Key points
- Guarding heights are 900mm or 1100mm in most buildings, depending on use and location. Use 800mm in front of fixed seating and for opening windows.
- Loads are given as a line load at the top, a distributed load on the infill and a point load on the infill. Each is checked separately; they are not added together.
- Where children under five may be present, a 100mm sphere must not pass through any opening, and the guarding should not be easy to climb.
- Loads rise sharply where crowds can gather. Bars, malls and assembly areas take 3.0 kN/m at the top, against 0.74 kN/m for an office.
When guarding is needed
Approved Document K says guarding is needed where there is a drop of more than 600mm in a dwelling. In other buildings, it is needed on stairs and ramps with two or more risers. Guarding is also needed at the edges of floors, balconies, galleries and roofs that people can reach.
Minimum guarding heights
From Approved Document K, Diagram 3.1. Heights are measured from the floor, or from the pitch line on stairs.
| Building and location | Minimum height |
|---|---|
| Single-family dwelling: stairs, landings, ramps, edges of internal floors | 900mm |
| Single-family dwelling: external balconies (including Juliet balconies) and edges of roofs | 1100mm |
| Residential (other), institutional, educational, office and public buildings: flights | 900mm |
| Residential (other), institutional, educational, office and public buildings: everywhere else | 1100mm |
| Retail: flights / everywhere else | 900mm / 1100mm |
| Assembly: within 530mm in front of fixed seating | 800mm |
| Assembly: flights / everywhere else | 900mm / 1100mm |
| Opening windows (guarding to glazing) | 800mm |
Design loads
Approved Document K points to BS EN 1991-1-1 with its UK National Annex and PD 6688-1-1 for loads, and to BS 6180 for barrier design. The figures below are characteristic (unfactored) loads from Table NA.8 of the National Annex. The same values appear in BS 6180:2011.
| Type of occupancy (summary) | Line load at top (kN/m) | UDL on infill (kN/m²) | Point load on infill (kN) |
|---|---|---|---|
| Areas within a single dwelling (not external balconies or roof edges) | 0.36 | 0.5 | 0.25 |
| Other residential, including balconies, Juliet balconies and roof edges | 0.74 | 1.0 | 0.5 |
| Offices and classrooms not susceptible to overcrowding | 0.74 | 1.0 | 0.5 |
| Restaurants, cafés, retail, and areas with fixed seating | 1.5 | 1.5 | 1.5 |
| Theatres, cinemas, bars, shopping malls and assembly areas susceptible to crowds | 3.0 | 1.5 | 1.5 |
| Light access stairs and gangways not more than 600mm wide | 0.22 | – | – |
This is a summary. The full table splits occupancies more finely and has further notes. Check the current editions for the exact category, and add wind load on external barriers.
Where children may be present
- No opening in the guarding should let a 100mm sphere pass through.
- Avoid horizontal rails and other features that make it easy to climb.
- These rules apply to dwellings and to any building likely to be used by children under five.
Glass in barriers
Glass used as guarding also has to meet the impact-safety rules in Approved Document K, Section 5. It must also stay safe after breakage. See our glass balustrade specification guide.
Checklist for a balustrade specification
- Building type, and which load category applies to each area
- Height to the top of the guarding, and how it is measured
- Rules for openings and climbability if children under five may be present
- Wind exposure for external barriers
- Fixing substrate, and who designs the fixings and the structure they fix to
- Handrail heights and extensions on accessible routes (Approved Document M)
Sources
- Approved Document K: protection from falling, collision and impact (2013 edition, GOV.UK)
- BS 6180:2011 Barriers in and about buildings. Code of practice (BSI)
- BS EN 1991-1-1 and UK National Annex, Table NA.8 (BSI)
- PD 6688-1-1 (BSI)
General guidance only, not design advice for a specific project. Check the current edition of each document.