Built-In Wardrobes & Storage: Frame Construction, Sliding Doors & Maximising Space

Quick Answer: Built-in wardrobes are typically framed from 18mm MDF or 18mm plywood, with shelf loads requiring a maximum span of 900mm unsupported for standard 18mm MDF shelving. Sliding doors require a level, plumb, and square opening — tolerance of ±2mm over the door height is the practical maximum. Building Regulations do not generally apply to freestanding or built-in furniture, but any structural alterations to walls to create alcove space may require Building Control notification.

Summary

Built-in storage is one of the highest-value carpentry jobs in terms of customer satisfaction. Done well, it transforms a bedroom or hallway, makes a property feel custom and premium, and maximises otherwise dead space in alcoves, under stairs, and sloping ceilings. Done badly — with frames that rack, shelves that sag, or sliding doors that bind and jump their tracks — it generates disproportionate callbacks and unhappy customers.

The core skill is joinery sequencing: measuring precisely, scribing to irregular walls, building the carcass square independent of the walls, and then fitting panels to the reveals. Many tradespeople make the mistake of trying to make the carcass fit the wall rather than building the carcass square and scribing panels to the wall. The latter produces better results because walls are rarely plumb, level, or flat.

Sliding door systems have become the dominant choice in UK bedrooms over the past decade. The principal trade names — Hettich, Hafele, Spacepro, Wardrobes Direct — all use broadly similar track systems but with specific installation tolerances. The floor-to-ceiling sliding door look that customers show in Pinterest inspiration images requires very precise plumb installation, ceiling-height clearance (or dropped soffit), and a track system rated for the door weight.

Key Facts

Quick Reference Table

Spending too long on quotes? squote turns a 2-minute voice recording into a professional quote.

Try squote free →
Component Standard Dimension Material Notes
Side panels 18mm × 600mm depth MDF or plywood Scribe to wall if in alcove
Top panel 18mm × same depth MDF or plywood Check for ceiling flatness
Bottom panel/plinth 18–25mm MDF or timber Load-bearing — plywood preferred
Shelves (light duty) 18mm × 500–600mm span MDF Edge-band front edge
Shelves (heavy duty) 18mm ply or add support Plywood Span max 900mm
Back panel 6mm MDF or hardboard Keeps carcass square
Hanging rail 25mm diameter tube Chrome steel Span max 900mm; use centre support over 900mm
Sliding door track To manufacturer spec Aluminium Dead level; wall plugged at 200mm centres
Soft-close buffer To manufacturer spec Nylon/steel Fit to door panel edge

Detailed Guidance

Planning and Measuring

The most important phase of any built-in project is the initial survey. Measure the width, height, and depth of the opening at multiple points — top, middle, and bottom for width; left, right, and centre for height. Record the worst-case dimension for each. Walls in UK houses are rarely perfectly parallel or plumb; alcoves from Victorian chimney breast removal often have a plaster reveal that is 10–15mm out of square.

Check the floor for level using a spirit level and identify the high point. If the floor drops more than 5mm, you may need to use a trim strip or packer at the low side to keep the base panel level. Check the ceiling for level in the same way.

Photograph the space with measurements clearly visible, or use a sketch with dimensions. This forms your record of site conditions and protects you if the customer queries the final dimensions during snagging.

Carcass Construction

Build the carcass flat on the floor before standing it up. This is far easier than trying to fix pieces in position in sequence. Use a pocket hole jig (Kreg or similar) for strong, hidden fixings, or confirm-and-cam (euro screws) for a factory furniture appearance.

Sequence: fix bottom panel to side panels first, then top panel. Fit the back panel last — use the back panel to square the carcass by measuring diagonal dimensions and adjusting until equal before pinning the back.

For tall wardrobes (full ceiling height), the carcass is typically made slightly shorter than the floor-to-ceiling height to allow it to be tilted upright. A scribing moulding or cornice at the top covers the gap between the top of the carcass and the ceiling.

Internal dividers (for separate hanging/shelving bays) are typically dadoed or housed into the top and bottom panels using a 18mm-wide housing joint (router or table saw). This prevents the dividers from racking under load.

Scribing to Irregular Walls

If the wardrobe is in an alcove with masonry walls, the side panels will need to be scribed to the wall profile. Set the panel in position with a 10–15mm gap to the wall. Set a compass to the maximum gap dimension and draw a pencil line along the panel face, tracking the wall profile. Cut along this line with a jigsaw (gentle curve) and the panel will fit snugly against the wall.

For straight walls that are simply out of plumb, a scribing strip of solid wood (25mm wide) is glued to the back edge of the panel and planed to the wall angle. This avoids cutting the main panel and is quicker.

Caulking and silicone: always finish the scribed joint with decorator's caulk (paintable) before painting. A scribed joint that is not caulked will develop a visible gap as the house moves through seasons.

Sliding Door Installation

Top-hung sliding systems (most common in domestic applications) use a top track fixed to the ceiling or to a head rail. The doors hang from roller carriages that run inside the track. The floor guide is a simple channel or pin that keeps the bottom of the door from swinging.

Step 1: Fix the top track dead level. Use a long level or laser level — even 1–2mm over 3m will cause noticeable drift. Fix through the track at maximum 200mm centres using plugs and screws into solid material (ceiling joist, timber head, or masonry soffit).

Step 2: Hang the doors and adjust the roller height to ensure the door is perfectly vertical. Virtually all systems have screw-adjusted rollers — turn to raise or lower each corner of the door independently. Check with a level or plumb bob.

Step 3: Fit the floor guide. This is usually adjustable in the panel thickness direction only. Set so it guides the door without binding.

Step 4: Adjust the soft-close mechanism (if fitted). Typically a nylon buffer at each end of the track that engages the roller carriage for the last 30–50mm of travel.

Maximising Space — Design Tips

Under-stairs storage: the most underused space in UK homes. Measure the headroom at each point along the stair string. Design pull-out drawers for low areas (under 600mm), fixed shelves for mid-height areas, and a tall door unit for the highest area. Bespoke carpentry is required for stepped profiles but the result is transformative.

Sloping ceilings: use low-level drawers and shoe rails at the shallow end, full-height hanging at the tall end. A horizontal beam spanning the space at hanging height creates the hanging rail without needing it to go all the way to the ceiling at the sloped section.

Bedroom alcoves: fit full-height MDF panels to close off alcoves flush with the chimney breast face, creating a unified wardrobe run. Internal shelf and drawer fitments can be standard flat-pack components dressed with the external MDF frame.

Corner wardrobes: carousels or lazy susans for true corner access, or accept a dead zone in the extreme corner behind full-height doors. Walk-in L-shaped configurations require a minimum room depth of 900mm per arm plus the door swing width.

Painting and Finishing

Spray painting MDF wardrobes gives the flattest, most professional finish but requires a spray booth or well-sealed workspace. Water-based satin or eggshell is most commonly specified.

For site painting: sand all faces to 120 grit, apply MDF sealer or watered-down eggshell as a primer coat, sand to 240 grit, then apply two topcoats. Internal faces are typically painted the same colour as the external finish or left white. Do not omit priming MDF edges — unprimed MDF edges absorb paint aggressively and remain rough.

Door faces: for large painted slab doors, use moisture-resistant MDF (green MR MDF) to minimise expansion. Moisture-resistant MDF is essential for any room with elevated humidity. Standard MDF doors in a bedroom are acceptable.

Frequently Asked Questions

Do I need Building Regulations approval for a built-in wardrobe?

In most cases, no. Fitted furniture in an existing room does not require Building Regulations approval. The exception is if you are making alterations to the structure — for example, removing a partition wall to create alcove space, or cutting through a structural wall. Any structural alteration requires Building Control notification.

How do I prevent shelves from sagging?

Use the correct span-to-thickness ratio. For 18mm MDF, maximum 900mm unsupported span for clothes and 600mm for books. For spans over 900mm, add a central support bracket or upright divider, or use 25mm MDF or 18mm plywood which is stiffer. Beware: even a correctly sized shelf will sag if overloaded — a shelf of folded clothes at 15kg can deflect 5mm over 900mm in MDF within a year.

How do I stop sliding doors from jumping the track?

Three common causes: (1) floor guide missing or too loose — the door is twisting and lifting the rollers; fit the floor guide and adjust. (2) Rollers are worn or dirty — clean and lubricate the track with a dry lubricant (silicone spray, not WD-40 which attracts dust). (3) Top track is not level — readjust with shims.

What is the minimum depth for a functional wardrobe?

600mm internal depth for full clothes hanging (400mm minimum hanger width plus clearance for door opening and air circulation). 500mm is marginal — hangers project slightly beyond the opening. 450mm is usable for folded items and shoes only. Always confirm the customer's intended use before fixing depth.

Regulations & Standards