Bunk bed and cot safety: the standards explained

Bunk beds and cots are the only furniture in a home with their own British and European safety standards, and the reason is entrapment: a gap that a child's body passes through but their head does not.

This guide sets out what BS EN 747 (bunk beds and high beds) and BS EN 716 (children's cots) require, written the way our fitters check it rather than the way the standard is drafted.

The single most common bunk fault we are called to correct is a guard rail that sits too low once the mattress is in. The standard measures the rail height above the top of the mattress, not above the bed base.

That means the mattress depth is part of the safety calculation. A deeper mattress than the maker allowed for silently converts a compliant bunk into a non-compliant one, which is why we check depth against the maker's stated maximum before signing off.

Both long sides of an upper bunk need protection, with only the ladder opening left clear, and that opening has its own maximum size.

Openings in the structure are controlled so that a small gap cannot trap a limb and a large gap cannot trap a head. It is the in-between sizes that are dangerous, which is why 'it looks fine' is not a test.

In practice we check the space between guard rail and mattress, the gaps between slats and rails, the ladder rung spacing and any decorative cut-outs in the headboard or footboard.

The ladder must be fixed at both ends so it cannot be lifted off or slide sideways under a climbing child. A ladder that hooks on and is not secured is the second most common fault we find.

Position matters too. An upper bunk should not sit under a pendant light, a shelf, a curtain pole or an openable window without a restrictor, and high sleepers usually need tying back to the wall — which is where the wall construction of the room becomes part of the build.

Manufacturers and safety bodies advise that the upper bunk of a bunk bed is not used by children under six. That is guidance rather than law, but it is written into the instructions of nearly every bunk sold in the UK, and ignoring it undermines any claim if something goes wrong.

In a let property, the same instructions form part of the furniture's safety information, so a landlord who has the bunk assembled correctly and photographed has evidence the guidance was followed.

BS EN 716 governs bar spacing, the depth from the mattress surface to the top of the cot side, and the mattress fit — the gap around the mattress edge should be small enough that a baby cannot become wedged in it.

Cots have two or three base heights. The highest is for a newborn who cannot sit up; the base must drop as the child grows, and the lowest setting is used once they can stand. We set the height to the age at build and tell you when it needs to change.

Cot-bed conversions use the manufacturer's own kit. A homemade conversion or a mixed set of parts from two cots is outside the standard entirely.

Every bolt torqued in sequence and the frame checked square, because a racked frame opens gaps that were compliant when the parts were flat on the floor.

Guard-rail height measured above the mattress in place, ladder fixings secured at both ends, gaps checked, and the maker's instruction booklet left with you rather than in the recycling — it carries the mattress depth limit you will need if you replace the mattress later.

Ceiling height is the first check. Measure floor to ceiling, subtract the top-bunk mattress height and the guard rail, and leave enough clear space above for a child to sit up without hitting the ceiling — roughly 750mm is the practical minimum most families are comfortable with.

Then check the light fitting, the smoke alarm and any sloping ceiling in the swing of the ladder. A pendant light directly over the top bunk is the most common reason a bunk has to be repositioned after delivery, and repositioning changes which side the ladder can go.

Finally, measure the route in. Bunk side panels are long and rigid; a stair with a half-landing turn sets a hard limit that the product page will not tell you about.

Every compliant bunk carries a maximum mattress depth, printed in the instructions and often stamped on the upper frame. The guard rail height is measured from the top of the mattress, so a deeper replacement mattress lowers the effective rail and takes a compliant bed out of the standard without a single bolt changing.

This is why we leave the maker's booklet with you instead of putting it in the recycling. When the mattress is replaced in three years, that number is the only thing standing between a safe bed and an unsafe one.

The same logic applies to mattress toppers on the top bunk: a 70mm topper is 70mm off the guard rail.

Bunks work loose because children move. Re-check the rail bolts, the ladder fixings at both ends and the guard-rail screws after the first month, then every six months. A spanner turn takes five minutes.

Look for the early signs between checks: a new creak under movement, a visible gap opening at a joint, or a ladder that shifts sideways when weight goes on the bottom rung. Each one means a fixing has backed off, not that the bed has failed.

A second-hand bunk without its instructions, without its original fixings or with drilled-out holes should not be rebuilt for a child. Replacement bolts of the wrong grade are a common and invisible fault, and the guard-rail height cannot be verified against a booklet you do not have.

Cots are stricter again. Drop-side cots, cots with damaged or repainted bars, and mixed sets of parts from two cots fall outside BS EN 716. We will build a second-hand cot only where the parts are complete, original and undamaged, and we will say so on the day if they are not.