A floating deck is the right answer in Colorado when your house can't take a ledger, or you want the deck at yard level. It's permit-exempt under 200 square feet, under 30 inches, and freestanding — no guardrail required — but still needs footings below the 30–36-inch frost line. A 200–300 square foot build runs $8,000–$16,000.
A floating deck — freestanding, low to the ground, not attached to the house — is one of the most underrated, and most misunderstood, projects we build. 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.
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 against the wall, and no load transferred into a structure that may not take it.
That last point is why floating decks are sometimes the right engineering answer, not the budget one. On older homes with a rim joist that can't safely carry a ledger, on brick or stucco walls, or on cantilevered floors that shouldn't carry a deck at all, a freestanding structure isn't a compromise — it's what a careful builder chooses on purpose, a call we make during design on plenty of older-home projects.
The permit math: the under-200 exemption
Building codes carve out an exemption most homeowners have never heard of. A deck is generally permit-exempt if it clears all three tests at once:
- Under 200 square feet — a 14×14 (196 sq ft) is about the biggest footprint that qualifies
- Under 30 inches above grade at every point
- Freestanding — not attached to the house, and not serving the home's required exit door
Miss any one and you're pulling a permit like any other deck. Hit all three and the paperwork can disappear — along with the railing: guardrails are only required above 30 inches, so a ground-hugging floating deck skips the 36-inch guardrail and its $30–90 per linear foot cost entirely. A few metro towns regulate lower structures too, so confirm local rules — the permit guide covers who requires what.
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, the metro sees 35–90 freeze-thaw cycles a year, 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 — typically 4 to 8 of them at $150–600 each, exactly as an attached deck gets. This is how we build nearly all of them. (Engineered ground screws driven below frost depth are the legitimate alternative on tight-access lots; blocks-on-dirt is not.)
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.
One low-deck detail that matters for composite: manufacturers require free airflow under the boards, so a floating deck framed tight to grade still gets ventilation clearance designed in.
Where floating decks shine
Under 30 inches. The permit exemption and skipped railing covered above are the floating deck's structural advantages turned into line-item savings.
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. A typical build lands 8–10 inches off grade: 2×6 or 2×8 joists plus an inch of decking.
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 (that's the $30–90 per linear foot you're not spending). 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 cost more than the flatland internet promises — but far less than rebuilding a heaved deck in five years.
Attached or floating: how we decide
The trade-offs side by side:
| Attached deck | Floating deck (under 30") | |
|---|---|---|
| Connection to house | Ledger — flashing and structural attachment required | None; no cutting into siding |
| Permit | Always | Exempt if under 200 sq ft, under 30", freestanding |
| Guardrail | Required above 30" grade ($30–90 per linear foot) | Usually skipped entirely |
| Footings | Below frost line, 30–36" | Same — frost doesn't care |
| Height | At door level | At yard level (typically 8–10" off grade) |
| Typical 200–300 sq ft cost | $12,000–$21,000 with railing and stairs | $8,000–$16,000 |
Beyond the table, 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.
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.
