Glass facades can look almost weightless, yet every square metre of them has to resist wind, carry its own dead load and move with the building without leaking or cracking. Of all the ways to achieve that, the point-supported curtain wall is the most visually minimal — and one of the most demanding technically. Instead of gripping each pane in a continuous aluminium frame, a point-supported system holds the glass at a handful of discrete connection points, letting the panels appear to float in front of the structure. The result is a facade with uninterrupted vision, razor-thin joints and a level of transparency that framed systems simply cannot match. This guide explains how the system works, what governs its engineering, and where it makes the most sense on real projects.
What Defines a Point-Supported Curtain Wall
In stick-built and unitized curtain walls, glass is captured along its entire perimeter by aluminium profiles, gaskets and pressure plates. That continuous frame does two jobs at once: it carries the loads and it provides the weather seal. A point-supported curtain wall separates those two functions. The continuous frame disappears, and each glass panel is held at a limited number of points — typically four corners — by bolted fittings, patch plates or multi-arm spider connectors. Wind pressure, glass self-weight and thermal movement are funnelled through those few connections into a supporting substructure, which may be steel mullions, glass fins, cable nets, space frames or trusses tied back to the building.
Because the glass is only restrained at its corners, it behaves structurally more like a plate spanning between supports than a pane clamped on all edges. That changes everything about the design: the glass must be thick enough to control deflection between fittings, the holes must be positioned with precision, and the connections must allow for small rotations and movements without introducing stress concentrations. The visual payoff is significant — flush glass surfaces, narrow silicone joint lines instead of wide aluminium caps, and an envelope that reads as a single sheet of glass rather than a grid of frames.
Connectors come in two broad families. Rigid spiders clamp the glass firmly and are used where the substructure is stiff and movements are small, while articulated spiders use rotating arms and bolted joints that absorb thermal expansion, wind-induced sway and construction tolerances. Most high-quality assemblies combine stainless steel fittings with isolation bushings that keep metal from touching glass directly, preventing hard contact and galvanic interaction while permitting controlled movement.
It is worth being clear about the trade-off. Point-supported glazing delivers exceptional transparency and suits architectural feature areas beautifully, but it concentrates load into very small areas of glass, requires drilled and specially processed panes, and relies on sealant joints rather than a continuous pressure-equalised frame for weather tightness. Compared with a fully framed unitized facade, it also offers less inherent thermal separation, since every fitting is a potential thermal bridge. Those are not flaws — they are design conditions that have to be engineered deliberately.
Glass, Hardware and the Engineering Details That Matter
Everything in a point-supported system begins with the glass make-up. Panels are normally heat-strengthened or fully tempered, and laminated assemblies are common because the interlayer keeps broken glass in place and provides residual capacity if a pane is damaged. Heat-soak testing is frequently specified to reduce the risk of spontaneous breakage from nickel sulphide inclusions in tempered glass. Thickness is determined by structural calculation rather than by rule of thumb, and the position of every hole matters: edge distances, hole spacing and hole diameter all influence stress around the connection, so holes are drilled before toughening, using CNC equipment to hold tight positional tolerances across the whole panel.
The hardware carries the load, so its specification is not a detail to be value-engineered away. Fittings are usually stainless steel, with grades selected for the corrosivity of the site, and spiders may be cast or machined aluminium with stainless arms. Isolation bushings and washers separate glass from metal, countersunk bolts sit flush with the surface, and articulated connections allow the panel to rotate slightly as the structure deflects. Installation crews work to controlled torque values, because an under-tightened bolt allows movement and an over-tightened one can crack the glass around the hole.
Structural analysis has to consider far more than wind pressure. Dead load hangs from the upper fittings, so the glass must be checked for the resulting in-plane stresses. Seismic drift, building sway and thermal expansion of both glass and substructure must be accommodated through movement joints rather than resisted. Deflection limits apply to the glass and to the supporting members, since visible flexing undermines the whole aesthetic. Redundancy is also part of the brief: a laminated panel that loses one ply should still remain safely in its fittings, and the loss of a single connector should not lead to progressive collapse.
Because so much depends on fit and alignment, a full-size mockup is standard practice on serious projects. A 1:1 assembly lets the team verify hole alignment, tolerance stack-up between glass and substructure, sealant behaviour and water performance before production begins. Factory-controlled cutting, drilling and machining of fittings, together with an in-house quality lab, keep those tolerances repeatable across hundreds of panels — which is exactly what a system with almost no visual margin for error requires.
Where Point-Supported Facades Work Best — Applications, Installation and Specification
Point-supported glazing shines wherever the design intent is maximum transparency in a defined area. Typical applications include entrance lobbies and reception areas, atria and skylights, retail frontages, stairwells and feature walls, canopies, and view corridors in commercial and hospitality buildings. It is also popular on education and public buildings where daylight and openness are part of the architectural brief. On tall towers, the system is more often used for podium levels, double-height entrances and feature zones, while unitized curtain wall takes the main envelope where speed of installation and consistent weather performance over large areas matter more. Many projects combine all three approaches.
Installation follows a strict sequence. The substructure is surveyed and set out first, then brackets and mullions or cable assemblies are installed and aligned. Spiders are positioned to tight tolerances, panels are lifted into place, articulated bolts are engaged and torqued in the correct order, and the joints are sealed with structural and weather silicone. Access planning matters as much as the glazing itself: replacement routes for damaged panels, cleaning access and maintenance of exposed fittings should be considered during design, not after handover. Large panels also demand careful logistics — custom sizes and long spans need export-grade packing and sea-worthy crating so that edges and drilled holes arrive undamaged.
When specifying, it helps to set out performance requirements clearly: design wind loads, glass make-up and heat-soak requirements, fitting material and finish, expected structural movements, water and air tightness targets, and the mockup and testing regime. From there, reviewing how a supplier handles tolerances, custom dimensions and project-order fabrication makes the comparison far more concrete — the full range of unitized and stick-built options alongside point-supported assemblies is laid out in the curtain wall systems catalogue, where more details here cover substructure types, glazing configurations and fabrication capabilities for residential, commercial and public building envelopes worldwide.
Kathmandu astro-photographer blogging from Houston’s Space City. Rajeev covers Artemis mission updates, Himalayan tea rituals, and gamified language-learning strategies. He codes AR stargazing overlays and funds village libraries with print sales.