In a corporate lobby, the staircase is the first thing a visitor reads — before reception, before signage, before anyone speaks. When that staircase is built almost entirely from glass and appears to float without columns, it stops being circulation and becomes the building's signature. That is the brief Shanghai Shanzhi Stair Technology Co., Ltd. answered for an office tower in Zhuhai, where a curved glass stair now sweeps through a glass curtain-wall lobby with no visible support structure beneath it.

A Stair That Lets the Facade Finish the Sentence

The Zhuhai project was designed around one idea: glass and steel as the only two languages spoken in the room. The stair's plan curve mirrors the curtain wall that surrounds it, so the two read as one continuous architectural gesture rather than a component dropped into a hall. Daylight passes through the facade, then through the treads and balustrade, and lands on the floor as a moving grid of light and shadow. The tempered laminated glass stops being a surface and becomes an instrument for handling light.

The structure is deliberately absent from the visual story. There is no redundant support below the flight — the span is closed entirely through cantilever mechanics, with the load path resolved into the concealed steel spine and the building's anchoring points. What a visitor sees is a clean rising arc; what the engineer sees is a calculated moment curve.

How a Cantilevered Glass Flight Actually Works

Buyers and specifiers ask the same question first: what holds it up? On a stair of this type, the answer is a curved steel stringer or box beam that carries the vertical and torsional loads, plus a set of purpose-made stainless fittings that transfer each glass tread and balustrade panel into that spine. The treads are laminated tempered glass; the balustrade is a continuous glass plane rather than a series of posts. Because glass cannot be drilled and re-drilled on site without weakening it, every hole position, every radius, and every panel length has to be fixed at the drawing stage and cut to match.

That is where the difficulty concentrates. A curved flight changes radius, pitch, and elevation simultaneously, so no two balustrade panels are identical and no tread is a repeat. Each piece is drawn individually, cut individually, and labelled for its exact position. When the geometry is right, the result is a stair with even joints, a continuous top line, and a structural presence so light that clients routinely describe it as a sculpture. When the geometry is off by a few millimetres, the whole sequence fails at installation. Precision is not an aesthetic preference here — it is the only way the assembly closes.

One Capability, Many Building Types

Over 36 years, the same structural discipline has been applied across a wide spread of project types, and the range is the clearest evidence of what the factory can absorb:

Corporate and R&D interiors — the Zhuhai curtain-wall lobby, a cantilevered steel and glass stair at a Gree research building, and a white steel and glass stair for an office fit-out in Beijing where the flight had to clear a tight wall line and land cleanly at the slab opening.

Retail and brand flagships — a fully integrated spiral stair for a Huawei flagship store in Tianjin, with a seamless single-surface finish and a glass balustrade sunk flush into a pre-formed floor channel; a suspended glass stair for a Jordan flagship where one flight appears to vanish behind mirror-polished stainless cladding and a third flight becomes a red-lit corridor.

Hospitality and public buildings — a near-13-metre multi-curve steel spiral for a wine-country resort lobby, a red spiral inside a converted industrial hotel, and three large cantilevered steel stairs for an arts centre, built to public-building scale and traffic load.

Residential and villas — full-glass suspended flights anchored into hidden wall fixings, spiral stairs with asymmetric balustrades, and compact wall-hugging glass spirals for tight floor plans.

Exterior and marine conditions — an outdoor spiral wrapping a headquarters facade in fluorocarbon coatings, sealed glazing gaskets and fully enclosed light channels; and a large-span cantilevered glass stair installed in the atrium of a domestically built cruise ship, where the full assembly passed SOLAS safety certification for ocean service.

Built for Weather, Not Just for Photographs

An outdoor stair is a different engineering problem from an indoor one. For the Shenzhen exterior spiral, the finish specification runs to UV-stable fluorocarbon topcoat against acid rain, tempered glass balustrades bedded with dedicated waterproof gaskets, sealed and dust-proofed channels, and light strips housed in fully enclosed waterproof cavities. For a landscaped outdoor flight, the steelwork carries a hot-dip galvanised base plus an exterior topcoat system, with timber components heat-treated and oiled for moisture and sun exposure. International buyers comparing suppliers should ask specifically which of these layers is included in the quotation — the visible difference between a stair that survives five winters and one that does not usually lives in coatings and sealants, not in the profile.

Factory, Team and Delivery Model

Shanzhi operates as a source factory rather than a trading intermediary. Two production bases total roughly 66,000 square metres: a 6,000 square metre facility in Taicang, Suzhou, and a 60,000 square metre campus in Hubei that includes a dedicated glass stair workshop of over 10,000 square metres with 12-metre eave height, built for oversized and sculptural glass flights. Equipment includes CNC laser cutting, shaped glass processing and metal curved-surface forming, supported by an in-house R&D, technical, inspection, production, sales and service structure, with a team of more than 300 and installation crews carrying 10 to 30 years of hands-on experience.

Component pre-assembly happens in the factory before shipping — arcs, splice alignment and coaxiality are verified in the workshop so that site work becomes assembly rather than correction. The company holds multiple patents, reports exclusive domestic capability in curved all-glass stair fabrication and installation, and has delivered more than 5,000 projects. Recognition includes a Top Ten Innovative Stair Design Brand award at the 2025 Shanghai Stair Exhibition and a Breakthrough of the Year award from the owner of a resort project in Yinchuan.

What to Send When You Request a Quotation

To return a workable proposal quickly, the design and estimating team needs: architectural plans and sections with floor-to-floor height, the available stair opening dimensions, intended finish and material direction, indoor or outdoor exposure, expected traffic load and any local code requirements for balustrade height and glass build-up. Concept sketches are enough to start — the engineering, modelling and material selection follow from there. For overseas projects, drawings and shop documents are issued in English, with factory pre-assembly and installation guidance available as part of the delivery scope.

Talk to the Factory Directly

If you are an architect, contractor, developer or distributor specifying a cantilevered glass or curved steel staircase, send the drawing set for a technical review and budget indication.

Shanghai Shanzhi Stair Technology Co., Ltd.
Phone / WhatsApp: +86 13682366366  |  +86 18201966366
WhatsApp / Skype: +86 1368236636
Email: Tongruishiye@163.com
Website: https://www.sinestair.com/

Send one section drawing and one photograph of the space. That is usually enough to tell you whether the stair you have in mind can be built the way you want it.