Multi-Level / Elevated Deck

Multi-level or elevated deck construction is the build path for any residential deck where the surface is more than 30 inches above grade at any point — the threshold at which Washington State Residential Code requires structural engineering, code-spec guardrails, graspable handrails on every stair flight with more than three risers, and a Seattle DCI building permit pulled and inspected. Stepped landings between two or three levels are the most common multi-level configuration in the Seattle market because most local lots slope at least one direction and a single-level deck on a sloped lot wastes the lot's vertical structure. Engineered helical piles (the right answer on Seattle clay and hillside fill) or concrete piers below frost line carry the load down to bearing soil; LVL or laminated pressure-treated beams span between posts; pressure-treated 2x joists at 12 or 16-inch on center carry the deck boards; cedar, PT, composite, PVC, or tropical hardwood at the homeowner's selection finishes the surface. Five to eight working weeks of on-site construction plus 4 to 6 weeks for engineering review and Seattle DCI permit issuance before ground breaks. From $35,000 for a two-level 400 square-foot cedar or PT deck on engineered footings to $80,000 for a three-level 700+ square-foot composite or PVC build with cable rail across every level, integrated lighting on every stair flight, and a built-in bench at the lower level. Handis pulls the building permit as general contractor and coordinates the licensed Washington PE; both pass through as named line items, never as surprise margin. Any line-voltage lighting or hot-tub circuit routes to a licensed Washington L&I electrician.

Service

Process

How the Multi-Level / Elevated Deck Build Works

Six sequential phases from elevation survey through final Seattle DCI inspection — the actual working sequence we run on every multi-level deck more than 30 inches above grade, with structural engineering and the permit integrated into the timeline.

Step 1/6

Site Survey, Soil Probe, Engineering Trigger Confirmation

Estimate visit takes elevation readings at every footing position with a laser level, hand-augers a soil probe at every position (not just one or two — Seattle yards transition from native till to fill within a single lot), photographs the ledger zone, and confirms the deck triggers structural engineering and a Seattle DCI permit. We name the licensed Washington PE on the quote and the engineering fee as a pass-through line item, no markup.

Step 2/6

Structural Drawings Stamped + Permit Filed

The licensed Washington PE develops the structural drawings (footing schedule, beam sizing, post sizing, joist spacing, ledger detail, railing connection detail), stamps the drawings, and we file with Seattle DCI through the city plan-review portal. Plan-review queue is typically 3 to 5 weeks. We follow up weekly and update you on permit status. Once issued we are clear to break ground.

Step 3/6

Tear-Down (if rebuild), Helical Piles or Concrete Piers, 7-Day Cure

On a rebuild we demolish the existing deck and haul the debris. Helical piles install via the helical contractor on hillside or fill-soil lots — steel threading 9 to 14 feet down to engineered bearing capacity; no curing wait. Concrete piers hand-dug or auger-bored to 4 to 6 feet below frost line on stable native soil, poured with 3,000 PSI mix, 7-day cure before loading. Engineered post-base hardware (Simpson PB66 or equivalent) bolted to every footing.

Step 4/6

6x6 PT Posts on Engineered Hardware, LVL or Laminated PT Beams

Posts (6x6 PT minimum, larger per engineer on long spans) set on Simpson PB66 or equivalent engineered post-base hardware bolted to the footings — never set in concrete, which traps moisture against the post end-grain and rots from the inside out within 8 to 12 years. LVL or laminated pressure-treated beams span between posts with stamped column connections. Beam-to-post connection per the engineer's detail.

Step 5/6

Ledger with Continuous Flashing + PT 2x Joists + Stepped Landings

Ledger through-bolted with code-stamped LedgerLOK or FastenMaster bolts every 16 inches into the rim joist or foundation. Full continuous metal flashing tied into the house siding above; peel-and-stick membrane below. PT 2x10 joists at 16-inch on center for face-fastened lumber, 12-inch on center for hidden-fastener composite or PVC. Stepped landings frame at the spec'd height drops (12 to 18 inches between levels for a walkable transition). Stair stringers cut from PT 2x12 at 7-inch maximum riser and 11-inch minimum tread.

Step 6/6

Decking + Code-Compliant Guardrails + Graspable Handrails + Lighting + Final Inspection

Decking installs in the homeowner-selected material with its specific fastener and gap discipline. Guardrails at 36-inch minimum height on every elevated level — no spheres greater than 4 inches through balusters anywhere. Graspable handrails on every stair flight with more than three risers (1.25 to 2-inch diameter, returns at every end). Low-voltage lighting installed during framing; licensed electrician adds any new line-voltage circuit. Final Seattle DCI inspection scheduled by Handis as permit holder; we walk the deck with you and hand off the permit copy, engineer's drawings, and warranty paperwork.

Final pricing depends on number of levels, total square footage, elevation above grade (which drives footing depth and beam sizing), decking material selection (cedar and PT are the most affordable; tropical hardwood and PVC are the premium), railing system, and integrated lighting scope. Seattle DCI building permit fee and licensed Washington PE structural engineering pass through as named line items on the quote, not as surprise add-ons. The licensed Washington L&I electrician's portion (for any new line-voltage circuit) is also named line by line. Helical pile contractor fees pass through where helicals are specified by the engineer. Request a free in-home estimate for an accurate quote.

Send us back-yard photos with elevation context (the drop from house to back-yard line), the level count you are considering, and the decking material — we will quote the build including permit, engineering, and helical pile pass-through.

Call us

Trust

Why Seattle Homeowners Book Handis for Multi-Level Elevated Decks

The multi-level decks we are called to repair or demolish almost always fail at one of three connections — the ledger to the house (un-flashed, water tracked behind it and rotted the rim joist), the post to the footing (the original builder set the post in concrete and the end-grain rotted out from the inside), or the guardrail post to the joist (the original builder used four lag screws into a 2x10 joist and the post pulled out at year 8 under a side load). Handis treats every one of these as a non-negotiable line item — full continuous metal flashing tied into siding above and membrane below at every ledger, engineered post-base hardware (Simpson PB66 or equivalent) bolted to the footing on every post with no post-in-concrete shortcuts, and guardrail post connections per the engineer's stamped detail with the bolted-through-rim hardware (Simpson DTT2Z or equivalent tension tie) on every post. The visible deck surface is the cosmetic layer; the engineered connections to the house and to the ground are the deck.

Estimate

Tell us the lot context (sloped or flat, house elevation at the back wall, back-yard line elevation), the level count you are considering (two levels with a stepped landing is most common; three levels for a steeper lot), the total square footage you have in mind, the decking material (cedar, PT, composite, PVC, hardwood), the railing preference (PVC-and-aluminum, powder-coated aluminum panel, stainless cable, custom hardwood), and any add-ons you want priced (integrated lighting on every stair flight, built-in bench, planter, hot tub area). We send back a clear estimate with the permit, engineering, and helical pile pass-through named line by line and a project timeline including the 4 to 6-week permit and engineering review.

Reviews

Customer Reviews

Multi-level elevated deck construction reviews from real Seattle-area Handis customers.

1922 Capitol Hill craftsman, back yard sloped 4 feet from house to back property line. We wanted a two-level deck off the second-story kitchen door with a stepped landing down to a lower-level dining platform six steps below. Handis pulled the permit as general contractor, coordinated the licensed PE on the engineering (the engineering fee was named on the quote at $2,400 and came in at $2,200), and the soils engineer recommended helical piles because the back yard was on old fill. Eight working weeks on site after the permit issued; the deck has stood through three winters with zero settlement. The PVC fascia at the stepped transition between levels is the cleanest carpentry detail I have seen.

Patricia and James K., Two-Level Capitol Hill Hillside Build

Three-level composite build on a Queen Anne lot with serious vertical drop — 12 feet from upper deck to lower deck across three levels with stair flights between each. Engineering took 4 weeks before we broke ground, permit took another 3 weeks after the engineer stamped. The licensed PE actually came to the site for one inspection during framing to verify the cantilevered upper level was framed to his drawing. Nine working weeks. The cable rail across all three levels gives us the view we built for; the stair-riser lighting on every flight makes evening use safe for our older guests.

Andrew and Lara M., Three-Level Composite with Cantilevered Upper

We had two other contractors quote this build and one of them did not even mention the engineering or the permit as separate line items — just bid a single number for the whole project. Handis broke out the engineering fee ($2,400 pass-through), the permit fee ($1,100 pass-through), and the helical pile contractor cost ($6,800 across eight piles at $850 each) as transparent named lines on the quote. Total came in at $52,000 for a two-level 450 square-foot composite deck with cable rail and integrated lighting. No surprises in the middle. Worth shopping multiple bids just for the quoting transparency Handis delivered.

Stephanie and Mark T., Transparent Quoting on Two-Level Composite

1958 Magnolia rambler, the back yard had a 6-foot drop from the house pad to the lower-yard grade. We wanted the upper deck at house level, a 6-step stair flight, and a lower dining platform — three levels of vertical structure on a relatively small footprint. Handis ran 8 helical piles for the post footings (the geotechnical report recommended helicals because of the fill behind the original house pad), framed in PT 2x10 at 12-inch OC for the hidden-fastener PVC, and set the guardrails on bolted-through-rim Simpson DTT2Z tension ties per the engineer's detail. Seven working weeks. Permit inspection passed first try.

Lawrence and Jeanette M., Three-Level on Helical Piles

Tropical hardwood (Cumaru) on a two-level Madrona view deck, 480 square feet total. The engineer on the project was specific about the higher dead load on hardwood vs cedar and called for 2x10 at 12-inch OC and upsized two beams. Handis included the 1.5-week board acclimation in the schedule from the start. Eight working weeks of on-site build plus 5 weeks of permit and engineering before we broke ground. The lower level has a built-in Cumaru bench around the perimeter that doubles as the railing transition. Three years in and it looks identical to install day.

Camilla and Greg M., Cumaru Two-Level with Built-In Bench

FAQ

Frequently Asked Questions

Common questions about multi-level and elevated deck construction — pricing, permits, engineering, helical piles, ledger flashing, and what to expect on a Handis build.

How much does a multi-level or elevated deck cost in Seattle?

A two-level 400 square-foot cedar or PT deck on engineered concrete piers starts at $35,000. A two-level 450 square-foot composite deck with cable rail and integrated lighting runs about $45,000. A three-level 550 square-foot composite or PVC deck on hillside helical piles with stair lighting and a built-in bench runs about $58,000. A premium 650 square-foot multi-level build in PVC Reserve or tropical hardwood with a custom railing system and full lighting runs about $70,000. A top-end three-level 700+ square-foot build on hillside with premium decking and full cable rail runs $80,000. The Seattle DCI building permit (about $1,100), the licensed Washington PE structural engineering (about $2,400), and helical pile contractor fees (about $850 per pile where helicals are specified) all pass through as named line items on the quote. The licensed Washington L&I electrician's portion for any new line-voltage circuit is also named line by line.

When does a deck require structural engineering and a permit in Seattle?

Any residential deck where the surface is more than 30 inches above grade at any point triggers structural engineering and a Seattle DCI building permit under Washington State Residential Code. Any deck attached to the house in a way that affects the building envelope also triggers a permit (almost every attached deck does). Multi-level decks always trigger engineering because at least one level is by definition elevated. Decks on hillside or fill-soil lots trigger engineering regardless of elevation because the footings need to be sized to the soil bearing capacity. Decks under 30 inches above grade on stable native soil on a flat lot are exempt from the permit (typical floating ground-level deck). We confirm the trigger on the estimate visit before quoting.

Who pulls the permit and who pays the engineering fee?

Handis pulls the permit as general contractor under our contractor license. The licensed Washington PE we coordinate with develops the stamped structural drawings and submits them to Seattle DCI through the plan-review portal. We file the permit application the day we sign the contract and update you weekly on plan-review status. Both the permit fee (typically about $1,100 for an elevated multi-level deck, scaling with valuation) and the engineering fee (typically about $2,400 for a stamped drawing set on a multi-level build) pass through on the quote as named line items so you see exactly what each costs — no markup, no hidden margin. The fees are paid by the homeowner at contract signing; we forward the engineering payment to the PE and pay the DCI permit fee on filing.

How long does the permit and engineering review take?

Roughly 4 to 6 weeks from contract signing to permit issuance. The engineer typically takes 2 to 3 weeks to develop and stamp the structural drawings after we file the project scope and site survey with them. Seattle DCI plan-review queue is typically 3 to 5 weeks after we file with the city (the queue varies seasonally; spring and early summer are the longest because every deck build in the city is filing then). We follow up weekly during plan review and update you on status. If plan review comes back with comments (which happens on roughly a third of submissions for minor drawing clarifications), the engineer addresses the comments and we re-submit; that adds another 1 to 2 weeks typically. Construction starts the day after the permit issues.

What are helical piles and when are they used?

Helical piles are steel shafts with one or more helix-shaped plates welded to the lower end, threaded into the ground by a hydraulic machine to a depth where the pile achieves engineered bearing capacity (typically 9 to 14 feet on Seattle hillside or fill-soil lots, sometimes deeper). They are the right answer on any site where the bearing soil is below a layer of fill, soft surface clay, or hillside material that could move under load — common conditions on Seattle hillside lots and on properties where the back yard has been terraced or backfilled against retaining walls. Helical piles avoid the cost and risk of large concrete pier excavations on unstable sites; they install in a single day with no cure wait; the engineer calculates the spec per pile from the soil bearing capacity. We coordinate the helical contractor as part of the project and the per-pile fee passes through on the quote.

Why are posts not set in concrete?

A post set directly in poured concrete (still a common shortcut on builder-grade decks) traps moisture against the post end-grain and rots the post from the inside out within 8 to 12 years — invisible from the surface until the deck starts sinking or the railing starts moving. Handis sets every post on engineered post-base hardware (Simpson PB66, ABU66, or equivalent depending on the engineer's spec) bolted to the footing, with a small air gap between the post end and the concrete. The post drains, the end-grain stays dry, and the connection performs for the life of the deck. We do this on every multi-level build regardless of code minimum because the post-in-concrete failure mode is a well-documented PNW reality.

What does the ledger flashing actually look like?

The ledger is the horizontal beam bolted to the house that the deck joists hang from — the most common failure point in PNW residential decks because water tracking behind the ledger rots the rim joist or sheathing behind it out of sight. The correct assembly is three layers. First, the existing house siding above the ledger location gets cut back and a continuous Z-flashing (typically 26-gauge galvanized or aluminum) tucks behind the siding and laps down over the ledger top. Second, a peel-and-stick waterproof membrane (Vycor Deck Protector or equivalent) runs continuously below the ledger and onto the joist top, sealing every fastener penetration. Third, the ledger itself through-bolts with code-stamped LedgerLOK or FastenMaster bolts every 16 inches into solid rim joist or foundation. We photograph the assembly before the deck boards close it in; the photo goes in the permit file and your file.

What are the code-required railings and handrails?

Washington State Residential Code requires guardrails on any deck surface more than 30 inches above grade at a 36-inch minimum height. Balusters must be spaced so no sphere greater than 4 inches passes through anywhere on the deck level; at the bottom of stair balusters (the triangular opening between the bottom of the lowest baluster and the stair tread) the allowable sphere is 6 inches. Graspable handrails are required on every stair flight with more than three risers, at 1.25 to 2-inch diameter, with returns at every end (a horizontal return back to the wall or post so the handrail does not catch loose clothing or a backpack strap). The inspector at final inspection checks every one of these dimensions with a 4-inch sphere gauge. We frame to spec from day one; railings are not where we cut corners.

When is the best time of year to build a multi-level deck in Seattle?

On-site construction window is most efficient mid-May through late September because the ledger flashing and the concrete pier pours benefit from a dry week. Helical pile installations are weather-independent (the helical machine works in any weather) and concrete pier pours can happen in dry breaks year-round with a 7-day cure under cover. The permit and engineering review (4 to 6 weeks) is fully weather-independent and is often the right time to file in March or April so the permit is in hand for a May break-ground. Wet-season builds (October through April) are feasible — we tarp the frame between weather windows and sequence the ledger and the pours into the dry breaks — but the calendar time extends roughly 30 to 50 percent over a summer build. We give you a calendar-time forecast on the quote with the seasonal-multiplier honest.

Can you build a multi-level deck on a hillside lot?

Yes — this is one of the most common multi-level deck configurations in the Seattle market. The procedure adds a geotechnical engineering layer (a soils report from a licensed geotechnical engineer if the site is in a Seattle DCI Environmentally Critical Area or shows signs of past slope movement) on top of the structural engineering, and the footings are almost always helical piles rather than concrete piers (the steel threads through the soft hillside material and bears on engineered capacity below). The structural engineer sizes the helicals from the geotechnical report and the load schedule. Stepped landings between levels match the slope drop so the deck steps down with the hill. We have built dozens of hillside multi-level decks; the engineering discipline is the difference between a deck that stands for 30 years and one that moves the first wet winter.

Is the work guaranteed?

30-day workmanship guarantee covers any fastener that loosens, any picture-frame miter that opens, any railing post that moves, and any cosmetic finish. The structural framing (footings, beams, joists, ledger, posts, railing connections, stair stringers) carries our 2-year workmanship warranty on installation, separate from any decking-material warranty (the cellular PVC, capped composite, or tropical hardwood you selected has its own manufacturer or species warranty). The licensed Washington L&I electrician warrants their portion under their own license terms. The licensed Washington PE's stamp is on the drawings in the permit file as the engineering-quality guarantee — the engineer is responsible for the structural design and the stamp is their professional license backing it. All warranties in writing at project close along with the engineer's drawings and the Seattle DCI permit copy.

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