Maximising Space Under a Bay Window

A bay window is one of the loveliest features in a British home and one of the most poorly used. All too often the space in front of it holds a pot plant, a drying rack, or nothing at all, while the rest of the room is cramped for seating. Yet the geometry of a bay is almost purpose-built for a reading corner: it is bright, it is usually a little apart from the main traffic of the room, and the recess beneath the sill is often dead space. With a fitted window seat, some concealed storage and a pair of slim shelves, you can turn an awkward alcove into the best seat in the house.

Start with the Measurements That Matter

Before you buy anything, spend twenty minutes with a tape measure and a notebook. You need four figures: the width of the bay at the back wall, the width at the window line, the depth from the main wall to the window reveal, and the height from floor to the underside of the sill. In most Victorian and Edwardian terraces the bay projects between 400mm and 600mm, which is tight but workable. If your sill sits at around 750mm from the floor, you have room for a seat with storage below. If it is lower, think about a low platform with drawers rather than a lift-up lid.

Also note the position of radiators, sockets, trickle vents and curtain tracks. Measure the return walls on either side of the bay — those narrow strips are where slim shelving earns its place. A quick sketch, even on the back of an envelope, will save you a great deal of frustration later.

Building a Seat That's Actually Comfortable

The single most common mistake is making a window seat too tall and too shallow. Sit on a dining chair and measure from the floor to the top of the seat pad: that is your target, usually 450–480mm. Once the cushion is in place, the seat should land at roughly that height, so build the base slightly lower. For depth, 500–550mm is comfortable for sitting upright with a book; 600mm lets you tuck your legs up sideways, which is what most people actually do.

• Seat height: 450–480mm from floor to the top of the cushion.
• Seat depth: 500–600mm, depending on how you like to sit.
• Base: a simple MDF or plywood box, braced to the wall, with a solid top.
• Cushion: 75–100mm of firm foam, wrapped in a thin layer of wadding, with a removable, washable cover.

If the bay is very wide, break the base into two or three sections so the lid and the cushion are manageable. A single 2.5-metre cushion looks handsome but is a nuisance to lift and clean.

Storage That Earns Its Keep

Under-seat storage works best when it suits what you are storing. Books, blankets and board games are heavy, so keep them low and spread the weight. A lift-up lid on gas struts gives you the full depth of the void and is ideal for bulky items. Drawers, by contrast, are easier to reach but need a clear pull-out zone — usually about 400mm of floor space in front, which a narrow bay cannot always spare.

A practical compromise is a hinged lid over the deeper central section and shallow drawers at each end. Divide the interior with vertical panels so everything does not slide into one heap. Leave a 100–150mm gap above any radiator and keep the front of the boxing open or slatted so warm air can rise; trapping a radiator behind solid timber will make the room feel colder, not warmer. If the void under the seat is cold and damp, line it with a breathable membrane rather than sealing it completely.

Slim Shelves and the Reading Corner

The return walls either side of a bay are perfect for shelves, and they need not be deep. A shelf 150–200mm deep holds paperbacks comfortably; 250mm takes most hardbacks and a small lamp. Fix battens into the masonry with suitable plugs rather than relying on plasterboard fixings, and space the shelves 250–300mm apart, or a little more if you have oversized art books.

Run the shelves from just above the seat to as high as you can comfortably reach — around 1,800mm is a sensible ceiling. Two or three shelves on each side, painted the same colour as the walls, will frame the window without crowding it. Add a small corner shelf at seat level for a mug and a pair of glasses, and you have a reading spot that feels deliberate rather than improvised.

Light and Warmth

Bay windows are bright in the morning and often chilly after dark, so plan for both. Install a socket or a spur inside the seat void before you close it up; a small lamp tucked in the corner transforms the space at night. A warm-white LED strip beneath the lowest shelf gives a soft wash of light for evening reading without glare.

For warmth, choose Roman blinds or curtains that finish at the seat rather than pooling behind it, and consider thermal lining if the bay faces north or the glazing is single. Keep the palette simple — soft off-whites, warm greys, a deep green or navy on the seat — so the window itself remains the focal point.

Keeping It Practical Year-Round

Bays attract condensation, so avoid boxing in the window reveal so tightly that air cannot circulate. Open the lid of the seat occasionally, dust the shelves, and vacuum the cushion seams where crumbs collect. Choose moisture-resistant MDF for the base and finish it with eggshell or a hard-wearing chalk paint sealed with wax.

Finally, remember that a window seat is furniture, not a permanent fixture. Build it so it can be lifted out if you ever replace the windows or redecorate, and you will have a piece that serves the room for years. Done well, this overlooked corner becomes the calmest, brightest place in the house — and the one everyone quietly competes for.