Bookcase and alcove shelving plywood cut list: worked example

A 600 mm wide alcove shelving unit, 2200 mm tall with six shelves in 18 mm ply, needs two sheets of 18 mm plywood. A double alcove (two bays side by side) needs three sheets. The cut list and nesting layout are below.

Alcove built-ins are one of the most searched home improvement projects in the UK. The calculation is not complicated, but the details matter: shelf depth, the number of shelves, and whether the unit has a back panel all change the sheet count, sometimes by a full sheet.

The example unit

This guide uses a single alcove unit: 600 mm wide, 2200 mm tall, mixed shelf depths. The bottom four shelves are 300 mm deep for art books, storage boxes and larger volumes. The top two shelves are 200 mm deep for paperbacks and small items, which also helps the unit feel lighter visually and reduces the depth protruding into the room at high level.

All parts are cut from 18 mm birch or hardwood-faced plywood. Alcove built-ins are often painted, in which case cheaper structural ply with a hardwood face is fine. If the shelves will be left natural or oiled, birch ply gives a cleaner edge.

This example has no back panel: the alcove wall acts as the back, which is the standard approach for UK alcove shelving. If you want a back panel (for a freestanding bookcase or to conceal a poor wall), add one sheet of 6 mm ply to the order.

Parts list

The side panels run the full height of the unit. The top and each shelf fit between the sides, so their width is 600 minus 2 × 18 = 564 mm. There is no bottom panel: the lowest shelf sits at skirting-board height and the unit is fixed to the wall above the skirting, so the floor is the base.

The sides are 300 mm deep throughout, matching the deepest shelf. The shallow shelves at the top simply have less depth: they are the same width (564 mm) and thickness (18 mm) but only 200 mm front to back. This means one rip cut divides a 300 mm panel into a 200 mm shelf and a 100 mm offcut, which can be used for shelf-pin strips or shelf edge banding.

How the parts nest onto two sheets

All nine parts are 18 mm ply. Here is how they fit onto two standard 2440 × 1220 mm sheets.

Sheet 1:

• Side panel A: 2200 × 300 mm. Place it along the sheet length. Uses 2200 mm of 2440 mm length, and 300 mm of 1220 mm width.
• Side panel B: 2200 × 300 mm. Placed alongside A: 300 + 3 + 300 = 603 mm of the 1220 mm width used. Remaining strip: 617 mm wide, 2440 mm long.
• Top panel: 564 × 300 mm. Cut from the 617 mm strip. Uses 564 mm of the 2440 mm strip length and 300 mm of the 617 mm width.
• Two deep shelves: each 564 × 300 mm. Placed end-to-end next to the top panel in the same strip: 564 + 3 + 564 + 3 + 564 = 1698 mm total along the strip. With the top panel that is 564 + 3 + 564 + 3 + 564 + 3 + 564 = 2262 mm, which exceeds the 2440 mm strip by only 178 mm, so three 564 mm parts fit in one pass (3 × 564 + 2 × 3 = 1698 mm) alongside the top. Together all four fit: 4 × 564 + 3 × 3 = 2265 mm, within the 2440 mm sheet length.

Sheet 1 gives: both sides, the top panel, and three deep shelves. Offcut: a small strip at the end and the remaining 317 mm-wide strip from the far side.

Sheet 2:

• One deep shelf: 564 × 300 mm. Along the sheet length.
• Two shallow shelves: 564 × 200 mm each. Placed alongside the deep shelf: 300 + 3 + 200 + 3 + 200 = 706 mm of the 1220 mm width. All three shelves fit in a single 564 mm row.

Sheet 2 gives: one deep shelf and both shallow shelves. The remaining area of sheet 2 (roughly 1876 mm × 514 mm, plus the lower half of the sheet) is generous offcut.

Total: 2 sheets of 18 mm ply for the full unit.

Mixing shelf depths: why it works efficiently here

Two different shelf depths can look like it complicates the cut list, but in this case it helps. The side panels are 300 mm deep, and the 200 mm shallow shelves are just a narrower rip from the same 300 mm stock. Every part shares a common 300 mm or 200 mm dimension, so strips cut from the side panel layout on sheet 1 can supply shelf material directly.

If all six shelves were 300 mm deep, the total part count and area would be slightly larger and the nesting slightly tighter. It would still fit on two sheets, but with less offcut margin. The mixed-depth layout is more efficient, not less.

Shelf bay heights

The six shelves and one top panel divide the 2200 mm internal height. Accounting for the top panel (18 mm) and six shelves (each 18 mm), the clear internal height for books is 2200 minus (7 × 18) = 2200 minus 126 = 2074 mm, split across seven bays.

A suggested layout, with the bottom two bays taller for oversized books:

Bays 1 and 2 at 330 mm clear height fit a standard UK A4 hardback (typically around 280 to 300 mm tall) with clearance. Bays 3 and 4 at 280 mm suit average-format hardbacks. The upper two bays at 217 mm clear height fit standard paperbacks (170 to 200 mm) comfortably.

Variation table: single vs double alcove

The most common question after working out a single unit is: how many sheets for a double alcove? Here is the count across the most common widths, all at 2200 mm tall with six shelves in 18 mm ply.

The key insight in the double-alcove row: building two bays as one unit with a shared centre upright saves one sheet compared to building them as two independent units. The centre upright is a single 2200 × 300 mm panel rather than two inner side panels.

A note on shelf sag

At 564 mm clear span, 18 mm ply shelves carrying books will not sag meaningfully. The practical threshold for 18 mm ply under a typical book load is around 700 to 800 mm before sag becomes noticeable. Up to 700 mm you can use 18 mm without concern. Above 900 mm, either use 25 mm ply or add a front lipping to increase the effective depth of the shelf edge.

UK sheet sizes and sourcing

The standard UK sheet is 2440 × 1220 mm (metric near-equivalent of 8 × 4 ft). All calculations above use this size. For US readers working in feet and inches, an 8 × 4 sheet is 2438 × 1219 mm: close enough that the cut list works without adjustment.

For a painted alcove unit, a hardwood-faced ply or MDF-faced ply from B&Q, Wickes or Travis Perkins gives a clean paintable surface. For a natural finish, birch ply is the standard choice: it has a light, consistent grain and takes oil or wax well. Both are stocked at the sizes used here.

If you want the merchant to do the first rips (cutting the sheets to 300 mm and 200 mm widths), call ahead and confirm they can cut to those tolerances. Most panel cutting services work to ±1 to 2 mm, which is fine for a painted built-in but worth verifying if you are expecting a tight fit.

Plan your own alcove cut list

Alcoves are rarely a standard size. The unit above is for a 600 mm opening; yours might be 550, 650 or 750 mm. The method is identical: measure the opening, decide your shelf depths and count, calculate the finished part sizes accounting for the 18 mm thickness, and nest onto sheets.

SawReady does the nesting and sheet count for you. Enter your parts, set the sheet size and your saw's kerf, and it returns the most efficient layout with a sheet count you can take to the yard. There will always be a free version if you want to try it before committing to the full tool.

Plan your bookcase cuts