Glass Balustrade Calculator

Approved Document K (2013, England) sets the minimums for a single dwelling: 900mm for stairs, landings, ramps and the edges of internal floors, and 1100mm for external balconies, Juliet balconies and the edges of roofs. Guarding is required wherever there is a drop of more than 600mm. In other buildings (flats, offices, public) the figures are 900mm on flights and 1100mm elsewhere. Heights are measured from finished floor level (or the pitch line on stairs).

Where a continuous handrail caps the panels, framed systems commonly use 15mm monolithic toughened glass (to BS EN 12150). Frameless systems with no top rail rely on the glass alone, so use toughened-laminated glass — typically 17.5mm or 21.5mm (two toughened panes bonded with a PVB interlayer to BS EN 14449) so a cracked panel stays in place. Heat-soaking (BS EN 14179) is advised externally to reduce nickel-sulphide spontaneous breakage. Confirm the exact spec with your system manufacturer for the span and load.

These are indicative trade figures, not a fixed schedule — always get a site quote. As a glass-supply-only rate (before fixings and fitting), post-mounted is around £250/m, side-fixed clamps around £320/m, base-fixed channel around £380/m and frameless structural glass around £520/m. The calculator adds roughly £45/m for fixings and your install rate (default £80/m) on top, so a typical all-in supply-and-fit total lands near £375/m post-mounted, £445/m side-fixed, £505/m base-fixed and £645/m frameless. External locations and taller panels push these higher.

Yes. They must satisfy Part K (protection from falling) for guard height and the structural loads in BS 6180 / BS EN 1991-1-1. For a single dwelling the horizontal line load is 0.36 kN/m (Category A — external balconies and roof edges are excluded from this lowest category); retail, assembly and similar areas are higher (1.5 or 3.0 kN/m). The glass itself is safety glass to BS 6262-4 (impact safety), toughened to BS EN 12150 and, where laminated, BS EN 14449. This calculator estimates cost only — it does not perform the structural check.

Yes, with appropriate glass specification. External balustrades should use heat-soaked toughened laminated glass to reduce risk of spontaneous breakage from nickel sulphide inclusions.