Hillside lots don't take rectangles well. You can put a single flat deck on a steeply-graded back yard, sure, and it'll be a deck. It'll also leave a third of your usable square footage marooned five steps above the rest of the yard, and another third hovering ten feet above grade with no way down except to walk all the way around the house. The fix is what we build most weeks of the year on the East Bench and the foothill suburbs: multi-level decks that step down the grade in a way that makes the whole yard usable.
This page is about that. The decks built on hillside lots in Suncrest, on the steep gravel-pit topography of Knudsen's Corner, in the Mount Olympus neighborhood where the foothills come right up to the back fence, and across the upper streets of the older affluent neighborhoods where the slope hits twelve to fifteen feet from house to property line. These lots want decks the catalog doesn't have.
Why multi-level is the right answer for graded lots
The argument against multi-level decks is mostly about cost. Each level adds framing complexity, structural connections, stair runs, code-required guardrails, and labor. A two-level deck typically costs 30 to 50 percent more than a single-level of the same total square footage. So it's a real consideration.
The argument for is what you get back. The deck becomes usable across its whole footprint instead of just the flat part. The upper level relates to the kitchen door or second-story bedroom slider; the lower level relates to grade-level entertaining (a fire pit, a pool, a lawn play area). Each level can serve a different function, where a single flat platform tries to do everything and does most things badly.
The other argument for is structural. A single deck floating ten feet above grade requires more bracing, deeper piers, and more visible framing than the same total square footage broken into two levels each closer to the grade beneath it. Multi-level decks distribute load across more piers spaced closer to actual contact points. The framing is lighter, the visual mass is lower, and the deck reads cleaner from the yard looking up at it.
The engineering that decides whether the deck holds up
Here's the part that separates a well-built elevated deck from one that gives the homeowner problems by year three.
Frost-line piers. Salt Lake County code requires footing depth 30 inches below finish grade for residential decks, which is the minimum frost line for the valley floor. At Suncrest's 6,400 feet, frost penetrates measurably deeper and we engineer pier depth accordingly. The cost difference between proper engineered piers and shortcut surface piers is small ($150 to $300 per pier). The cost difference in deck performance over 20 years is enormous. Surface-level piers on a hillside heave with every freeze-thaw cycle, and the deck warps with them.
Lateral bracing. Elevated decks need to handle wind load and (in Utah specifically) seismic load. The Wasatch Fault runs the length of the Salt Lake Valley, classifying the area as seismic design category D. Lateral bracing keeps the framing rigid against both wind and seismic forces. It's mostly invisible once the deck is finished, but it's not optional.
Ledger connection. The point where the deck attaches to the house is the most failure-prone connection on any elevated deck. It needs to be flashed properly to keep water out of the band joist, lagged or bolted with the right hardware spacing, and engineered for the load it'll see. Most catastrophic deck failures in the news are ledger failures. They're entirely preventable with the right specs.
Snow load and frost penetration. The unusually mild 2025–26 winter meant frost in the Salt Lake Valley penetrated to shallower depths than usual at lower elevations. Engineering for an elevated deck doesn't get to take that as the standard, though. The design has to handle the worst case the site will see across a 30-year deck life, not the warm winter we just had. The framing under your deck has to handle the snowpack of a heavy winter, not the snowpack of the mild one we're in now.
Don't skip the engineering to save money
Don't skip the engineering to save money on a hillside deck.
This is the most common shortcut we see and the most expensive one to fix. Homeowners get quotes from two contractors. One quotes engineered piers, lateral bracing, proper ledger flashing, and continuous load path framing. The other quotes the same surface decking and skimps on everything underneath. The second quote comes in 20 to 30 percent cheaper, and on paper it looks like the same deck.
It isn't the same deck. The second one fails earlier, costs more to repair than the savings, and on a hillside lot, can endanger the people on it. We see less hillside decks fail from inadequate framing than we see from poor level transitions, but when framing fails it's the more dangerous failure of the two.
The structural cost on a multi-level elevated deck is 25 to 35 percent of the total build. Cutting it in half to save 12 to 15 percent of total project cost is the worst trade in residential outdoor living. Pay for the engineering. Use it as the price filter against contractors who can't or won't quote it properly.
Frequently asked questions
How much more does a multi-level deck cost than a single-level?
For a hillside lot of equivalent total square footage, expect 30 to 50 percent more for multi-level construction. The added cost goes to additional framing, more piers, stair runs, additional guardrail (code-required around each elevated section), and the labor of building stepped construction. Most homeowners who price both options choose the multi-level once they see how much more usable the result is.
Do I need an engineer for the design?
For most multi-level decks in Salt Lake County, the design we produce is signed and stamped by a licensed structural engineer. Salt Lake City Building Services may require this for permits depending on the height, span, and complexity. For straightforward two-level decks on moderate grade, we sometimes design in-house against the prescriptive code tables. For complex hillside builds, particularly cantilevered sections or deck spans over 20 feet, engineered drawings are necessary.
What's the maximum height an elevated deck can go without becoming a different kind of project?
Anything above 30 inches off grade requires guardrails per Salt Lake County code. Above 10 feet off grade, the engineering complexity scales significantly (cantilevered designs especially). Above 24 feet, we're often into building permits with structural review and the project starts to look more like a balcony than a deck. A second-story doorway has to relate to the deck below, sometimes a cantilever is the right answer, sometimes a stair tower is.
Can a multi-level deck be built on a moderate (not steep) grade?
Yes, and it often makes sense to. Even a four-foot grade drop across a 30-foot back yard can be the difference between a single-level deck that requires three steps down to grade and a two-level deck that lets the upper level relate to the door and the lower level relate to the lawn. We do multi-level builds on moderate grade for the function, not the necessity.
Are you licensed and insured?
Yes. We're a licensed and insured custom deck builder serving Salt Lake County. General liability and worker's comp coverage are in place on every project, and we provide certificates of insurance on request before work begins.
Walk the grade with us
Multi-level decks have to be designed on-site, with the actual grade in front of you. Photos help, but a site visit is necessary. Send a couple of photos of the back yard along with a rough description of the grade drop and what you'd like the deck to do, and we schedule from there.
Call (801) 930-7243 or fill out the contact form.