Bunk Bed Buying Guide: Sizes, Safety and Age

A bunk bed sleeps two children in the floor space of one. In a shared room, nothing else comes close. But there are more decisions here than in any other kind of bed, and one rule that isn't negotiable. This guide covers both: the age rule, the measurements to take, the types of bunk bed, and what to check before you order.

The rule: the top bunk is for 6 and over

The bottom bunk is different. There's no equivalent age restriction, so a bunk bed works well for siblings of different ages: the older child on top, the younger one underneath. It's the most common arrangement we sell into. When the younger one turns 6 and wants to swap, a detachable bunk gives you more options.

The two measurements

• Headroom above the top bunk. The child on top needs to sit up comfortably. Measure from where the top-bunk mattress will be up to the ceiling, directly above where the bed will stand: a younger child needs roughly 70cm, and a teenager 80 to 90cm. Sloping ceilings and loft conversions are where this catches people out.
• Mattress depth on the top bunk. Usually 15 or 16cm at most. Guard rails are designed to sit a set height above the mattress, and most high-street singles are 20cm or deeper, which takes 5cm or more off the rail's effective height. Our bunk bed mattresses are made at 15cm for this reason.

If an older child or an adult will use the bed, ask us and we'll confirm what the manufacturer says about it.

Which type of bunk bed?

The one that lasts longest

Detachable

Splits into two single beds. Worth it if there's any chance the children will want their own rooms, or the younger one will want the top bunk at 6. It often costs little extra, and it's the feature that most extends a bunk bed's life.

Alfie, Ashby, or all detachable bunks

Sleeps three

With a trundle

A third bed on a low frame that slides away underneath, so three children sleep in the footprint of one bed. The version most families choose once sleepovers start. The trundle takes a slimmer mattress, around 10cm.

Burford, Kew staircase bunk, or all bunks with trundles

One piece of furniture instead of three

With storage

Drawers, shelves or a wardrobe built into the frame, which matters more in a shared room than anywhere else.

Belgravia, Nook, or all bunks with storage

For lower ceilings

Low bunk

A lower overall height, which helps with low or sloping ceilings. The 6+ rule for the top bunk still applies.

Nyla, or our guide to low bunk beds

A double underneath

Double bunk

A full double on the bottom and a single on top: room for a parent at bedtime, two younger children sharing the bottom, or guests.

Burford family bunk, or our double bunk guide

Three children, or a small room

Triple sleepers and shorty bunks

Triple sleepers fit three children in one room, where ceiling height becomes the limit rather than floor space. Shorty bunks take 75 x 175cm mattresses for a smaller room.

All triple sleepers, or the Tarn shorty bunk, which takes 70 x 160cm mattresses

Ladder or stairs?

A ladder takes up almost no floor space and usually costs less. Stairs are easier to climb, especially at night, and the steps often have drawers built in, so the storage comes with them. The trade-off is footprint: stairs add noticeably to the bed's length or width, so measure before you commit.

On any bunk, check which side the ladder or stairs attach, and whether they can be swapped to the other side. Some are fixed, and finding out after assembly is an expensive lesson.

You'll need two mattresses, or three

The most commonly forgotten part of buying a bunk bed, and the one that ruins delivery day.

• Standard bunk: two mattresses, the top one within the stated maximum depth.
• Bunk with a trundle: three, with a slimmer trundle mattress of around 10cm.
• Shorty bunk: two shorty mattresses, 75 x 175cm, not standard singles.
• Double bunk: a double for the bottom and a single for the top, plus a trundle mattress if fitted.

Order them with the bed. Our bunk bed mattress guide covers sizes and depths, and our kids' bed size guide covers every size.

When a bunk bed isn't the answer

• A low or sloping ceiling. Look at a low bunk, or two separate beds.
• Both children are under 6. Only the bottom bunk could be used for now, so two floor-level beds usually make more sense.
• Sleepwalking, or difficulties with balance or coordination.
• You'll be changing the sheets. Making the top bunk is awkward, and it's the thing parents most often say they hadn't considered.
• A big age gap. A teenager and a toddler rarely share a bunk bed happily for long.

Bunk bed safety in use

There's more on our safety advice page.

Before you order

• Measure the headroom above where the bed will stand.
• Measure the floor space, including the ladder or stairs.
• Check whether it's detachable, if you might want two separate beds later.
• Check the maximum mattress depth on the product page.
• Count the mattresses: two, or three with a trundle.
• Plan the assembly. Allow two adults and a few hours. Assembly is available on many of our beds; see beds with assembly.

Common questions