Harrison Spinks Westminster 15750 Mattress
Save with the previous model
Some retailers still sell the earlier version of this mattress. These is where it costs less than the current model's best price.
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.
- Real space for a solo sleeper: At 30cm wider than the UK single, it gives one adult genuine room to shift position without meeting the edge.
- Fits rooms a double crowds: Being 15cm narrower than the UK double, it can be the size that keeps a walkway clear in a box room or studio.
- Localised support you'll actually notice alone: The Cortec pocket springs respond to small shifts in position, so a solo sleeper moving around at night feels support follow them rather than one broad push-back.
- Breathable fibres in a compact room: Egyptian cotton, alpaca wool and kapok wick moisture and let air move, useful in smaller rooms where warmth can build overnight.
- Standard 4ft sizing: The small double is a standard UK size, so frames and fitted sheets are straightforward to find.
This size suits you if...
You sleep alone and have outgrown a single but your room can't take a full double, or you're furnishing a guest room where couples stay occasionally rather than nightly, or you're downsizing and the bed has to fit the new room rather than the old one. Allow at least 2.4m x 2.8m of floor space, our suggestion for a small double, before committing.
Consider another size if...
You share the bed every night, in which case 120cm of width will feel tight for two on a mattress you'll own for years. We'd recommend the UK double instead; allow at least 2.6m x 2.8m for it.
Similar Mattresses in This Price Range
Did you know? On Mattress Unboxed we have over 1,000 different mattresses to suit all types of sleepers. View all mattresses.
Is a small double big enough for the Westminster 15750 to suit a couple?
For occasional nights, yes. The pocket spring system limits motion transfer, which helps when two people share a narrower surface. For every night, though, 120cm across is a squeeze for two adults, and we'd point regular sharers at the UK double, which is 15cm wider.
What room size do I need for a small double Westminster 15750?
We suggest allowing at least 2.4m x 2.8m. That gives you space to walk around the bed and open drawers or doors without shuffling sideways. In a loft conversion or box room, measure the usable floor rather than the full footprint, since sloping ceilings eat into where a bed can actually sit.
How much wider is the small double than a single?
The UK small double is 30cm wider than the UK single, and the two are the same length at 190cm. That extra width is the whole point of the size: a teenager or adult who has outgrown a single gets real stretching room without the jump to a full double frame.
Will the Westminster 15750 in this size work in a guest room?
It's a sensible guest room choice if visiting couples stay for the odd weekend rather than living with you. The natural fillings breathe well in rooms that sit unused between visits, and the 4ft width leaves more floor space than a double, which matters in a small second bedroom.
Where can I buy the small double Westminster 15750?
Compare the retailers listed on this page. The prices shown here are updated as retailers change them, so check the live table rather than relying on a figure you saw elsewhere. Stock of this size can move around, so it's worth checking back if it isn't showing today.