Harrison Spinks Westminster 15750 Super King Mattress
The Harrison Spinks Westminster 15750 is a natural-fill pocket sprung mattress with a listed 15,750 springs, which means support that responds to small shifts in position rather than pushing back in one broad zone.
- Keeps warm sleepers cool & dry
- Minimises partner disturbance
- Traceable British wool fillings
£2,849
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Harrison Spinks Westminster 15750 Mattress
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Mattress details
Mattress
Harrison Spinks Westminster 15750 Mattress
Size
Firmness
Medium Firm
Construction
Pocket Spring
Wool
Natural
Depth (cm)
32
Layers
4
Layer Details
Top comfort layer
An Egyptian cotton and flax blend that wicks away excess moisture, which means you're less likely to wake up feeling clammy. Both are naturally breathable fibres.
Mid comfort layer
Egyptian cotton, kapok and alpaca wool work together to regulate temperature. In practice that means a cooler feel in summer and a cosier one in winter.
Viscose wool layer
A viscose wool blend derived from the wood pulp of eucalyptus, beech and pine trees. It helps regulate temperature and promotes airflow through the mattress.
Spring system
At the centre sits a layer of Cortec pocket springs with four layers of micro springs and micro ultra springs. Layered springs like these respond to your body in finer detail than a single spring unit, so support feels more tailored.
Layer details from mattressnextday.co.uk product page, September 2026.
Key benefits
- 90cm of space each: Two people sharing get 90cm each, which means a partner who turns over frequently becomes far easier to sleep through.
- Distance plus localised springs: The Cortec pocket spring system already limits motion transfer, and at this width most movement happens too far away to feel at all.
- Room for night-time visitors: Children who wander in during the small hours, or a dog with established habits, can be absorbed without anyone ending up clinging to an edge.
- Breathable at scale: The cotton, alpaca wool and kapok fillings keep airflow moving, useful when three or four bodies end up sharing one surface.
- A better fit for larger rooms: In a big master bedroom or period property a UK king can look undersized, and the extra 30cm of width fills the space properly.
This size suits you if...
You share the bed every night and want the most separation you can buy, your partner is genuinely restless and distance will do more for your sleep than any comfort layer, or children and pets regularly join you and everyone still needs their own share. It also suits a large master bedroom where a smaller size would leave the room feeling half furnished.
Consider another size if...
Your bedroom falls short of the 3m x 2.9m we suggest as a minimum for a UK super king. We'd recommend the UK king instead: it's 30cm narrower but the same length, and needs a room of at least 2.7m x 2.9m.
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FAQ's
What size room do I need for the Westminster 15750 super king?
The mattress itself measures 180 x 200cm. We suggest a room of at least 3m x 2.9m, and around 3.5m x 3.2m feels more comfortable, leaving space to walk round both sides and open wardrobe doors. These figures are our own guidance rather than Harrison Spinks', so measure your room before ordering.
How much space do two people get on a super king?
90cm each for two people sharing, the same width per person as a UK single. On the Westminster 15750 that pairs well with the Cortec pocket springs, which respond to movement locally, so between the width and the spring system a fidgeting partner is unlikely to wake you.
Is the Westminster 15750 worth buying in super king rather than king?
If your room takes it, usually yes. The UK super king is 30cm wider than the UK king and the same length, and that extra width is what makes sharing with children or pets workable. If the room is under 3m x 2.9m, the UK king is the sensible choice.
Is a super king big enough to share with children?
It's the size best suited to it. At 180cm wide there's room for a child between two adults without either parent being pushed to the edge, and the breathable natural fillings help when extra bodies raise the temperature. It won't feel spacious every night, but nothing smaller manages it as well.
Will the super king fit through my doors and up the stairs?
This is the size where access bites. A 180 x 200cm mattress at 32cm deep is awkward on tight landings and around door swings, so measure the route as carefully as the room. Harrison Spinks doesn't publish a weight for this mattress, so plan for two people to move it.