Stacking high is fine: our terms set no stacking limit, except that anything with a built-in battery must not be stacked at all. Height is the part to check. For indoor units we don't publish ceiling or door heights, and they vary between our sites and between floors, so before you book, measure your tallest item standing up, tell us the figure, and ask us to check it against the unit and its door. Then stack only as high as you can safely lift down, with heavy things at the bottom.
How high are the units?
Our unit sizes, from 10 sq ft to 300 sq ft, describe the floor. We list units by floor area (square feet and square metres). Sizes are approximate (clause 26), and for indoor units we don't publish length, width or height, so if a long or tall item has to fit, ring us on 0800 2545585 with its measurements before you book.
Clause 26 of our storage agreement says "Unit sizes are approximate", and that if you have exact requirements you must check with us before signing, "as, by signing, You agree to the actual size of the Unit". The same clause makes it your job to make sure the unit suits what you're storing, and advises you to inspect it first. So if you're bringing a tall wardrobe, a grandfather clock or a shelving system, measure it standing up (feet, cornice and all) and ask us for the height of the unit you're booking. Ask about the door opening as well, because that's the gap your tallest piece has to pass through. Our Box Shop sells a 5m tape measure for £3.49 if you need one.
Containers: a known shape
Our container storage page describes 160 sq ft containers, and our booking system (September 2026) lists 80 sq ft and 160 sq ft containers at Chipping Norton, 160 sq ft at Shipston-on-Stour and 320 sq ft (40ft x 8ft) at Warminster (see how big are our container units). The containers are listed as 20ft x 8ft (Chipping Norton and Shipston-on-Stour; 10ft x 8ft also listed at Chipping Norton) and 40ft x 8ft (Warminster); our pages don't say whether those are internal or external measurements. We don't publish their height, so ask us what height the container and its door give you. More on containers is on our container storage page.
Lincoln's restricted-height floor
Some units on the second floor at Lincoln are listed as restricted height; if height matters, ask us before you book. The Lincoln page has the site details.
Stacking high safely
Packing upward lets a smaller unit hold more, as long as every stack stays stable. The habits that keep it that way:
- Heaviest at the bottom, fragile on top. Solid, stable furniture, such as a wardrobe standing upright, can act as a wall to stack boxes against.
- Our own house-move packing guide suggests, as a working rule, no more than five boxes high unless the bottom boxes are rated for heavier loads. Never build a stack you can't take down without standing on something unstable.
- To see what stacking saves: a medium box (457 × 330mm) covers about 1.6 sq ft of floor and a large box (450 × 450mm) about 2.2 sq ft, so 50 large boxes stacked five high take up about 22 sq ft, before you leave an aisle to reach them.
- Strong boxes of the same size. Bags give no structure and stack badly.
- Keep weight off furniture that can't take it. Weight on top of chests of drawers and cabinets can squeeze the carcass and warp the drawer runners.
- Leave an aisle so you can reach the back without climbing.
That five-box rule means different heights depending on the box:
| Box (Box Shop) | Height of one box | Five high |
|---|---|---|
| Medium, 457 x 330 x 330mm, £3.50 | 330mm | about 1.65m (5ft 5in) |
| Large, 450 x 450 x 500mm, £4.50 | 500mm | about 2.5m (8ft 2in) |
Five large boxes puts the top one above your head, so keep the heaviest boxes low and only light ones up top. The Health and Safety Executive's guidance on lifting advises reducing lifts from floor level or above shoulder height, keeping the load close to your waist, and not lifting more than you can easily manage. For a long lift from floor to shoulder, it suggests resting the load halfway to change your grip. If you'll be in and out often, a small, sturdy step stool kept in the unit is safer than climbing on boxes or furniture.
The one firm rule in our terms: anything with a built-in battery (e-bikes, laptops, power tools) must not be stacked and needs air around it. See storing e-bikes and lithium batteries.
If you're storing stock, or your unit is upstairs
If you run a business from home and visit your unit often, keep the stock you pick most off the floor and below shoulder height, and put slow-moving lines up high, so the lifts you repeat are the easy ones.
Flat-pack and long cartons take a little thought. Our house-move packing guide suggests standing flat-packed furniture against the walls rather than leaving it flat on the floor, and our renovation packing guide says to stack horizontally only when an item has no vertical option. Where boxed stock has to lie flat, put the heaviest and largest cartons at the bottom on a level base, with smaller, lighter ones above.
If you want shelving, clause 22(d) of our terms says you must not "paint or make alterations to or attach anything to the internal or external surfaces of the Unit", and clause 22(f) rules out causing damage to it. So nothing fixed to the walls, floor or ceiling. The terms don't mention freestanding shelving or racking; our market traders guide says "Bring your own shelving if it helps", so keep any shelving free-standing, and ask us about anything large or heavy.
If your unit is on an upper floor, tall items also have to get there. At Chipping Norton our price list marks the mezzanine floor "No lift", so a tall or heavy piece is easier in a ground-floor unit. See ground-floor units, and for how much weight a unit's floor can take, weight limits in a storage unit.
Check the height, then book
If a height matters to you, call us on 0800 2545585 and ask for the height of the unit you're looking at, and its door. If you already know what fits, get a price online.
Related questions