Sky-Frame Arc is a frameless sliding window system for curved glass facades. The radiused insulating glass units run in curved tracks fitted flush with floor and ceiling, so rounded building contours can be glazed and opened without visible frames. Curved elements can be combined with straight Sky-Frame Classic runs and with successive curves, allowing convex, concave and S-shaped facade lines within one system.
Construction
Arc follows the same construction principles as the straight systems: insulating glass units with perimeter sections in aluminium and glass-fibre-reinforced plastic, concealed frames flush with floor and ceiling, and a level threshold with integrated drainage. The curved units are produced to the project radius and matched to the adjoining straight runs. The rounded glass is engineered for consistent running performance along the curve, manual operation with low rolling resistance is standard, and the daylight-to-glass ratio matches the straight systems at 98 per cent.
Glazing technologies
Arc is manufactured with Sky-Frame 2 (30 mm double glazing) or Sky-Frame 3 (54 mm triple glazing). The feasible geometry is defined by radius and track count:
| Configuration | Sliding elements | Fixed elements |
| Two-track | radius 3.5 to 10 m | radius 2.5 to 10 m |
| Three-track | radius 5.0 to 10 m | radius 5.0 to 10 m |
Sliding elements measure up to 2.0 x 3.1 m and fixed elements up to 2.4 x 3.1 m; other radii and wider elements are available on request.
Opening layouts
Opening layouts include side, centre and offset arrangements along the curve. An electric drive can be integrated with Sky-Frame 3: motorised operation is possible in two-track configurations from a radius of 3.8 m and in three-track configurations from 5.0 m. The drive is concealed in the ceiling section and moves the panels at the press of a button.
Features
Depending on configuration, Arc can be combined with further Sky-Frame features such as switchable glass, security hardware or Pocket; compatibility is verified per project.
Applications
Arc extends frameless glazing beyond rectilinear floor plans. Typical applications include rounded building corners, cylindrical or organically shaped volumes and interiors in which a curved glass front contrasts with an otherwise linear composition, in residential architecture as well as hospitality and commercial buildings.
Colours and manufacture
Seven anodised finishes are supplied as standard: the colourless E6/EV1 and six chemically mattened Colinal tones. Further anodised colours are available on request, as is powder coating in the RAL, IGP and DB colour systems, applied in-house to the Qualicoat standard. All components are developed and manufactured in Switzerland; more than 15,000 projects have been realised since 2002.
Download the latest documentation and CAD drawings for more information about Sky-Frame sliding systems.
