Hypnos Alcester Ortho Extra Mattress
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Mattress
Hypnos Alcester Ortho Extra Mattress
Size
Firmness
Firm
Construction
Pocket Spring
Wool
Orthopaedic
Natural
Depth (cm)
27
Layers
4
Layer Details
Damask cover
A finely woven, durable fabric that feels soft to the touch. It doesn't retain heat, which means it stays cooler against you through the night.
Cotton
Breathable cotton fibres that wick away moisture. In practice that keeps you dry and cool rather than clammy.
Solotex™
A filling engineered from recycled plastic, so it's an eco-friendlier choice. It's extremely durable and cuddles body contours for a slightly softer feel over the firm springs.
Pocket Springs
1,200 ReActivePro 6-turn pocket springs with tighter spring resistance. That means a more supportive surface that still adapts to your unique shape, weight and movement.
Layer details from mattressonline.co.uk product page, September 2026.
- Firm support with space to move: The 1,200 ReActivePro 6-turn pocket springs keep the whole 120cm width evenly supportive, so you can shift position at night without finding a soft edge.
- Room for one to stretch: At 30cm wider than the UK single, this size suits a back or front sleeper who has outgrown a single but doesn't need a full double.
- Fits where a double won't: It's 15cm narrower than the UK double, which can be the difference between a door that clears the bed frame and one that doesn't.
- Cool across a compact room: The damask cover and breathable cotton fillings resist heat build-up, useful in smaller rooms where warm air has nowhere to go.
- Flippable for a spare room: Because it can be rotated and flipped, it wears evenly even with the irregular use a guest bedroom gets.
This size suits you if...
You're a solo adult who sleeps on your back or front, prefers a firm feel, and wants more width than a UK single without giving up floor space, or you're furnishing a box room, loft conversion or guest bedroom where a 4ft frame fits and a 4ft 6in one wouldn't. It also suits a spare room where couples stay occasionally rather than every night.
Consider another size if...
You share the bed every night, because 120cm gets tight for two adults on a firm mattress with little sink-in. We'd recommend the UK double instead, which is 15cm wider; allow a room of at least 2.6m x 2.8m.
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Is a small double big enough for a firm mattress like the Hypnos Alcester Ortho Extra?
For one adult, comfortably. The firm pocket spring surface stays consistent across the full 120 x 190cm, so a solo sleeper has real room to change position. For two people sharing nightly it's a squeeze, since a firm feel means you lie on the surface rather than sinking in, and personal space matters more.
Can a couple share the Hypnos Alcester Ortho Extra in a small double?
For occasional nights, yes, which makes this size a sensible guest room choice. The tighter spring resistance limits motion transfer between you, so one person turning over is less disruptive. Every night is a different matter: at 120cm wide most couples will want the UK double, which is 15cm wider.
What room size do I need for a small double Hypnos Alcester Ortho Extra?
We suggest at least 2.4m x 2.8m, which is our guidance rather than the manufacturer's. That leaves walking room on at least one side and space for a wardrobe door to open. In a loft conversion, check where the ceiling height sits over the bed's position before committing to any size.
Is the small double a good size for a teenager?
Often, yes. It's 30cm wider than the UK single at the same length, so a teenager who has outgrown a single gains genuine width without losing much floor space. The firm feel suits growing back and front sleepers, though a lightweight side sleeper may find this mattress presses on shoulders and hips.
Should I choose the small double or size up to the UK double?
It usually comes down to the room. The UK small double fits spaces where we'd suggest at least 2.4m x 2.8m; the UK double needs at least 2.6m x 2.8m. If you sleep alone, the small double is ample. If a partner stays most nights, the extra 15cm of the UK double is money well spent.