Start With the Awkward Geometry

Under-stair space is always bigger in the imagination than it is in reality. Before you order a single runner or sheet of plywood, spend an hour measuring properly. The shape is a wedge, and the usable depth changes with every step you go back.

Work along the run in 200mm intervals. At each point, record the height from the floor to the underside of the stairs, and the depth from the front face to the back wall. You will usually find somewhere between 300mm and 400mm of depth at the shallow end, deepening to 900mm or more at the tall end. A standard stair rises around 180–220mm per step, and that diagonal line is what dictates everything.

• Find the stringer. The diagonal timber that carries the treads is your best fixing point. Mark its line on the wall with masking tape so it stays visible while you work.
• Look for services. Stopcocks, meter boxes, consumer units, radiator pipes and boxing all hide under stairs. Anything that needs access must stay accessible, so plan a hinged panel rather than sealing it behind a drawer.
• Check the floor and walls. Victorian floors slope, skirtings vary in thickness, and the back wall is often the coldest in the house. Measure at floor level as well as at working height.

A quick trick: cut a cardboard template of the wedge in two or three places and offer it up. It is far cheaper to discover a bulge in the plaster now than after you have cut your drawer boxes.

Pull-Out Drawers: The Best Use of Deep, Low Space

Drawers beat cupboards in almost every under-stair situation, because you can reach the whole depth without kneeling on the hallway floor. They also suit the low end of the slope, where a hinged door would be unusable.

Build a simple timber carcass from 18mm plywood and fix it to battens screwed into the stair timbers — never rely on plasterboard alone to carry a loaded drawer. Then choose runners carefully. For anything holding shoes, tools or tins, use full-extension ball-bearing runners rated to at least 45kg. Cheaper half-extension runners waste the back third of the drawer, which is exactly the space you are trying to reclaim.

• Keep shallow drawers (150mm deep) at the low end for shoes, hats, gloves and charging cables.
• Reserve the tall end for 250–300mm drawers holding boots, board games or recycling.
• Allow 50mm of clearance behind the drawer front so it opens without catching the slope.

If the space is very deep, consider a pull-out truck on braked castors instead of runners. A single 600mm-wide truck on 50mm castors can carry 60kg and slides out as one unit, which is ideal for awkward cleaning equipment.

Coat and Boot Storage That Actually Works

The tall end of the staircase is prime hallway real estate, and coats are usually what people want there. Just be honest about the depth. An adult coat needs roughly 600mm front-to-back to hang properly on a rail. If you only have 400mm, hang garments sideways on a pull-out rail or use a run of sturdy hooks at two heights.

A bench section transforms the space. Set the seat at 450mm high with a minimum depth of 400mm, and put a drawer beneath it for leads, bags and umbrellas. Above, add a shelf with a lip to stop hats sliding off, and a shallow tray for keys and post. A wipeable painted finish on the bench takes knocks and muddy paws far better than veneer.

If the space is open to the hall, keep the front profile neat. Aligning the door or drawer fronts with the stair nosing makes the whole staircase look intentional rather than boxed in.

A Compact Pantry for the Tall End

Where the underside clears 1.6m or so, a pantry is a genuinely useful option — particularly in flats where the kitchen has run out of cupboard space. Pull-out baskets on runners let you see everything at a glance, and they are far easier to keep tidy than a deep fixed shelf.

Keep dry goods in sealed glass or plastic containers; under-stair areas are often cooler and slightly damper than a kitchen wall cupboard, so flour and cereals need protection. Avoid storing anything sensitive to heat near a boiler or radiator pipe, and never block the ventilation gaps around a meter.

• Fit a vent grille in the door or leave a 25mm gap at the top and bottom to keep air moving.
• Use moisture-resistant MDF or plywood, sealed on all faces, if the back wall is external.
• Line shelves with a washable mat so spills lift straight out.

Fittings, Fixings and Finishing Touches

Soft-close hinges and runners cost a little more and are worth every penny in a hallway, where doors get shut with a hip while your hands are full. For doors, bifold or sliding options work best where the hall is narrow — a standard hinged door swinging into a 900mm corridor is a daily annoyance.

Lighting is the finishing touch that makes the space usable. A warm-white LED strip (2700–3000K) fixed under the stair stringer, on a motion sensor, means you can find a coat without switching on the hall light at 6am. Add a small magnetic catch or push-to-open latch where handles would catch on passing shoulders.

Mistakes That Trip Up Under-Stair Projects

• Fixing to plasterboard. Always find timber behind it, or fit a batten spanning at least two studs.
• Forgetting the door swing. Measure the arc before you commit to a hinge side.
• Ignoring access. Meters, stopcocks and junction boxes need a removable panel, not a sealed carcass.
• Overloading the top drawer. Keep heavy items low, where the runners and floor share the load.
• Skipping the paint. Seal every cut edge of MDF, or it will swell the first time a wet umbrella rests against it.

Get the measurements right, choose the fitting to suit the depth, and that awkward wedge beneath the stairs becomes the hardest-working storage in the house.