Planning estimates · Herriman, Utah
Deck cost calculators for Herriman
Six tools, one for each part of the work. Every one of them asks the same question first, because in Herriman one measurement decides the permit, the fee, the inspections and whether you need a guard around the whole deck: how far is it down to the lowest grade around the perimeter.
Six tools, one for each part of the work
In Herriman, thirty inches decides four things at once
Most cities have a height at which a deck needs a permit, and a separate height at which the building code requires a guard rail. In Herriman they are the same number, and that makes one measurement worth more than any material decision on this site.
Herriman exempts a deck from permitting when it is:
“30″ or less measured from the walking surface of the deck to the lowest grade level around the perimeter”
— provided there is no new roof structure over it and it does not serve the required exit. At exactly the same 30 inches, IRC R312.1 requires a guard. So a deck that creeps over the line picks up the permit, the published fee, the drawings, the inspections and a guard around every open edge, in one step.
The part that catches people is the words lowest grade level around the perimeter. Not the grade at your back door. Herriman sits at about 5,000 feet against the Oquirrh foothills and a great many lots fall away from the house, so a deck that measures 28 inches at the wall can easily be 40 inches at the far corner. Forty is the number that counts.
| Measured to the lowest grade | Permit | Fee | Guard around the open edge |
|---|---|---|---|
| 30 inches or less, no roof over it, not the required exit | Not required | $0 | Not required by code — your choice |
| Over 30 inches | Required | $432.39 | Required: 36 in high, 4⅜ in infill, 200 lb load |
| Any height, with a roof or pergola over it | Required | $432.39 | Depends on height |
| Any height, serving the required exit | Required | $432.39 | Depends on height |
Nearly every house in Herriman went up after 1998
That is unusual, and it is useful. It means the city’s original builder decks are all roughly the same age, were built to roughly the same details, and are now reaching the end of the same twenty-odd year window at the same time. They also fail in the same four places, and three of the four are invisible from the top of the deck.
Utah is hard on a deck in both directions. Summer pulls moisture out of the lumber until boards cup, check and work their fasteners loose. Winter drives water into every joint and freezes it. A detail that was merely adequate in 2002 has had twenty of those cycles to prove it.
| What gets found | Why it happened | What it means now |
|---|---|---|
| Ledger nailed rather than bolted | Faster to build, and it holds fine until it does not | The deck is held to the house by fasteners loaded the wrong way. This is the failure that hurts people |
| No flashing behind the ledger | Invisible once the siding goes back | Twenty years of water into the rim joist. The wall repair is often larger than the deck repair |
| Hangers sized for the wrong lumber | The right shape, the wrong rating | Connections carrying less than the drawing assumed, usually found only when the boards come off |
| Footings that stopped above frost depth | A shallower hole is a quicker hole | Heave every spring. Nothing built on top of them stays level, so nothing above them can be repaired into holding still |
What these usually land at
The default answer in each calculator, for a 16 ft by 12 ft deck sitting 36 inches above the lowest grade — so, just over the line, with a permit and a guard. Change any answer and the number moves, which is the entire point of the tools.
| Calculator | Typical range | What that assumes |
|---|---|---|
| New deck | $16,000 – $20,300 | 192 sq ft of capped composite on a graded lot, metal guard, one stair flight, permit included |
| Deck repair | $1,500 – $1,900 | Loose boards and a wobbly section of guard on a deck built between 1998 and 2005 |
| Deck replacement | $13,500 – $17,100 | The same deck rebuilt down to the existing footings in composite |
| Composite deck | $15,500 – $19,600 | The same 192 sq ft in a mid-range capped composite, composite guard |
| Wood deck | $12,700 – $16,000 | The same deck in western red cedar with a wood guard and a semi-transparent stain |
| Deck railing | $4,000 – $5,000 | 40 linear ft of powder-coated metal replacing an old guard, plus one stair flight |
| Resurfacing that same deck | about $7,500 | New composite boards on a frame that has been checked and is sound — half the cost of rebuilding it |
Tell us what the deck needs to do
Send a couple of photos, rough dimensions, and the height down to the lowest corner. We do not quote over the phone, because a number given without seeing the site is not worth anything to either of us — but you will get a straight answer about the permit, the guard and the ground before anyone talks about boards.
About these calculators
Are these calculators free?
Yes, and there is nothing to sign up for. Nothing you enter is sent anywhere and nothing is stored. The numbers are worked out in your browser as you change the answers.
How accurate are they?
They are planning estimates, not quotes. They are built from Herriman’s own published permit rules and fee, from the 2021 IRC requirements the city has adopted, and from current Salt Lake Valley deck cost data. They cannot see your grade, your soil, what is behind your ledger or how the last deck was built, and those are the things a real price turns on.
Why does every calculator ask how high the deck is?
Because in Herriman that single measurement does more work than any other answer on the page. The city exempts a deck that is 30 inches or less from the walking surface to the lowest grade level around the perimeter, provided there is no new roof over it and it is not the required exit. At the same 30 inches, IRC R312.1 requires a guard. So crossing 30 inches adds the permit, the fee, the inspections and a guard around every open edge, all at once.
Is it measured from my back door?
No, and this is the mistake that costs people money. Herriman measures to the lowest grade level anywhere around the perimeter of the deck. On a lot that falls away toward the Oquirrh foothills, the grade at the far corner can be a foot or more below the grade at the door. A deck that is 28 inches at the house can easily be 40 inches at the corner, and 40 is the number that counts.
What is Herriman’s deck permit fee?
The city publishes $432.39 for a deck permit. These calculators use that figure exactly rather than estimating one. Where drawings have to show a stair or a roof structure, an allowance for those is added as a separate line so you can see it.
What snow load should a deck here be designed for?
Herriman does not publish a single number, because it varies with elevation across the city. The city directs designers to the Utah State University snow load website for the value at a specific address. The other design criteria the city does publish are a 30 inch frost depth to the bottom of the footing, seismic design category D, and a 115 mph ultimate design wind speed at exposure C.
Do these calculators cover a permit for me?
No. They price the fee so it is in your budget, but the application, the drawings and the inspections are part of the job itself. Herriman’s Building Division is on 801-446-5327 and building@herriman.gov, and it is worth one call before you design around a height.
Why does the number come out as a range?
Because a single figure would be false precision. Two decks the same size on the same street can differ by thousands depending on the grade, the soil, what is behind the ledger and how much guard and stair is involved. The range is the honest answer at this stage. A firm number comes from somebody standing on the site with a tape.