Sash windows and bay windows are common in period London houses, and the space beneath them is often wasted. A window seat turns it into somewhere to sit and read, with storage underneath. It also gives the window a finished, built-in look.
A good window seat has to suit the window above it, the radiator that’s often below it and the wall it sits against. This guide explains what to think about before you commission one.
Bays, sashes and flat windows
Bay windows give the most room. A seat can run across the front of the bay and along the angled sides, or just across the middle. The angles in a bay are rarely identical, so each section is made to suit its own wall.
Sash windows in a flat wall suit a simpler seat set into the window reveal or built between two cupboards. The seat must let the sashes open and close easily, and leave room to reach the catches and any cords.
If you have working shutters, the seat needs to leave them room to fold back. We look at all of this at the design visit.
Working with the radiator
Radiators are often fitted under windows. A seat can be built over one, but the heat must still reach the room. That means a grille or an open front in the seat so warm air can rise and circulate, and space around the radiator so it isn’t boxed in tightly.
We build the seat and grille around the radiator. If you want the radiator moved, changed or taken out, that’s work for your plumber, and it’s best done before the seat is measured.
Storage under the seat
There are two main options:
- Lift-up lids. Simple and roomy, good for bulky things like blankets, toys or cushions. You do have to clear the seat to open them.
- Drawers. Easier to use day to day, and you can open them while someone is sitting there. They take up a little more of the space for their runners and boxes.
Some seats combine both, with drawers at the front and a lid behind. Where a radiator sits under part of the seat, that part is usually left open for heat and the storage goes elsewhere.
Thinking about fitted furniture? We design, make and fit it across London: we visit, measure and talk through the design, then send a written quote. Arrange a design visit.
Damp and cold under windows
The wall under a window is often an external wall, and external walls can be colder and damper than internal ones. Condensation from the glass can run down too. Leaving a small gap behind the storage, adding some ventilation and using moisture-resistant MDF all help. Any existing damp should be sorted before the seat is fitted. See external walls, damp and ventilation.
Comfort and finish
A seat should be a comfortable height to sit on and deep enough to sit back in, with a cushion on top. The cushion and any fabric are chosen by you. We can allow for the thickness of the cushion in the design so the finished seat height feels right.
The seat itself is made in our workshop from moisture-resistant MDF and birch plywood, then spray painted or hand painted in a colour agreed with you. Matching the paint to your window frames or skirting boards helps the seat look like part of the room.
Pairing a seat with other furniture
Window seats often sit between fitted bookcases or cupboards, which frame the window and add more storage. In a bay, low cupboards along the sides can do the same. See our window seats and built-in bookshelves pages for ideas.
Quick answers
Can you build a window seat over a radiator?
Yes, with a grille or open front so heat isn’t trapped. Moving or changing the radiator itself is for your plumber.
Will a window seat stop my sash windows opening?
It shouldn’t. The seat is designed to leave the sashes, catches and any shutters working.
Lid or drawers: which is better?
Lids give more open space for bulky things. Drawers are easier to use every day. Many people choose a mix.
Do you make the cushions?
No. You choose the cushion and fabric. We can allow for its thickness in the seat height.
Related services
More advice
- Storage Ideas for Victorian and Edwardian Terraces
- Fitted Furniture on External Walls: Damp and Ventilation
- Built-in Bookshelves: Depths, Spans and Sag
- Fitted Storage for Children’s Rooms
- All advice
This guide is general information about fitted furniture. It isn’t legal, planning or building advice; for those, speak to the council, your landlord or managing agent, or a suitably qualified professional.