Cot or cot bed in the parents' bedroom for the first six months?

What do NHS and the Lullaby Trust actually ask for?

The official line is about where the baby sleeps, not which shop label is on the frame. NHS guidance on sudden infant death syndrome (SIDS) says to place your baby in a separate cot or Moses basket in the same room as you for every sleep for at least the first 6 months. The Lullaby Trust safer-sleep overview uses the same six-month room-share and names a cot or Moses basket as the separate sleep space.

Neither page says a cot bed is required, and neither page says a standard cot is the better product. A cot bed is still a cot while the sides are on. The six-month rule is room-sharing in the parents' bedroom (or whichever room you sleep in), day and night, with the baby on their back on a firm, flat mattress in a clear sleep space.

The Lullaby Trust's room-sharing page adds that you can still leave the room to make a drink or go to the toilet. The point is that, for most of the sleep, you are close by — not that the furniture must be a converting cot bed.

How much floor does a cot bed take beside a UK double?

Which? (updated 19 September 2025) puts most cots at about 120 cm long by 60 cm wide and most cot beds at about 140 cm by 70 cm. High-street UK doubles use a 135 × 190 cm mattress. The comparison that matters in the parents' bedroom is that extra 10 cm of width, plus the walkway you still need to reach the baby and your own bed.

If you stand the cot bed along the long side of the double, you need roughly 135 + 70 cm of furniture width before anyone walks past. If you stand it across the foot of the bed, the 140 cm frame is slightly longer than the 135 cm mattress is wide, so it will stick out unless the bed has a wide footboard gap. A 120 × 60 cm cot is the tighter fit in both layouts.

Will a 140 × 70 cm cot bed even fit in a typical UK bedroom?

Which? tells shoppers to check that the cot bed fits in the bedroom where the baby is meant to sleep for the first six months, not only in a future nursery. Terrace and flat bedrooms often fail that check before they fail a furniture review. Do the tape-measure pass before you order.

1. 1
   Measure the wall you will use Note the clear length and width after wardrobes, radiators, windows and the door swing. A 140 cm cot bed needs a wall run longer than the frame plus any skirting or pipes.
2. 2
   Park the adult bed on paper first Sketch the 135 × 190 cm double (or your actual mattress) and the cot or cot bed to scale. Leave a walkway you can use at 3am without climbing over the frame.
3. 3
   Mark the official keep-clear list The Lullaby Trust says to keep the sleep space away from radiators, direct sunlight, blind cords and other hazards. A cot bed that only fits under a window or against a radiator is the wrong answer to the six-month rule.
4. 4
   Decide what happens after six months If the cot bed only fits the nursery, you still need a separate sleep space that fits the parents' room for the first six months — a smaller cot, a Moses basket or a travel cot used as a room-share space, following the same clear-cot rules.

What do I gain later if I start with a cot bed?

A cot bed's selling point is conversion, not a different safer-sleep rule. Which? describes a cot bed as a cot with removable sides and an end panel that becomes a toddler-sized / junior bed, and says many last until a child is seven or eight, depending on weight and wear. A standard cot does not convert; you buy a bed later.

• Space now versus space later. The 70 cm width is the cost of that later conversion while you are still room-sharing.
• Mattress size. A cot-bed mattress is the larger 140 × 70 cm size. It must still fit with no gaps and stay firm, flat and waterproof — the same Lullaby Trust checks as a cot mattress.
• Drop sides and drawers. These change how you lift the baby or store nappies. They do not change NHS room-share wording. Drop-side mechanisms still have to meet the cot standard the maker cites (Lullaby Trust lists BS EN 716-1:2017 for cots).

If the parents' bedroom cannot take 70 cm plus a walkway, starting with a 120 × 60 cm cot (or a Moses basket, then a cot) is the layout that matches the six-month advice. You can still move a cot bed into a larger room later. That is a furniture plan, not a safer-sleep ranking.

Does choosing a cot bed change safer-sleep rules?

No. Official pages apply the same sleep-space rules to a cot, a cot bed with the sides on, a Moses basket or a travel cot: baby on their back; own clear, flat, firm, waterproof surface; nothing that can cover the face; same room as you for at least six months. The Lullaby Trust's clear-cot list still rules out pillows, duvets, cot bumpers, soft toys, weighted or bulky bedding, and pods or nests.

A bedside crib with one open side is a different product (Lullaby Trust points to BS EN 1130:2019 from 2020). It can sit against the adult bed for room-sharing, but it is not a cot bed and it is not a reason to skip the six-month same-room line.

In shortPick the frame that fits the parents' bedroom for six months without blocking radiators, cords or the walkway. A 140 × 70 cm cot bed buys later conversion if that width exists; a 120 × 60 cm cot is the smaller room-share footprint. Official pages do not treat one as the safer product.