Helical · Complete
Helical with curved laminated balustrade
Inner radius 900 mm, outer 2,500 mm. Low-iron laminated glass balustrade, brass PVD top rail.
Dubai · London · Serving Globally
Helical staircases,
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Helical staircases,
engineered to architecture.
CAworks designs, engineers, fabricates and installs fully bespoke helical staircases — end-to-end from our Al Quoz workshop in Dubai. Decades of UK experience in staircases and decorative glass, applied to the GCC's most demanding interiors.
About CAworks
From London townhouses to the Gulf's most demanding interiors.
CAworks is led by Ilja Andreevs and Evgeny Chernikov — partners with decades of combined experience delivering bespoke staircases and decorative architectural glass across Central London: Mayfair, Knightsbridge, Chelsea, the City. Helical stairs in townhouses, cantilevered floating spines in mews conversions, gold-leaf and verre églomisé glass features in heritage interiors.
In 2024 we brought the practice to Dubai, opening a full fabrication workshop in Al Quoz Industrial 4. The same engineering rigour, the same craft, now produced locally for the GCC and shipped globally.
Founder bios
Ilja Andreevs
Two decades of architectural metalwork and bespoke staircase fabrication in London. Led the production of curved-stringer and helical staircases for luxury residential and hospitality interiors across Mayfair and Belgravia. Specialises in 3D-bent laser-cut steel work and the engineering of cantilevered and floating staircase systems.
Evgeny Chernikov
Background in decorative architectural glass — laminated, bent, mesh-interlayered, gold-leaf and verre églomisé work for London high-end residential and hospitality. Oversees client engagement, design coordination, and the integration of glass balustrades with bespoke steel substructures.
Trusted by
Selected Projects
Selected projects delivered.
A condensed selection of helical, curved, floating and cantilevered staircases delivered in the UK and now in the UAE. Each one was bespoke — designed to architectural brief, structurally calculated, fabricated, and installed under our supervision.
Helical · Residential
Residential helical, double stringer
Double-stringer construction with bent-edge trapezoidal treads. Hand-shaped timber handrail on bent glass.
Helical · Crane Lift
Curved staircase, crane lift & install
Pre-assembled curved segments crane-lifted between floors. Rigging slings, scaffold ladders, full lift method statement.
Curved · Install
Curved stringer with oak treads
Bilateral curved plate stringer fabricated in workshop, oak treads laid on site over progress.
Floating · Cantilever
Cantilevered floating spine
Steel stringer concealed inside the wall pocket. Frameless glass balustrade on standoff bolts.
Zig-Zag · Folded Plate
Zig-zag steel staircase
Folded-plate stringer following the steps in a continuous zig-zag. Open-rise Scandinavian silhouette.
Additional project case studies available on request.
In motion
Watch the workshop.
A short film from the workshop floor — the heat, the sparks, the scale. Use the timeline to scrub through if you want to inspect anything in detail.
Anatomy of a helical staircase
Five decisions that define a helical staircase.
A helical staircase isn't one product — it's a system of decisions made in sequence, each one constraining the next. Below is how we structure that conversation with architects and clients.
01 · Geometry
Radius, rise and going
Inner and outer radius set the footprint and the visual character. Helical (a single sweeping arc) or variable-radius (egg/ribbon shape) — the choice cascades through every subsequent decision. Tread depth at the walk-line and total rise determine code compliance.
02 · Stringer
Double, mono or concealed
Double-stringer construction (the classic helical) uses inner and outer 3D-bent laser-cut steel beams shaped to the radius and paired to form U-channels for the treads. Mono-stringer (spine) and concealed (cantilever) options change the visual weight entirely.
03 · Treads
Closed riser or open
Trapezoidal steel treads — closed-riser for solid hospitality feel, open-riser for residential lightness. Top surface in hardwood (oak, walnut, ash), marble, sintered stone, or steel with patterned finish.
04 · Balustrade glass
Curved laminated, with decorative interlayer
Hot-bent laminated glass to the staircase radius — low-iron (crystal clear) when colour fidelity matters, or with a decorative interlayer: bronze metal mesh, brass woven mesh, fabric, gold-leaf, or printed film. 8+8 minimum for UAE residential code.
05 · Handrail & finish
Brass PVD, brushed stainless, or timber
Top-mounted profile on the glass, or side-mounted on the stringer. Brass PVD coating for warmth, mirror or brushed stainless for contemporary, hand-shaped timber for traditional interiors. All bends machined to the helix radius, not site-formed.
Staircase Typology
Nine structural concepts. One workshop.
Helical is the focus here, but the same workshop produces the full range of bespoke staircase typologies — each with its own structural logic, balustrade compatibility, and material palette.
★ Featured · Section G
Helical
A continuous sweep with no central post. Variable radius (egg, ribbon) or consistent radius. Pairs with curved laminated glass balustrade.
Variants
- Consistent radius — uniform circular sweep
- Variable radius — egg-shape, ribbon-like
- Double-stringer (U-channel) — most common
- Inner-stringer single-side cantilever
Section A
Floating / Cantilever
Steel stringer concealed inside a wall pocket. Treads appear to float. Frameless glass balustrade on standoff.
Variants
- Single-side cantilever
- Double-side cantilever (back-fixed)
- Full open run
Section B
Flying
Toughened laminated glass (21.5mm) as the sole stringer. Treads held by discrete stainless inserts. Used to open up small spaces.
Variants
- Glass-stringer with stainless tread inserts
- Engineering sign-off required
- Premium / bespoke only
Section C
Spine / Mono Stringer
A single central steel beam down the centre of the stair, step holders welded. Treads in wood, stone or glass.
Variants
- Open riser (no vertical between treads)
- Closed riser (solid riser panel)
- Standard box sections 40×80, 100×100, 150×150
- Bespoke custom-profiled beam
Section D
Double Stringer
Two parallel beams flanking the treads. Plate, Z-shape, U-channel, or box section. Familiar load-bearing logic.
Variants
- Plate stringer
- Z-shape stringer
- U-channel stringer
- Box / hollow stringer
Section E
Zig-Zag / Folded Plate
Scandinavian-inspired silhouette. The stringer follows the steps in a continuous zig-zag. Pyramid base optional for storage.
Variants
- Open-rise (Scandinavian look)
- Closed-rise (filled gaps)
- With pyramid base / base platform
Section F
Curved Stringer
Single or bilateral curved beam bent to radius. The straight-line cousin of helical, used where a full sweep isn't possible.
Variants
- Single curved beam (bent to radius)
- Bilateral curved plate stringer
- Pairs with curved (bent) glass balustrades
Section H
Spiral
Central post with outer stringer. Compact footprint — typical diameter 1.4 – 2.0 m. Glass, wood, or full carbon-steel treads.
Variants
- Centre-post sections Ø76 / Ø102 / Ø152 mm
- Outer stringer Ø114 / Ø168 mm
- Glass-tread, wood-tread, or full carbon-steel
Section I
C-Type / Industrial
Hot-rolled C-channel stringers, patterned plate or grid treads. Hot-dip galvanised + powder coated for utility and exterior use.
Variants
- C-channel 250×80×9 mm
- Patterned plate / chequer treads
- Grid / mesh treads
Materials Reference
The palette behind every staircase.
A working reference for the four primary materials we specify — structural steel and stainless, architectural glass and laminates, hardwoods, and marble finishes. What each material does best, and where it earns its place in Dubai's climate.
Part One · Steel
Carbon, mild, and stainless — and what they really mean
A staircase rarely uses a single steel. The visible handrail, the hidden stringer, the bracket bolted into the slab — each is sized to a different brief. Strength matters; so do corrosion resistance, weldability, finish, and what the local market can deliver on a sensible lead time. The figures below show how the grades we specify compare on the metrics that drive the choice.
Figure 01 · Load-bearing capacity
Yield strength by grade
How much load each grade carries before it deforms permanently — the foundation of every structural decision.
Mild steel
Carbon structural
Stainless · austenitic
Stainless · duplex
What this shows. The structural carbon grades (S275 → S460) and duplex stainless (2205) lead on raw strength. Austenitic 304 / 316 sit at the bottom — they are chosen for finish and corrosion behaviour, not load. Q235, the most common Chinese mild steel, slots neatly between the stainless pair and S275.
Figure 02 · Strength-to-weight
Load per kilogram
Specific strength — the metric that decides slim sections on long cantilevers.
What this shows. Density barely varies — every steel sits at 7,800–8,100 kg/m³. So the strength-to-weight order tracks yield strength almost exactly. S460 and 2205 Duplex tie at the top, letting us draw a slimmer stringer for the same load.
Figure 03 · Corrosion resistance
How each grade ages outdoors
Performance in humid, coastal, sun-exposed environments — the UAE brief.
What this shows. Carbon and mild grades will rust if exposed — they require paint, powder coat, or galvanising. Stainless 304 holds up indoors; 316 adds molybdenum and is the default for anything seeing salt air. 2205 Duplex is the structural-grade stainless when both load and finish are visible.
Figure 04 · Workshop behaviour
Weldability, cutting & finishing
How easily each grade is fabricated by the team on the floor — a quiet but decisive factor in cost and lead time.
What this shows. Carbon mild steels (Q235, S275, S355) weld cold with standard MIG and need no preheat — this is why they dominate hidden structure. S460 requires more care on thicker plates. Stainless welds beautifully but demands TIG, back-purge on critical seams, and dedicated grinding wheels to avoid contamination. Duplex is the most demanding of all.
Selection matrix
Where each grade earns its place
Our default specification by staircase element type.
| Grade | Family | Best applied to | UAE sourcing |
|---|---|---|---|
| S275 · Mild steel | Carbon | Hidden stringers, sub-frames, brackets, baseplates — all painted | Local · same-day |
| S355 | Carbon | Long-span stringers, cantilevered floating staircases | Local · same-day |
| Q235 · GB/T 700 | Carbon | Imported coil for fabricated components and non-structural sub-assemblies | Imported · planned |
| S460 HSLA | Carbon | Slim cantilevers and visually thin profiles under heavy load | Specialty order |
| 304 Stainless | Stainless | Indoor handrails, balustrade posts, fittings — dry environments only | Local · stocked |
| 316 Stainless | Stainless | Coastal handrails, exterior balustrades, pool surrounds, marine air | Local · stocked |
| 2205 Duplex | Stainless | Slim glass-rail posts where the steel must be both visible and structural | Specialty · premium |
The grade is never the question. The question is which element of the staircase, in which environment, finished in which way — and the steel answers itself.
CAworks workshop principle
Part Two · Glass
Architectural glass — clarity, safety & the role of low-iron
On a CAworks staircase glass is rarely just glass. It is the balustrade you brush against on the way up, the laminated stringer carrying the whole flight, sometimes the tread itself. The choice between clear and low-iron defines whether the colour beneath reads true. The choice between monolithic and laminated decides whether the panel is allowed inside a residence at all. The figures below show how each substrate, build-up, and treatment compares.
Figure 05 · Light transmission
Visible light through 6 mm glass
How much daylight each substrate lets through — and whether the panel adds its own colour to the room.
What this shows. Low-iron (ultra-white / crystal) transmits roughly 91% of visible light against 89% for standard clear — but the more important difference is colour. Standard clear has a faint green cast that becomes obvious on thick laminates and at exposed edges; low-iron is genuinely neutral. Specify low-iron whenever the panel is thicker than 12 mm, when edges are visible, or when sitting against pure white walls. Tinted variants are chosen for solar control and atmosphere, not transparency.
Figure 06 · Edge neutrality
Colour cast at the edge
How much green or grey the substrate adds to its own visible edges — critical where panels meet handrails or stand on standoffs.
What this shows. Standard clear edges read green; the thicker the panel, the more pronounced. Low-iron edges are nearly water-clear. For frameless cantilevered balustrades, where the top of the glass meets a polished handrail and the edge is fully visible, low-iron is effectively mandatory in luxury residential work.
Figure 07 · Opacity & privacy
How much each treatment hides
From fully transparent to fully obscure — the toolkit for managing sightlines between floors.
What this shows. Frosting and sand-blasting are read-through diffusers — silhouettes still register, ambient light still passes. Switchable PDLC moves between the two extremes at the press of a switch. Back-painting is the only finish that gives true full privacy with a flat colour face, which is why it dominates riser cladding on glass-tread staircases.
Figure 08 · Barrier load capacity
Horizontal line load on balustrades
Force per metre that each build-up resists at the top rail — the metric that determines whether a balustrade meets code for residential, commercial, or crowd-loaded use.
Monolithic toughened
Laminated (PVB)
Laminated (SGP) · premium
Code thresholds
Residential 0.74 kN/m
Commercial 1.5 kN/m
Crowd-loaded 3.0 kN/m
Indicative values for a 1100 mm balustrade height with typical mounting. Actual capacity is governed by panel height, span, fixing method (clamped, point-fixed, base-channel, frameless), edge condition, and interlayer specification — every project requires PE-stamped calculations on the exact build-up.
What this shows. The three dashed lines mark statutory thresholds: 0.74 kN/m for residential, 1.5 kN/m for commercial, 3.0 kN/m for crowd-loaded public balustrades. Plain monolithic glass is acceptable only when captured top-and-bottom in a frame. The moment the panel becomes free-standing — clamped, point-fixed, or cantilevered — UAE code requires laminated construction. 17.5 mm (8+8) is the residential standard; 21.5 mm (10+10) with SGP interlayer is the frameless cantilever default and clears commercial load comfortably.
Figure 09 · Walk-on load capacity
Distributed load on glass treads & floors
Vertical load per square metre that each build-up carries when used as a walking surface — and why walk-on glass is always triple-laminated, never double.
Double-laminated
Triple-laminated · walk-on
Code thresholds
Residential floor 1.5 kN/m²
Walk-on stair 4.0 kN/m²
Commercial 5.0 kN/m²
Indicative values for a typical staircase tread span (~900 mm) with edge support on two sides. Actual capacity is governed by tread length, support condition (two-, three-, or four-edge), interlayer (SGP versus PVB), thickness of each ply, and the sacrificial top layer specification — every walk-on panel requires PE-stamped calculations.
What this shows. Walk-on glass is always laminated with at least three plies — never two. The reason is redundancy: if the lowest ply fractures under impact, two intact plies remain to bear the load until replacement. A double-laminated panel that loses one ply has only one left — unsafe. The sacrificial top ply takes scratches and stiletto strikes, can be replaced without dismantling the structure, and is typically frit-printed or sand-blasted to provide grip. 8+8+8 is the residential staircase default; 10+10+10 or 12+12+12 for longer spans and commercial use.
Selection matrix
Build-up by application
The thicknesses and lamination patterns we specify for each part of a staircase.
| Application | Build-up | Processing | Notes |
|---|---|---|---|
| Infill panel · framed | 10 mm monolithic | Toughened | Captured top and bottom — single panel is sufficient |
| Balustrade · post-fixed | 12 mm monolithic | Toughened · HST | Heat-soak test mandatory above ground level |
| Balustrade · clamped | 8+8 laminated | Toughened lam | UAE-compliant standard — most common residential build-up |
| Frameless cantilever | 21.5 mm (10+10) laminated | Toughened · SGP | SGP interlayer for post-breakage retention; low-iron specified |
| Flying glass stringer | 21.5 mm laminated | Structural lam | PE-stamped engineering calculations required per panel |
| Glass tread · walk-on | 8+8+8 or 10+10 + sacrificial top | Walk-on lam | Anti-slip frit, fritted dots, or sandblasted top face — never bare polished |
| Acoustic panel | 6+1.14+6 acoustic PVB | Acoustic lam | For staircases adjacent to bedrooms or media rooms |
Selection matrix
Substrates, tints & decorative treatments
Where each finish earns its place on a CAworks staircase.
| Substrate / treatment | Character | Best applied to |
|---|---|---|
| Clear float | Standard | Hidden infills, where edges are concealed and the panel is thin |
| Low-iron · ultra-white | Crystal | All thick laminates, all exposed edges, all white-walled interiors |
| Tinted grey / bronze | Solar | South-facing atria — controls heat gain and softens harsh daylight |
| Tinted green / blue | Atmosphere | Atmospheric statement walls; less common on stairs proper |
| Frosted · acid-etched | Diffused | Bedroom-adjacent balustrades; full-height privacy panels |
| Sand-blasted | Pattern | Decorative pattern work, gradient frosts, logo etching |
| Back-painted | Solid colour | Riser cladding on glass-tread stairs; bold accent walls |
| Digital UV print | Imagery | Bespoke artwork, botanical motifs, calligraphy, brand graphics |
| Gold-leaf · verre églomisé | Heritage | Statement panels for villas and showrooms — our signature finish |
| Switchable · PDLC | Functional | Glass between staircase and bedroom; on-demand privacy |
| Interlayered · mesh / fabric | Couture | Bronze mesh, silk, gold-finish weave laminated into the panel — bespoke commissions |
Clear glass is the default everywhere except where it actually matters. Once the edge is visible, only low-iron will do.
CAworks workshop principle
Part Three · Timber
Hardwoods for treads, handrails & cladding
Timber on a staircase is the surface that gets touched every day. Hardness decides how a tread survives a decade of stiletto heels and small dogs. Dimensional stability decides how it behaves between a chilled lobby and a 45°C terrace. Durability decides whether it can live near a pool. The figures below compare the species we keep on rotation — with a bias toward what is reliably available in Dubai.
Figure 10 · Surface hardness
Janka hardness
The force required to embed a steel ball half its diameter into the wood — the international standard for flooring and tread hardness.
What this shows. Oak, Ash and Beech form a tight cluster at the top — all three resist tread wear well. Teak and Walnut sit lower than most people expect; their value lies elsewhere. Meranti is genuinely soft, which is why we use it under cladding or as a paint-grade core rather than as a finished walking surface.
Figure 11 · Dimensional stability
Movement with humidity
How much each species swells and shrinks between a dry winter villa and a humid summer one.
What this shows. Stability matters as much as hardness on a UAE staircase. Teak and Iroko move very little between seasons — they earn their place on open atria and pool-facing treads. Beech is hard but moves the most of the seven — fine in a climate-stable interior, risky if it crosses temperature zones.
Figure 12 · Outdoor durability
Rot & weather resistance
How each timber performs in UAE coastal conditions — sun, humidity, and occasional water contact.
What this shows. Teak is the benchmark — its natural oils have made it the boat-deck timber for centuries. Iroko comes close at a fraction of the supply-chain complexity. Oak and Ash are interior species; outside, they need rigorous finish maintenance. Meranti and Beech should not be specified anywhere they will see weather.
Selection matrix
Where each species earns its place
Our default specification by staircase context.
| Timber | Character | Best applied to | Notes |
|---|---|---|---|
| Meranti | Soft hardwood | Paint-grade cores, cladding substrates, hidden carcass work | Soft surface — never specify as a finished walking face |
| Beech | European | Interior treads in climate-stable rooms, lacquered finishes | Hard but moves with humidity — avoid open atria |
| Ash | European | Modern light-toned interiors, Scandinavian-style staircases | Excellent value; pairs well with white-painted stringers |
| Iroko | African | Warm-toned treads in semi-exposed locations; pool-adjacent stairs | The honest teak alternative — same oil content, same stability |
| Oak | European | The default tread for glass balustrade staircases; broad finish range | European white oak preferred over American red oak for stability |
| Walnut | N. American | Dark, luxury residential interiors — formal living rooms and libraries | Beautiful grain; softer than oak — light wear shows over years |
| Teak | Tropical | Premium villa staircases, wet areas, pool houses, exterior treads | The benchmark for everything; chain-of-custody certification matters |
A staircase is read with the hands and the feet before the eyes. The choice of timber is the moment we either honour that, or fail it.
CAworks workshop principle
Part Four · Marble
Marble finishes for treads, risers & landings
On a marble staircase the choice of stone is the first question; the choice of finish is the second, and just as decisive. The same slab of Calacatta reads as a hotel lobby in polish, a private library honed, a coastal villa leathered. Beyond appearance, finish governs how the tread performs — its grip when wet, the way it ages under bare feet, how visible the next decade of wear will be. The figures below compare the seven finishes we specify, against the German DIN 51130 slip standard that UAE consultants now reference by default.
Figure 13 · Slip resistance
DIN 51130 ramp rating by finish
German ramp-test classification — R9 (low) through R13 (high). The standard now referenced by Dubai Municipality on residential stair specifications.
What this shows. Polished marble is not classified for slip resistance under DIN 51130 — it cannot be rated. In practice this means polished treads are acceptable only in dry, climate-controlled interiors. Honed is the minimum we specify for any residential tread. Bush-hammered and flamed dominate exterior and pool-adjacent stairs; both can be applied to denser marbles, though softer Italian whites generally do not tolerate the heat-shock of flaming.
Figure 14 · Wear visibility
How well each finish hides wear
How obviously a decade of foot traffic and the occasional dropped object will register on the surface.
What this shows. Polished surfaces are mirrors — every scratch, every dulled edge from a stiletto reads instantly under directional light. Textured finishes (leathered, brushed, bush-hammered) absorb wear into their own surface character. This is one reason honed is the long-running default for stair treads in working homes; polished marble belongs in showpieces, not service areas.
Figure 15 · Maintenance
Ongoing care burden
How frequently each finish demands re-sealing, re-polishing, or specialised cleaning to keep its appearance.
What this shows. Counter-intuitively, polished marble is the most demanding finish over time — it shows damage, requires periodic re-polishing by a contractor with diamond pads, and reveals etch marks from any acidic spill. Textured finishes need only routine re-sealing every two to three years. Honed sits in the middle: easy to live with, easy to refresh in-place by the same trade that installed it.
Selection matrix
Where each finish earns its place
Our default specification by staircase context and stone type.
| Finish | Character | Best applied to | Notes |
|---|---|---|---|
| Polished | Formal | Showpiece lobbies, formal entrance halls — dry interiors only | Not slip-classified · re-polishing every 5–7 years |
| Honed | Contemporary | The default tread finish — residential, hospitality, contemporary interiors | Soft matte; reseal every 2 years |
| Leathered | Tactile | Premium villas, master suites — where the hand reads the surface | Light pebbled texture; conceals etch marks beautifully |
| Brushed · antiqued | Aged | Mediterranean-style interiors; rustic luxury villas | Wire-brushed surface; softens harder marbles visually |
| Sand-blasted | Matte | Modern interiors needing slip resistance without heavy texture | Uniform matte; good middle ground for kitchen-adjacent stairs |
| Bush-hammered | Architectural | External terraces, pool surrounds, semi-exposed entrance stairs | Aggressive texture; only on hard marbles like Emperador or Nero |
| Flamed | Exterior | External stair treads, ramps, hardscape adjacent to staircases | Generally for granite; only the densest marbles tolerate the process |
| Tumbled | Rustic | Heritage-style villas, traditional interiors with character | Rounded edges; the most informal finish in the range |
Selection matrix
Stone varieties for stair work
The marbles we keep on rotation, and how each takes a finish.
| Variety | Origin | Character | Finish notes |
|---|---|---|---|
| Carrara | Italy | Soft white-grey with fine feathered veining | Honed reads softest; polished can grey-over in damp interiors |
| Calacatta | Italy | Bold grey-and-gold veining on a clean white field | Polished maximises the veining drama; honed makes it residential |
| Statuario | Italy | The most premium white marble — pure ground, dramatic veins | Always polished or honed — never textured; reserve for showpieces |
| Crema Marfil | Spain | Warm beige with light, uniform veining; the workhorse warm marble | Takes every finish well; brushed and leathered look exceptional |
| Emperador | Spain | Rich dark brown, fine grain, dense and harder than the whites | Excellent for bush-hammered and flamed; outdoor-capable |
| Nero Marquina | Spain | Deep black field with sharp white veining | Polished is dramatic but high-maintenance; honed is the safer luxury |
| Botticino | Italy | Soft cream with cloud-like figuring | Forgiving across all finishes; honed is the residential default |
The marble decides the room. The finish decides the staircase. Choose the finish for how the tread will be used, not how it will be photographed.
CAworks workshop principle
UAE compliance
Building code.
Beauty starts with proportion, and in the UAE proportion starts with the code. Every staircase begins by anchoring rise, going, headroom and handrail height against the Dubai Building Code 2021, the Dubai Universal Design Code, the UAE Fire & Life Safety Code of Practice and the Trakhees Building Regulation Design Guidelines. The numbers below are not preferences — they are the minimums and limits the Authority checks on every drawing before a slab is poured.
Rise & going — the only two numbers that decide if a stair is walkable.
Set these first; flight length, landing position and headroom all follow. Internal and external stairs are treated separately because shoes, weather and the heel-strike angle of a descent are not the same outdoors.
Internal stairs
- Riser (max)≤ 175 mm
- Going (min)≥ 270 mm
- Recommended riser150–165 mm
- Recommended going300–340 mm
External stairs
- Riser (max)≤ 165 mm
- Riser (preferred)150 mm
- Going (min)≥ 280 mm
- Going (preferred)350 mm
Villa stairs · DBC Part K
- Riser (max)≤ 200 mm
- Going (min)≥ 240 mm
- All treads identicalRequired
- Step height tolerance± 4 mm
Why two different sets of numbers?
The Trakhees Blue Code sets the floor — minimums for any habitable building in Dubai's free zones. The Dubai Universal Design Code sharpens those into an accessibility-graded comfort band the Dubai Building Code adopts by reference. Where the DUDC is stricter, the DUDC wins. The recommended 150–165 mm riser and 300–340 mm going sit inside both windows, which is why most architects specify within that range without thinking.
2R + G — the Blondel relationship, with UAE-specific bounds.
A 350-year-old proportion rule that hasn't been improved on. The average adult stride doesn't change between Paris in 1672 and Dubai in 2026, so the formula remains the cleanest sanity-check an architect has against a drawing.
What the formula actually tests
When you climb a stair, your foot rises twice as far vertically as it travels horizontally on each step. The 2R + G sum approximates the diagonal length of one full pace. Stay below 620 mm and the stair feels cramped; go above 700 mm and the climb feels lazy and the footing uncertain.
• 2×165 + 300 = 630 mm — brisk, tight
• 2×160 + 320 = 640 mm — household sweet spot
• 2×150 + 350 = 650 mm — grand entrance, generous
Where a flight ends, and how it turns.
Long uninterrupted climbs are tiring and dangerous; the code forces a rest point at a fixed interval. Landings are also the turning surface where a flight changes direction — they must be wide enough to receive someone arriving at full pace.
Per-flight rules
- Max steps per single flight14
- Step-to-step height tolerance± 4 mm
- Nosing projection≤ 25 mm
- Nosing — preferredAvoided
Landings
- Width≥ stair clear width
- Residential minimum1 100 mm
- Same-direction flights≥ 1 200 mm long
- Door swing into landingProhibited
Why 14 is the magic number
A flight of 14 risers at the maximum 175 mm carries you 2.45 m vertically — almost exactly one storey of residential floor-to-floor height. Anything longer and a slip becomes a serious fall, so the code prefers two short flights with a landing between them over one long climb.
Geometry gets harder the moment the stair stops being straight.
When treads are wedge-shaped, every rule about "going" has to specify where on the tread you measure. The diagrams below are reproduced from the Dubai Building Code 2021, Part K (Villas), Figure K.31. The rules apply to villas, with comparable thresholds for other building types under DBC Part B.
Curved
≥ 255 mm at 305 mm from narrowest edge measured along the walking line
≥ 255 mm at 305 mm from narrowest edge measured along the walking line
Spiral
≥ 190 mm at 305 mm from narrower edge measured along the walking line
≥ 190 mm at 305 mm from narrower edge measured along the walking line
Winders
≥ 150 mm at narrowest, ≥ 280 mm at 305 mm measured along the walking line
≥ 150 mm at narrowest, ≥ 280 mm at 305 mm measured along the walking line
Spiral · DBC §K.5.5.2.8
- Clear width≥ 1 000 mm
- Tread at 305 mm point≥ 190 mm
- Riser height≤ 240 mm
- Headroom≥ 2 030 mm
- As main villa stairNot recommended
Curved · DBC §K.5.5.2.8
- Clear width≥ 1 000 mm
- Tread at 305 mm point≥ 255 mm
- Riser height≤ 240 mm
- Headroom≥ 2 300 mm
- Outer handrailRight of descent
Winders · DBC §K.5.5.2.8(i)
- Tread at narrowest≥ 150 mm
- Tread at 305 mm point≥ 280 mm
- Changes directionYes
- Substitute for landingPermitted
Why the 305 mm rule exists
On a curved or wedge tread no single "depth" number exists — the tread is wider at the outside arc and narrower at the inside. The code measures depth at a fixed point 305 mm in from the narrower edge, because that is where a real foot lands when someone walks the stair. The line connecting those points is the walking line, and every tread must satisfy the minimum depth measured along it.
Clause (h) — outer handrail on the right of a descending user — reflects right-hand dominance: descending, a right-handed person reaches for the rail on their right, so handrail placement on a curved stair is always specified by descent direction.
Three geometries, three different minimums.
Headroom is the vertical clearance from the tread nose up to whatever is overhead — a soffit, a beam, a pendant light. Different stair geometries need different minimums because the head does not track the same path on each.
Straight stair≥ 2 000 mm
Measured perpendicular to the tread nosing. International & DBC default.
Spiral stair≥ 2 030 mm
The body stays close to the centre column; head tracks a tight circle.
Curved stair≥ 2 300 mm
A sweeping descent leans the body out toward the outer arc, projecting the head forward.
Open space under a stair< 2 400 mm
If accessible and below this clearance, it must be guarded against the overhead hazard.
The DBC asymmetry is deliberate
A lower minimum for spirals (2 030 mm) than curved stairs (2 300 mm) looks inconsistent — spirals are tighter, why is the figure lower? Geometry: on a spiral the body hugs the centre column and the head tracks a tight circle, so the ceiling can sit lower without contact. On a sweeping curved stair the body leans out toward the outer arc on descent and the head projects forward of the tread — the 2 300 mm figure protects that projection.
What you actually hold.
The interface between the stair and the human body. Compliance failures here are the most common reason a snag-list is rejected at handover.
Position
- Mounting height900 mm
- Second rail (children)650–750 mm
- Both sides if Δlevel > 500 mmRequired
- Extension top & bottom≥ 300 mm
- Intermediate rail if width > 2 100 mmRequired
Grip geometry
- Circular profileØ 30–40 mm
- Elliptical profile50 × 40 mm
- Clearance to wall30–60 mm
- Underside support clearance≥ 50 mm
- Reflectance contrast≥ 30 LRV
Why the 300 mm extension matters
A handrail that ends exactly at the top tread leaves a user mid-grip when they reach the landing. The 300 mm horizontal continuation past the top and bottom step gives the hand an anchor through the transition between climbing and walking — the moment where most falls actually happen.
The vertical barrier that stops a fall.
A balustrade is not a handrail. The handrail is what you hold; the balustrade is the wall of protection between the stair edge and the void beside it. The UAE measures both — height, climbability and material — independently.
Heights & geometry
- Min height — stair edge≥ 900 mm
- Min height — balcony / terrace / landing≥ 1 200 mm
- Open-riser sphere testØ 100 mm cannot pass
- Climbable elements belowNone within 760 mm of FFL
Why glass must be laminated, not just toughened
Toughened (tempered) glass is strong, but when it breaks it breaks completely — turning into thousands of small dice at once. Laminated glass is two or more sheets bonded by a polymer interlayer, so if one ply fails the interlayer holds the fragments and the panel keeps residual load capacity until replacement. The UAE FLSC requires safety glass in any handrail or guard for exactly this reason — a balustrade that could vanish on impact is not a balustrade.
Two regulations most architects miss.
Easy to overlook in a beauty shot. Both are picked up on the first inspection.
- Illumination ≥ 200 lux at the top, the bottom and along the flight. Pendant fittings over voids count toward this; LED tread strips supplement but rarely meet it alone. Stair lighting is checked at handover with a calibrated lux meter. DUDC §5.8
- Step-edge contrast ≥ 30 LRV points over the first 30 mm of the nosing — the tread edge must visually distinguish itself from the tread face. The dark line on most timber treads at the nose is doing exactly this job; on stone or concrete it is a contrasting inlay or sandblast stripe. DUDC §5.8
- Slip resistance — PTV ≥ 36 dry; ≥ 36 wet (external). The Pendulum Test Value benchmark from BS 7976 applies to any walking surface; Dubai Municipality accepts it as the working standard for stairs. Brushed steel, honed natural stone and sandblasted glass treads all comfortably exceed it. BS 7976 · DM guidance
The 11 m rule.
One of the more visually-restrictive clauses in the code — often missed at concept stage and expensive to correct.
- External stairs more than 11 m above finished ground level must be enclosed on the open side by an opaque visual obstruction not less than 1 200 mm in height. Frameless clear-glass balustrades fail this clause; the design needs an opaque infill, a solid parapet, or a fritted / ceramic-coated glass the Authority accepts as visually opaque. The rule prevents vertigo-induced misstep on long external climbs. DBC Part K §K.5.5.2.7
The documents every UAE staircase is designed against.
Linked to the official publishers. The DBC is the apex reference; the DUDC tightens accessibility; Trakhees governs Dubai Free Zones; the FLSC governs glazing and fire-safety material spec.
Dubai Building Code 2021 — full PDF
843 pages · the binding reference for every clause cited above. Hosted here for a direct download.
↓ Download PDF
- Dubai Building Code 2021 (DBC) Issued by Dubai Municipality. Part B (Architecture) and Part K (Villas) carry the binding stair-geometry, headroom and external-stair rules cited throughout. Direct download → Official source →
- Dubai Universal Design Code (DUDC) The accessibility-graded sharpening of stair geometry, handrail dimensions and visual contrast. §5.8 covers steps, §5.9 covers handrails. §5.8 Steps → §5.9 Handrails →
- UAE Fire & Life Safety Code of Practice (FLSC) Issued by Dubai Civil Defence. Governs glazing material specs for handrails and guards, stair pressurisation and egress widths. Dubai Civil Defence →
- Trakhees Building Regulation Design Guidelines (Blue Code) The Free Zone equivalent of the DBC (TECOM, JAFZA, DAFZA, Dubai South). §13 covers vertical circulation. §13.1 →
- DDA Updated Building Code for Guardrails & Openable Windows Dubai Development Authority addendum on guardrail heights (1 200 mm minimum) and climbability. Read with the FLSC for glass material spec. Read PDF →
Process
Five stages from architect's drawing to handover.
Every helical staircase moves through the same five stages. Each one is signed off in writing before the next begins — that's how we keep site work predictable and decisions reversible while they're cheap to reverse.
01
Site survey & templates
We arrive on site with 3D scanning equipment and physical templates. The opening, the structural slab edges, the finished floor level, the wall conditions — everything is captured to ±1mm before we touch a drawing.
- 3D laser scan of the staircase void
- Physical templates for non-standard openings
- FFL datum marked and photographed
- Site survey report issued to architect within 5 days
02
3D model & engineering review
The survey data becomes a full 3D model of the staircase — every stringer plate, every tread, every fixing detail. The model is shared with the architect for design coordination, and our in-house structural engineering team verifies every connection under domestic and commercial load cases.
- Full BIM-compatible 3D model (IFC export available)
- Up to two non-principal design revisions included
- Structural calculations against UAE / Dubai Building Code
- Architect approval gate before fabrication drawings
03
Fabrication drawings
Once the 3D model is approved, we issue a full fabrication drawings set: stringer geometry sheets, tread schedules, connection details, glass cutting list with curve radii, handrail and balustrade fixing details. Cross-referenced to the model so the workshop can build directly from it.
- Full fabrication drawings set, sealed
- Glass cutting list with bend radii and edge work
- Connection details for every fixing
- Issued to client and workshop simultaneously
04
Workshop fabrication
Steel stringers are 3D-bent and laser-cut to the helix geometry. Treads plasma-cut to the trapezoidal shape, edges deburred and joints polished. The full staircase is dry-assembled in the workshop before disassembly for shipping — every connection trial-fitted under our supervision.
- 3D-bend laser-cut S275 stringers, polished joints
- Plasma-cut trapezoidal treads, deburred
- Full dry-assembly trial-fit in workshop
- Daily progress logs with photo documentation
05
Site installation & handover
The staircase is delivered to site in pre-assembled segments. Our installation team rigs, sets out, levels and connects the staircase, fits the glass balustrade panels into channels, installs the handrail, snags the work, and hands over with a full installation log and operations & maintenance package.
- Pre-assembled segments, crane-lifted into place
- Glass balustrade fitted to channels on site
- Handrail joints machined to final radius in shop
- Daily logs and snag list issued through Buildertrend
- Sheen Lane reference: similar double-stringer install workflow
