Here is how you build a built-in wardrobe: measure the alcove or wall at several heights, use 18 mm board for the sides and shelves, build a carcass that you level up on adjustable blocks, and only then hang the doors. Allow one to two weekends of work. The real win is in the levelling, because no wall, floor or ceiling in an ordinary house is genuinely square, and that is exactly where most DIYers come unstuck.
In this article you will find out which board thickness goes where, how far a shelf can span before it sags, what sizes to work to for hanging rails and shoes, and how to fit a wardrobe under a sloping ceiling or into an out-of-square alcove. Plus an honest cost comparison: building it yourself versus having it made to measure versus an IKEA PAX.
Why a built-in wardrobe rather than an off-the-shelf one?
The big advantage of building it yourself: you use every centimetre. An off-the-shelf wardrobe comes in standard sizes, so you almost always end up with dead space between the wardrobe and the ceiling or the wall. Dust, not storage.
A built-in wardrobe runs cleanly from floor to ceiling and wall to wall. That gives you more storage on the same square metres, and it looks calmer because there are no gaps and no exposed edges.
The places where a built-in wardrobe really comes into its own:
- An alcove beside a chimney breast or between two walls. Often an awkward dead corner that you turn into proper storage.
- Under a sloping ceiling or against a knee wall. This is where an ordinary wardrobe wastes the most space. Made to measure, you fill the triangle right to the top.
- Under the stairs, where the height changes from shelf to shelf.
- A whole wall as a wardrobe run or a bookcase.
- In the hallway, a shallow unit for coats and shoes where no standard wardrobe will fit.
In short: the more out of square or the tighter the space, the more you gain from making it to measure.
Which material should you use for a built-in wardrobe?
You have roughly four options. Which one you pick depends on your finish (painted or not) and your budget.
| Material | What for | Watch out for |
|---|---|---|
| MDF (paint grade) | Sides, shelves, doors you are painting | Cut edges drink paint, prime them first. Swells and warps with damp |
| Plywood (birch/poplar) | Strong shelves, visible grain | Dearer, but strong and sags less |
| Melamine-faced board/chipboard | Ready-finished white, no painting | Finish the cut edge with iron-on edging |
| Solid timber | Country look, heavy loads | Moves with humidity, dearer and heavier |
For most built-in wardrobes you intend to paint, MDF is the obvious choice: smooth, affordable and easy to work. If you would rather not do any painting, a white melamine-faced board gets you finished faster, but then you do have to edge every visible cut with iron-on tape.
Watch one thing with MDF: it is sensitive to moisture and it can sag under its own weight. In a damp room or against a cold external wall, that is a risk. Prime every face, including the back and the cut edges.
Board thicknesses: what goes where?
This is where the strength is decided. Rules of thumb worth sticking to:
- Sides and shelves: 18 mm. The standard for cabinet work. Strong enough and not needlessly heavy.
- Back panel: 3 to 6 mm hardboard or thin MDF if the wardrobe sits against a wall and the back is only there to keep dust out. If the back has to carry any load or stand free, go up to 12 to 18 mm.
- Doors: 18 mm. Anything thinner will warp, certainly on larger doors.
How far can a shelf span?
The biggest beginner’s mistake: shelves that are too long with no support. A shelf loaded with books or stacks of clothes will sag in the middle. With MDF that is especially annoying, because MDF does not spring back the way plywood or solid timber does. Once it has sagged, it stays sagged.
Rule of thumb for 18 mm MDF or chipboard:
- Up to roughly 60 to 75 cm wide: 18 mm is fine for normal loads (clothes, light items).
- For heavier loads or spans over 80 cm: go to 22 to 25 mm, or add a mid support, or glue a batten (say 18 x 40 mm solid) under the back edge across the full width. That batten does most of the work against deflection.
- Bookshelves (genuinely heavy): keep to about 60 cm max at 18 mm, or make them thicker.
A bit of workshop wisdom: the problem often is not the weight at all, but that a stack just does not fit between two shelves and pushes the shelf up. An extra support or an adjustable shelf solves that.
How do you level a built-in wardrobe on a wonky wall?
This is the heart of good fitted work. Never assume your space is square. Walls bow in or out, floors fall away, ceilings undulate. So always measure at several points:
- Measure the width at the bottom, halfway up and at the top. Differences of 1 to 2 cm are perfectly normal.
- Measure the height on the left, in the middle and on the right.
- Check with a spirit level or a laser whether the floor and walls are actually straight.
Always take the smallest measurement as your working size, so the wardrobe is certain to fit. You fill the slack that is left over neatly afterwards with a scribe strip or a bead of sealant.
Levelling goes like this: stand the base frame or the bottom panel on levelling blocks or adjustable feet and wind them until everything sits dead level. Only once the base is level will the rest stand true. Carry on building on a sloping floor without levelling and the whole wardrobe leans, and the doors will not close.
Fix the wardrobe to the wall with cabinet hanging brackets or a screw and plug through the back rail, so it cannot tip forwards. On a tall wardrobe that is not a luxury, it is safety.
Mark your vertical and horizontal lines with a long straightedge and a spirit level or laser, not by eye.
Building a wardrobe under a sloping ceiling
Under a sloping ceiling or against a knee wall, one golden rule applies: your roof is not exactly the same anywhere. So do not try to copy the exact roof angle, work to a fixed, safe angle instead.
- Cut the sloping top at 45° if you can. That is an angle you can repeat everywhere and that closes up neatly, even where the roof is not quite true.
- Mark the sloping line by measuring the actual heights at several points and transferring them to your board. Cut the angle with a circular saw on a guide rail.
- A knee wall (the low straight bit of wall under the slope) is usually 100 to 150 cm high. Up to that height you build an ordinary square unit, and the sloping section sits above it.
- Back panels and doors that run into the slope get cut at the same angle.
That way you are not fighting a roof that varies by a centimetre, and your wardrobe still sits tight.
Joints and doors: how do you fix it all together?
The construction
- Screws plus wood glue is the most common and strongest basis for the carcass. Pilot drill and countersink so the MDF does not split.
- Dowels or biscuits/Dominos give an invisible, clean joint with no screw heads on show. Neater, but you need a biscuit jointer for it.
- Work from the bottom up and from the back forwards, otherwise you box yourself in and cannot reach.
Making the shelves adjustable
Drill a row of holes in the sides and sit your shelves on shelf supports. For adjustability, use the 32 mm system: a row of holes (usually 5 mm) at 32 mm centres. That is the industry standard, so fittings and supports from anywhere will fit. A drilling jig with that spacing makes the job quick and straight.
Doors and hinges
- Hinged doors give you a full view of everything when they are open. Sliding doors save space in the room, handy in a narrow hallway or bedroom. Handleless with push-to-open gives the cleanest, most modern look.
- Hinged doors go on concealed cup hinges. You drill the hole with a 35 mm Forstner bit.
- Drilling depth: 10.5 to 13 mm, depending on the hinge. Always check the packaging, because this varies from brand to brand.
- Keep the cups about 10 cm in from the top and bottom edge of the door. The distance from the cup to the side edge is set on the jig (often a few millimetres). A jig stops the holes going in crooked.
- Cup hinges adjust in three directions. On an out-of-square built-in wardrobe that is worth its weight in gold, because you can dial out the small differences.
The right sizes: laying out your built-in wardrobe
Made to measure only counts as made to measure if the inside works too. Ergonomic sizes worth working to:
| Element | Size | Notes |
|---|---|---|
| Depth for hanging | 55 to 60 cm | Any less and your coats bulge against the door |
| Rail for long garments (coats, dresses) | 180 to 200 cm high | Room underneath for the length |
| Rail for short garments (shirts, trousers) | 105 to 150 cm high | Two rails above each other saves space |
| Shelves (folded clothes) | min. 45 cm deep | About 30 to 35 cm of height between them |
| Shoe shelf | about 35 cm deep, about 25 cm per pair | Adjustable for tall boots |
| Rail to the shelf above | about 5 to 6 cm of clearance | Otherwise you cannot lift the hangers off |
Allow roughly 1.5 metres of rail per person for hanging clothes. Combine rails, shelves and drawers to suit what you actually store, because that is the whole point of designing it yourself.
Do not forget the plinth: leave room at the bottom for a plinth or a set-back foot, so you can stand with your toes against the wardrobe and the plinth closes neatly onto your floor.
Finishing: from sanding to topcoat
MDF only looks good once you finish it properly.
- Sand with 180 to 240 grit, the cut edges especially.
- Prime with an MDF primer or undercoat. Cut edges soak it up enormously, so give those a separate coat first (twice if needed). This prevents warping and a rough edge.
- Lightly denib after priming.
- Topcoat with two thin coats. Spraying gives the smoothest finish, but rolling with a foam roller can come out very well too.
With melamine-faced board you do not need to paint at all, you iron edging tape onto the visible cut edges with an ordinary household iron. Trim the excess with an edge trimmer or a sharp knife.
What tools do you need?
- Circular saw with a guide rail, or a plunge saw. For straight, clean cuts. No guide rail? Have the boards cut to size at the merchant, it saves a lot of faffing.
- Drill/driver with a countersink bit.
- 35 mm Forstner bit plus a jig for the cup hinges.
- Biscuit jointer if you are working with biscuits or dowels.
- Spirit level and/or cross-line laser and a long straightedge.
- Edging iron (or just a household iron) for melamine board.
- Tape measure, pencil, clamps, sander.
Step by step: from measuring up to fitting out
- Measure the space at several heights and widths. Write down the smallest figure.
- Draw your design to scale: the front elevation and the internal layout with rails, shelves and drawers.
- Work out the cutting list board by board, allowing for board thickness in your sizes (a bottom panel between two sides is shorter than the outside dimension).
- Choose and order your material. Have it cut to size if that suits you.
- Prime the MDF before assembly, that works far easier than getting into the corners afterwards.
- Build the carcass: sides, bottom, top and back. Glue and screw.
- Stand the wardrobe on levelling blocks and level it up. Fix it to the wall.
- Drill the shelf holes (32 mm system) and fit the supports.
- Hang the doors on their cup hinges and adjust them until the gaps are even.
- Finish off: scribe strips along the wall and ceiling, plinth at the bottom, final topcoat.
What does building a built-in wardrobe cost?
An honest comparison, because this is often what decides it. These are ranges, not exact prices, because a lot depends on size, material and fittings.
| Option | Ballpark price | What you get |
|---|---|---|
| Building it yourself from MDF | Material from a few hundred euros | Fully to measure, you supply the hours. Fittings and paint on top |
| IKEA PAX (fitted in/hacked yourself) | Around €500 for a wall-length run | Ready-made carcasses that you fit in neatly yourself with doors and filler strips |
| Having it made to measure | Roughly €1,000 to €3,000, or around €250 per linear metre | Proper craftsmanship, a perfect fit, nothing for you to do |
The PAX hack is a popular middle way: you buy affordable carcasses and make them look built in with doors up to the ceiling and filler strips. Cheaper than a joiner, but less freedom than cutting everything yourself.
Doing it entirely yourself in MDF is the cheapest on material, but allow one to two weekends of work plus the painting. Can you cut cleanly and do you have the patience for the levelling? Then this gets you the most fitted joinery for the least money.
Common mistakes
- Not levelling. The wardrobe leans and the doors will not close. Always level it up on blocks.
- Measuring at one point only. The space is not square, and your wardrobe just does not fit.
- Forgetting board thickness in your sizes. Your bottom panel is 36 mm too long if you do not subtract two lots of 18 mm.
- Shelves too long with no support. They sag, MDF especially.
- No allowance for the plinth and the floor. The wardrobe does not meet the skirting, or it fouls a floor that falls away.
- Cut edges left unprimed. The edge stays rough and the paint goes flat and dead.
Frequently asked questions
What board thickness for a built-in wardrobe?
18 mm for sides, shelves and doors. For shelves wider than 80 cm go to 22 to 25 mm or add a support. A thin back panel can be 3 to 6 mm if it is only there to keep dust out.
Which material is best for a built-in wardrobe?
If you want to paint it, MDF is the obvious choice: smooth and affordable. If you would rather skip the painting, go for a white melamine-faced board and finish the edges with iron-on tape. Plywood is stronger and sags less, but it costs more.
How do I get my built-in wardrobe true on a wonky wall?
Measure at several points and take the smallest figure. Stand the wardrobe on levelling blocks or adjustable feet and level it up before you build any further. Finish the joint against the wall with a scribe strip.
How do I build a wardrobe under a sloping ceiling?
Build a square unit up to the knee wall (100 to 150 cm) and cut the sloping section above it at 45° if you can. Measure the roof height at several points, because a roof is not exactly the same anywhere.
How do I drill a hole for a cup hinge?
With a 35 mm Forstner bit, drilling depth 10.5 to 13 mm (check the packaging). Keep the hinges about 10 cm in from the top and bottom edges, and use a jig to keep the holes straight.
Is building a built-in wardrobe yourself cheaper than having one made?
Yes, on material you are often looking at a few hundred euros against €1,000 to €3,000 for made-to-measure. You pay with your own time: allow one to two weekends plus the painting.
Get started with a good drawing
A built-in wardrobe stands or falls on the preparation. Measure up properly first, draw it to scale and work out the cutting list, and you cut once and build without surprises. Improvise, and it costs you twice the timber and twice the good mood.
Would you rather not puzzle over sizes and cutting lists yourself? At Fred’s DIY Plans you will find clear furniture and cabinet plans that tell you exactly what to cut, how to level it and how to join it all together. That way you start with a plan instead of a guess, and your wardrobe ends up dead straight in the alcove. Good luck with the build.