We were called in to finish — and make safe — what someone else left standing on scaffolding.

How we work

From assessment to a finished staircase

A single accountable team carried the project through five phases — diagnosing the problem, engineering and proving the fix, securing authority approval, then fabricating and finishing to a luxury standard.

A written, signed structural opinion

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Five ways to make it stand on its own

Rather than jump to one answer, we set out the realistic reinforcement strategies, each with its structural logic and its impact on the architecture — so the design conversation could be had on engineering terms.

Option A — Lateral fixing to structural walls

Option A — Lateral fixing to structural walls

Rigid connections tie the stringers back to the reinforced-concrete walls, cutting the cantilever span and restraining torsion. Concealed behind cladding to suit the architecture.

Option B — Central / vertical support column

Option B — Central / vertical support column

One or more steel columns carry vertical load directly to the slab, all but eliminating cantilever action and global deflection. Clad or decorated to match the design intent.

Option C — Suspended rods from above

Option C — Suspended rods from above

Steel tension rods hung from a new structural beam transfer vertical and torsional load upward. Effective, but dependent on new primary steel overhead.

Option D — Reposition to engage a wall

Option D — Reposition to engage a wall

Shifting the helix to bear against a structural wall gives a direct, redundant load path without visible lateral ties — at the cost of moving the architectural set-out.

Option E — Tread stiffening + added stringer

Option E — Tread stiffening + added stringer

Welded triangular stiffeners under each tread and a second outer stringer raise local rigidity. A complementary measure, recommended alongside one of the primary schemes.

What the rescue actually involved

A single scope took the staircase from survey to a finished, certified installation — engineering, reinforcement, and the full architectural finish.

Commercial figures are intentionally omitted from this case study.

Explore the engineered assembly

From the survey we rebuild a precise 3D model of the remediated staircase — the central mast, radial arms, helical stringers, treads and balustrade line. Drag to orbit, scroll to zoom.

Proving it with finite-element analysis

The remediated design was verified in SOLIDWORKS Simulation against the Dubai Building Code, ASCE 7-16 and Eurocode 1 — five static studies plus a modal analysis, on grade S275JR steel. The full-assembly model identifies the worst-loaded flight; every result is checked against code allowables.

Governing live-load case — von Mises stress across all three flights. Peak 122 MPa on the middle flight.Factor-of-safety field on the governing flight — minimum 2.25 at a welded bracket.Deflected shape under full live load (scaled). Peak movement 1.82 mm.Dead-load-only state of the complete assembly — lightly stressed, FoS 6.39.Local displacement at a concentrated 3 kN foot patch.Central Ø610 mast — stress under the 196.5 kN support reaction.

Every check passes with margin. The lowest factor of safety — 2.25 at a single welded bracket on the middle flight — sits above the residential threshold of 2.0, and the first natural frequency of 10.08 Hz is comfortably clear of the footfall range, so the finished stair feels firm underfoot rather than springy.

Verification report · p1Verification report · p2Verification report · p3Verification report · p4

Reading the code the way a reviewer will

A staircase passes authority review only if it is assessed clause-by-clause against the right code. Below is the actual reasoning CAworks set out against the Dubai Building Code 2021, Part K (Villas) — shown next to the real regulation pages it relies on.

The train of thought

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1 · Classify the stair correctly. This is a helical / curved stair, assessed under clause K.5.5.2.8 (spiral & curved stairs and winders). Because its tread band sits well away from the centre, we tested it against both the spiral and the curved thresholds — and it satisfies both, so the classification debate never changes the outcome.

2 · Confirm it is even permitted. K.5.5.2.1 expressly allows spiral, winder and open stairs in villas for everything except basement egress. This stair serves no basement, so no fire-rated enclosure is imposed by Part K.

3 · Separate requirements from recommendations. Intermediate landings (K.5.5.2.4) are a recommendation for villa flights over 4 m — not a requirement; the 3,660 mm between-landings limit belongs to Part B / the Fire & Life Safety Code and does not apply to villa stairs; the "spiral not recommended as a main stair" line is advisory, not a prohibition. Knowing which is which is what keeps a submission moving.

4 · Report the one genuine conflict honestly. Clause h) wants the outer handrail on the descending user's right; this helix turns the other way, placing the outer edge on the left. Handing is fixed by the direction of the spiral — it can only be "corrected" by mirroring the whole stair, which the architecture won't allow. So we record it as non-compliant as designed and propose a documented mitigation rather than hiding it.

• ✓
  10 checks — compliant as designed
• ~
  3 checks — standard verifications closed at shop-drawing stage (handrail geometry, guardrail heights & gaps, tread traction)
• !
  1 check — stair handing K.5.5.2.8 h): non-compliant as designed, with an engineering-judgment mitigation (continuous handrails both sides + generous tread depth, riser height, width and guarding) put to the authority at design-NOC stage

The regulations themselves

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The assessment reproduces every clause it relies on. These are the actual Dubai Building Code pages behind the matrix above.

Part K — circulation & landingsPart K — risers & treadsPart K — headroom & handrailPart K — spiral / curved stairs (incl. handing)Part K — curved-stair tread figurePart K — guardrailsPart K — landings (floor-to-floor)Tread band — model plan section

The compliance assessment

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Issued for the project's Consultant of Record to counter-sign and submit — a clause-by-clause matrix, the recommendation-vs-requirement reasoning, and the handing mitigation, all in one document.

Compliance report · p1Compliance report · p2Compliance report · p3Compliance report · p4Compliance report · p5

↓ Download the compliance assessment (PDF)

Why the approval has to be right — and on time

In Dubai, structural and life-safety documentation for a villa staircase is submitted through the project's Consultant of Record for authority review and a design No-Objection Certificate (NOC) before fabrication is released — and a completion certificate is needed at the end. Getting it wrong, or letting it slip, has real consequences.

A fabrication-ready drawing pack

The engineering resolves into a complete general-arrangement and detail set — plan, elevations, sections A–H, every connection detail, and a 3D isometric set — issued together with the calculations, compliance assessment and glass specification.

GA · plan, elevations, sections & connection details3D isometric set — remediated assembly with central mast

Rebuilding the steel, properly this time

Curved stringer segment under the workshop gantryWelding the stringer assembly in controlled conditionsStringer-to-tread connection detailMulti-segment hoisting for trial assembly

How the curved balustrade is made

Curving — slumped over a mould in the bending furnace Toughening — rapid air-quench locks in surface compression Laminating — two curved panes bonded with a structural interlayer

Illustrative of the curved-glass toughening and lamination process.

The balustrade is 17.5 mm curved laminated toughened glass — among the most demanding products in architectural glass. It is made in four stages:

1. Cut & shape. Flat float glass is cut to size and the edges are ground and polished — done before any heat treatment, because toughened glass can never be re-cut.
2. Curve. Each sheet is heated in a bending furnace until it softens and slumps onto a curved mould machined to the exact radius — here close to R980 — so the curvature is built into the glass itself.
3. Toughen. The curved pane is rapidly air-quenched (tempered), locking the surface into compression. It becomes several times stronger and, if ever broken, crumbles into small blunt fragments instead of shards.
4. Laminate. Two curved toughened panes are bonded with a structural interlayer, so the balustrade stays intact and in place even if a pane is damaged.

Curved laminated glass balustrade In-channel glass fixing detail

Helical & curved staircases by CAworks

A representative selection of CAworks helical and curved staircase work — from bare structural steel in the workshop to finished oak and curved-glass installations. These are separate projects shown to illustrate capability, not all the staircase in this case study.

Curved frameless glass balustrade with timber handrail Bronze-tinted curved glass balustrade, LED-lit Oak-clad helical flight, from above Bare steel helical structure during fabrication Helical steel stringer and balustrade posts Curved stringer fabricated in the workshop Primed curved steel before cladding Finished curved staircase, bronze glass balustrade

CAworks · Designer Glass & Structural Staircases

Inspect. Engineer. Fabricate. Finish.

One team accountable for the structure and the finish — from a propped, unsafe staircase to a certified, beautiful one.