, not a kitchen.
| Part of the job | Share of the price |
|---|---|
| Framing, trusses and steel | 20% |
| Project management and daily supervision | 18% |
| Drywall and paint | 11% |
| Excavation and concrete | 10% |
| Trim and interior doors | 8% |
| Demolition and dumpsters | 7% |
| Electrical, plumbing and heating | 5% |
| Windows, exterior doors and siding | 4% |
| Flooring | 4% |
| Site support and supplies | 3% |
| Roofing and gutters | 3% |
| Garage doors | 2% |
| Cabinets, counters and hardware | 2% |
| Insulation | 2% |
Shares of the signed price, rounded. The building permit was billed separately.
What drives the cost of an addition
- Structure. Digging, footings, walls, the slab, framing, trusses and the roof were almost a third of this job.
- Tying into the old house. Demolition, roof tie-ins and matching what is already there all cost money. On this job we matched the existing oak floors and the alder doors and trim.
- Supervision. An addition takes months, and someone has to run the site every day. That is a real line, not overhead hiding somewhere.
- Finish level. On a bedroom addition, cabinets and fixtures are a small slice. Add a kitchen or a primary bath and that slice grows fast.
- Permits and plans. Plan on a full set of drawings and a building permit, billed as they come in.
Rules that add cost around Park City
- Wildfire rules. Park City's wildland urban interface code applies to every addition. The landscaping and home hardening plan is reviewed with the permit.
- Height and building pads. Park City limits height by zone, and many lots have a platted building pad. Our Deer Valley guide covers both.
- Snow. The engineer sizes the roof for your lot's snow load. A roof that sheds snow onto a neighbor's property needs a plan for it.
- Steep lots. Summit County requires a geotechnical report on lots with slopes of 15% or more.
- HOA review. Almost every HOA reviews additions. See our Promontory, The Colony and Deer Valley guides.
How to budget for an addition
- Start with the rooms you need, then let the designer and the builder price the structure before you fall in love with a layout.
- Ask what the price includes on the existing house: roof, siding, paint and floors where the new meets the old.
- Decide early who picks finishes, and set allowances you can live with.
- Keep money aside for change orders. Many owners add something once they see the space framed.
- Ask how the permit and plan fees are billed.
How we handle it
We price the structure, the tie-in to the existing house and the finishes together, so the number covers the whole addition. We list what is not included in plain words, and we run the job with a project manager and a site super every day it is open.
Common questions
How much does a home addition cost near Park City?+
Our second-story addition in Francis, with three bedrooms, a family room and a full bath over a new garage, was signed at $323,903 in June 2026. Approved change orders brought it to about $366,000 by October.
What is the most expensive part of an addition?+
The structure. On that job, framing was about 20% of the price and excavation and concrete about 10%. Project management and daily supervision were about 18%.
Does an addition need a permit?+
Yes: plans, a building permit and inspections. In Park City, every addition also falls under the city's wildland urban interface code, which reviews landscaping and fire hardening at permit.
How long does an addition take?+
On the Francis job, the plans were drawn in December 2025, the job was signed in June 2026, and the final walkthrough is set for early November 2026.
Will the addition match my house?+
It should. On the Francis job we matched the existing oak floors, the alder doors and trim, and the fascia.
Are permit fees included in the price?+
Not on that job. The Francis City building permit was $5,367 and was billed on its own invoice.
Where these numbers come from
The numbers come from Three Peak's signed price on a 2026 addition in Francis, Utah. Every addition is different, so your plans and your estimate set your real number. Park City and Summit County rules were checked in October 2026.
Next Step
Planning an addition?
Tell us what rooms you need and send any plans you have. We will tell you what drives the cost on your lot and what to budget.
Schedule a ConsultationOr call 435-214-1669