The short answer. Buy IKEA when price and speed matter most and your wall suits standard sizes: two sections of IVAR shelving in solid pine cost £106, and a pair of BILLY bookcases costs £110. Pay more for a made-to-measure modular system like Mestra when the wall is the awkward part, you want 18 mm birch plywood, and you plan to change the shelving rather than replace it. Our two-bay open shelving layout is £1,496.71 at the time of writing (October 2026), made to order in 5 to 10 weeks.
IKEA is far cheaper and far quicker. That gap is not small, and for a lot of rooms it settles the question. This guide sets out what the extra money buys, where it buys nothing, and how to tell which side of the line your wall is on.
We checked every IKEA price, size, and material here on ikea.com/gb on 6 October 2026. IKEA changes prices and ranges often, so check the product page before you buy.
IKEA’s shelving lines, in brief
The IKEA IVAR shelving system
IVAR is untreated solid pine: side units with shelves that sit between them. Shelves are 42 or 83 cm wide and 30 or 50 cm deep. Side units come in 124, 179, and 226 cm heights. IKEA lists the 83 cm shelf as 1.8 cm thick with a 35 kg maximum load. IVAR stands on the floor and must be anchored to the wall. IKEA suggests oiling or waxing the pine, and says you can stain or paint it.
The BILLY bookcase
BILLY is particleboard and fibreboard with a paper foil surface and plastic edging. The standard unit is 80 cm wide, 28 cm deep, and 202 cm tall, with one fixed and four adjustable shelves, for £55. There are 40 cm wide units, 39 cm deep versions, a 106 cm tall version, and height extension units that take it to 237 cm. IKEA rates each 80 cm shelf at 30 kg and each 40 cm shelf at 14 kg. BILLY must be anchored to the wall.
The KALLAX shelving unit
KALLAX is a grid of cubes rather than a run of shelves. It is particleboard and fibreboard with a honeycomb paper filling, finished in acrylic paint, and 39 cm deep. Sizes run from 42 x 42 cm to 182 x 182 cm. The 147 x 147 cm unit, with sixteen cubes, is £99 at the time of writing; IKEA marks that as a new lower price, down from £115. Each shelf takes up to 13 kg. Inserts add doors and drawers. KALLAX must be anchored to the wall, and some sizes can also be hung on it.
IKEA and Mestra side by side
The shelving
| IKEA IVAR | IKEA BILLY | IKEA KALLAX | Mestra | |
|---|---|---|---|---|
| Material | Untreated solid pine, steel cross-brace | Particleboard and fibreboard, paper foil, plastic edging | Particleboard and fibreboard, honeycomb paper filling, acrylic paint | 18 mm Baltic birch plywood throughout |
| How it fits the wall | Stands on the floor; must be anchored to the wall | Stands on the floor; must be anchored to the wall | Stands on the floor and must be anchored; some sizes can hang on the wall | Rails screw to the wall; shelves and cabinets hang on pins in the rails |
| Widths | Shelves 42 or 83 cm | Units 40 or 80 cm | 42 to 182 cm, in cube steps | Any bay from 500 to 800 mm, in 1 mm steps. Other widths by quote |
| Heights | 124, 179, or 226 cm | 106 or 202 cm; 237 cm with an extension unit | 42 to 182 cm | 900 mm, or 1800 mm with two rails. Some layouts use a 395 mm rail |
| Depths | 30 or 50 cm | 28 or 39 cm | 39 cm | Shelves 220 or 300 mm; 360 mm between bookends. Cabinets 360 mm |
| Finishes | Raw pine, to oil, wax, stain, or paint yourself | White, oak effect, brown walnut effect, black oak effect, or blue | White, black-brown, white stained oak effect, grey wood effect, brown walnut effect, or high-gloss white | 13 hardwax oil colours. Melamine by quote |
| Example wall | 2 sections, 134 x 30 x 179 cm, 10 shelves: £106 | 2 bookcases, 160 x 28 x 202 cm, 10 shelves: £110 | 147 x 147 cm, 16 cubes: £99 | 2 bays, 1234 x 1800 x 254 mm, 12 shelves: £1,496.71 |
Buying and aftercare
| IKEA (IVAR, BILLY, KALLAX) | Mestra | |
|---|---|---|
| Lead time | Take it home from a store if it is in stock, or standard delivery in 5 to 30 days. Express delivery costs extra | 5 to 10 weeks from order, made in our Norfolk workshop |
| Delivery | Charged by weight, from £5. Any box over 25 kg puts the order in the £40 standard band | Included to mainland UK addresses. Islands and remote addresses may cost more, so ask first |
| Assembly | Build it yourself, or book Taskrabbit through IKEA from £33. Taskers secure items to the wall at no extra cost | You fit it yourself with our manual. Fitting tools come in the box: an alignment spacer with a built-in level, a PZ2 driver bit, and a drill bit for your wall. You bring the drill |
| Wall fixings | IKEA tells you to use screws and plugs that suit your wall | Fixings come in the box, matched to your wall. We check your wall type with you before we send them |
| Guarantee | These lines are not on IKEA UK’s guarantees page. Your statutory rights still apply | Ten-year warranty for defects in materials and workmanship, alongside your statutory rights |
| Returns | 365 days. Opened or assembled items are refunded to a refund card | 60-day Home Trial. We collect at no cost; parts need to be in resalable condition |
What the price gap buys
Start with the honest number. A pair of BILLY bookcases is £110. Each one ships in a single 36.85 kg box, which puts the order in IKEA’s £40 standard delivery band, so call it £150 delivered. Our two-bay open shelving layout, a similar size, is £1,496.71 with delivery to mainland UK included. That is roughly ten times as much.
The extra money does not buy more shelf space. Two BILLYs give you ten shelves across 160 cm. Our two bays give you twelve shelves across 1234 mm, and at 220 mm our standard shelves are shallower than BILLY’s 28 cm.
What it does buy:
- A width set to your wall. Each bay can be any width from 500 to 800 mm, in 1 mm steps.
- Real birch plywood. Every shelf, rail, and cabinet is 18 mm Baltic birch plywood, with the layered edges on show.
- A finish you can repair. The hardwax oil soaks into the birch, and worn spots can be re-oiled.
- Parts that move. Shelves and cabinets hang on pins in the rails. Move a shelf, swap a cupboard for drawers, or add a bay later. You can buy single replacement parts, so a damaged shelf or rail is a part, not a new unit.
- Local making and a long warranty. We make every order in Norfolk, and it carries a ten-year warranty.
If none of that matters for the room, the gap is hard to justify. A rented flat, a child’s room you will redo in a few years, or a garage are good places to spend £110, not £1,500.
Our pre-configured layouts start from £746.94 at the time of writing (October 2026), and one bay of open shelving is from £828.34. The configurator shows the live price as you build your own.
Materials and sagging
Any shelf bows if the load is too much for its span. Wood-based boards also deflect a little further under a load left on them for years. Engineers call that creep, and it applies to particleboard and plywood alike. What changes is how much load a shelf is rated for and how far it spans.
IKEA publishes a maximum load for each shelf:
