Railing (balustrade)

A railing, or balustrade, is the barrier built along any open edge where there is a drop. You find it on stairs, balconies, roof terraces, gallery voids and ramps. It usually carries a handrail on top, the part your hand actually grips, while the infill below can be balusters, glass, perforated metal or tensioned cable.

What matters in practice

A railing is a safety element first and a design element second. Its height, the size of gaps in the infill and its resistance to horizontal loads are all set by building regulations, and designs with horizontal bars that children can climb are generally avoided. With glass balustrades, the glass type and the way it is clamped or channel-fixed matter; with metal ones, so does how the posts are anchored into the slab or its edge. On a waterproofed terrace, fixings must not puncture the membrane, or must be sealed properly where they do. On stairs, a continuous handrail with a profile the hand can wrap around makes a real difference to everyday comfort.

Railings in visualization

A railing is a thin line that tells you the rhythm and scale of a facade. Balusters modelled too thick make a building look heavy, while a missing railing makes the scene feel unfinished. For glass, a faint green edge tint and believable reflections do the work; for metal, the right roughness value. On balcony and terrace shots, the shadow pattern a railing throws across the floor is often one of the nicest details in the image.