Glass Balustrade Regulations: Heights, Loads and Glass

Glass balustrades are covered by the same rules as any other guarding: how high they must be, how strong they must be, and what happens if a panel breaks. Here's what applies, in plain terms.

Which rules apply

• Approved Document K (protection from falling) sets where guarding is needed and how high it must be.
• BS 6180 (barriers in and about buildings) sets how strong a barrier must be for the way the space is used, and covers glass barriers specifically.
• Building control checks that the design meets both, and signs off the work.

How high a glass balustrade must be

Approved Document K gives minimum heights, measured from the floor or from the pitch line of the stair:

• Stairs and ramps: 900mm.
• Balconies, landings and the edges of floors: usually 1100mm. The main exception is landings and floor edges inside a house, where 900mm can be enough.

These are minimums. Where people might lean on the barrier or gather against it, such as bars, terraces and mezzanines, a designer will often go higher.

How strong it needs to be

A balustrade has to resist people leaning, pushing and crowding against it. BS 6180 sets the load a barrier must take, and it depends on how the space is used. A balustrade in a house is designed for much lower loads than one in a bar, a shopping centre or a stadium, where crowds can push against it.

That load decides the glass thickness, the fixings and the handrail. It's why two balustrades that look the same can be very different underneath.

What glass is used

Balustrades use safety glass, normally toughened and very often toughened laminated. Laminated glass is two or more sheets bonded with an interlayer, so if a sheet breaks, the pieces stay stuck to the interlayer and the panel stays in place.

That matters because a barrier must still protect people if the glass breaks. There are two common ways to achieve that:

• Laminated glass designed to stay in place after breakage. This is how most frameless balustrades work.
• A handrail that ties the panels together, so a broken panel can't leave a gap.

For example, the internal balustrade we fitted at Ravensworth House used 21.5mm toughened laminated glass with powder coated handrails.

Gaps and climbability

Where children might use the space, the balustrade must not have openings that a 100mm sphere can pass through, and it shouldn't be easy to climb. Glass helps here: a full-height panel has no gaps or footholds. The gaps to check are under the glass, between panels, and at the ends of runs.

Fixing types

• Posts and clamps: glass panels held between steel or stainless posts. Simple, economical and easy to replace.
• Channel (frameless): glass set into a continuous channel fixed to the floor or the side of the slab, with no posts. Clean-looking, but it depends on a strong fixing into the structure.
• Standoff or point fixings: glass fixed through bolts to the edge of a stair or slab.

What the balustrade fixes into matters as much as the glass. A barrier is only as strong as the floor or stringer it's fixed to, which is why the steel behind it is part of the design.

Frequently asked questions

Does a glass balustrade need building regulations approval? When it's part of building work, such as a new stair, balcony or mezzanine, yes. Building control will check its height and strength. See mezzanine floor building regulations for a related example.

Is a top handrail required? Not always. Frameless glass can work without one if the glass is designed to stay in place if it breaks. A handrail is still needed on stairs for people to hold, and a top rail can make thinner glass possible.

Can glass balustrades be used outside? Yes, on balconies and terraces. Exposure to wind and weather affects the design, and on the coast the fixings and coatings need to resist salt. Our Tynemouth Castle Inn balustrades are an example.

Do you make glass balustrades? Yes. We design, fabricate and install glass balustrades for stairs, balconies and mezzanines. Tell us about your project.