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.
- A shared size that fits real rooms: We suggest allowing at least 2.6m x 2.8m, which most UK second bedrooms and terrace bedrooms can manage with wardrobe and drawers still in place.
- Firm support that holds its shape across the width: The 1,200 ReActivePro 6-turn pocket springs keep resistance consistent, so a heavier partner sinking in shouldn't tilt your side of the bed.
- Room for bedside tables on both sides: At 135cm wide, the UK double usually leaves space either side for a table and lamp, something a UK king often takes away in smaller rooms.
- Cool for two sharing: Two bodies mean more heat, and the damask cover with breathable cotton wicks moisture away rather than letting the bed turn clammy.
- Flippable, which suits shared use: Because the mattress can be rotated and flipped, a couple with different weights can even out wear rather than developing two distinct dips.
This size suits you if...
You share the bed every night and your room sits comfortably above our suggested 2.6m x 2.8m minimum, you both prefer a firm feel and sleep mostly on your back or front, or you sleep alone and want space to spread out, perhaps with a dog or cat claiming the bottom corner. It also suits a guest room that hosts visiting couples.
Consider another size if...
You share with a partner and find 67.5cm each for two people sharing a little tight, especially with a firm surface you sink into less. If your room allows at least 2.7m x 2.9m, we'd recommend the UK king instead, which is 15cm wider and 10cm longer.
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Is a UK double Hypnos Alcester Ortho Extra big enough for two adults?
It works for most couples, with one caveat. The UK double gives 67.5cm each for two people sharing, and because this is a firm mattress you lie on the surface rather than sinking into it, so you may notice a partner's movement at the edges of your space more than on a softer bed. Back and front sleepers who don't sprawl will be fine.
Will the Hypnos Alcester Ortho Extra double fit up a narrow staircase?
At 135 x 190cm and 27cm deep, the UK double is one of the more manageable sizes to move, but a firm pocket spring mattress doesn't bend the way foam does. Measure turns on older terrace stairs and tight new build landings before ordering, and check the retailer's delivery guidance on access.
Should I get the double or the small double for one person?
For a solo sleeper the UK double is the more generous choice: it's 15cm wider than the UK small double, and both are the same length. If your room is the limiting factor, we suggest at least 2.4m x 2.8m for the UK small double against 2.6m x 2.8m for the UK double. Solo sleepers who like to spread out rarely regret the extra width.
What room size do I need for this mattress in a UK double?
Allow at least 2.6m x 2.8m, which is our own guidance rather than the manufacturer's. That leaves walking room and, in most layouts, space for bedside tables on both sides. If you're furnishing a first flat and need a wardrobe and drawers in the same room, sketch the layout first: the double usually works where a UK king wouldn't.
Where can I buy the Hypnos Alcester Ortho Extra in a UK double?
Availability for this size is shown in the live comparison table on this page, with prices updated as retailers change them. Stock and pricing can differ between sizes of the same mattress, so it's worth checking the table for the UK double specifically rather than assuming it matches what you've seen quoted for other sizes.