A floating deck — freestanding, low to the ground, not attached to the house — is one of the most underrated projects we build. It's also one of the most misunderstood, because the internet is full of flatland advice about setting one on concrete blocks and calling it a weekend project. At Colorado altitude, with our frost cycle, the rules are different. Here's the honest picture.
What "floating" actually means
A floating deck carries its own weight on its own supports instead of borrowing the house's structure through a ledger board. No ledger means no cutting into siding, no flashing detail against the wall, and no transferring load into a structure that may not be built to take it.
That last point is why floating decks are sometimes the right engineering answer, not the budget one. On older homes where the rim joist can't safely carry a ledger, on brick and stucco walls where attachment gets complicated, and on cantilevered floors that should never carry a deck at all, a freestanding structure isn't a compromise — it's what a careful builder chooses on purpose. It's a call we make during design on plenty of older-home projects.
The Colorado catch: frost doesn't care that your deck is small
The national DIY advice — set the frame on deck blocks resting on grade — works in climates where the ground doesn't move. Colorado's ground moves. Front Range frost depth runs 30–36 inches, and soil that freezes lifts whatever sits on it, unevenly, every winter. A block-supported deck here turns into a gentle wave within a few seasons: doors stop lining up with steps, boards pop, railings rack out of square.
Two legitimate ways to build it here:
Footings below frost line, even for a low deck. Proper concrete footings with post bases, exactly as an attached deck gets. The deck floats structurally — it just doesn't float seasonally. This is how we build nearly all of them.
A genuinely ground-level platform over a stable base. Where the deck sits inches off grade — over an existing slab, for instance — a sleeper system on the concrete works because the slab has already done its settling. Our guide to building a deck over a concrete patio covers that version in detail.
What we won't do is blocks-on-dirt. It's cheaper for exactly as long as it takes the first winter to find it.
Where floating decks shine
Under 30 inches. Most Front Range jurisdictions draw a permit-and-guardrail line at 30 inches of height. A ground-hugging floating deck often lands under it, which can simplify the paperwork and skip the railing requirement entirely — more view, less cost. We still confirm the rules for your jurisdiction; several metro towns permit lower structures too.
The yard-level outdoor room. A low platform floating in the yard — connected to the house by a path or a step, wrapped by planting — reads more like a landscape feature than a structure. It's the deck for fire-pit conversation pits, hot-yoga mornings, and shade-sail summers.
Around trees and over problem ground. Freestanding framing can step around roots and float over ground too uneven or root-bound to pour a patio on — often the only good answer on Denver's mature-tree lots.
Detached structures. Pergola platforms, outdoor kitchen islands, spa surrounds away from the house — all floating decks by definition.
What a floating deck costs
The surface math is the same as any deck — capped composite runs $40–$70 per square foot installed in the metro — but three things pull ground-level projects toward the friendlier end: no tall posts, no stairs to speak of, and often no railing. A 200–300 square foot floating deck typically lands in the $8,000–$16,000 range built properly, footings included. The cost calculator will give you a number for your size in thirty seconds.
One honest caveat: footings below frost line mean a floating deck here costs more than the flatland internet says it should. That delta is the price of a deck that's still flat in five years, and it's much smaller than the cost of rebuilding a heaved one.
Attached or floating: how we decide
It comes down to three questions we work through on the site walk: Can the house safely take a ledger? Does the design want the deck at door height or at yard height? And does the 30-inch line matter for your permit and railing picture? Sometimes the answer is a hybrid — an attached upper landing stepping down to a floating main platform, which is some of the best-living outdoor space we build.
Thinking about one? Send us a photo of the yard and we'll tell you which version your site actually wants — and our 10-minute deck safety inspection is worth a read if you're weighing replacing an old attached deck with something simpler.
