How to Make a DIY Window Seat Cushion
Why add a window seat cushion?
A window seat is a pleasant addition to any room, a comfortable place to read, unwind or take in the view. To get the most comfort, the cushion matters: a well-made DIY window seat cushion offers the ideal balance of comfort and style, whether you're building a new seat or refreshing an old one. Choosing the right foam and having it cut to size precisely is key, and a soft cushion enhances the room's appearance too.
Types of window seat cushion
There are several styles to consider when choosing or making a window seat cushion: bench-style cushions are flat and cover the whole seat for steady support; tufted cushions add sewn buttons or patterns for a more ornamental look; boxed-edge cushions have a neat, fitted appearance with piping around the edges; pillow-top cushions are overstuffed for extra softness; and custom shapes can be cut to size for a precise fit, ideal for a bay window or unusually shaped seat.
What foam is best for a window seat?
The right foam is essential for comfort and longevity. High-density foam offers firm support and holds its shape, ideal for frequently used seats. Memory foam provides a luxurious, body-moulding feel. Reticulated foam is water-resistant and breathable, perfect for humid environments. Whichever you choose, our cut-to-size service ensures a precise fit and the right support.
How thick should the foam be?
Thickness depends on comfort and use: around 2 inches suits light, decorative seating; 3 to 4 inches balances support and comfort for frequent use; and 5 inches or more suits high-traffic areas. A 3 to 4 inch cushion is the most popular choice.
Materials and tools
To make your cushion you'll need window seat foam cut to size (your choice of thickness and type), durable easy-clean fabric, and polyfibre/Dacron batting for added softness. You'll also need a measuring tape, sharp scissors or an electric knife for the foam, fabric scissors, a sewing machine, a staple gun (if attaching fabric to a wooden base), pins, and chalk for marking.
Step-by-step
- Measure the window seat's length, width and depth to find the dimensions for your foam and fabric.
- Cut the foam to size accurately with an electric knife or sharp scissors.
- Wrap the foam in polyfibre or Dacron batting for a smoother, softer finish, trimming any excess.
- Cut your fabric with a 2-inch margin on all sides for seam allowance and wrapping.
- Sew the fabric together, leaving a Velcro or zip opening to insert the foam.
- Insert the foam so it fits snugly inside the cover.
- Sew or seal the cover closed, then place the cushion onto your window seat.
With the right supplies, a bespoke window seat cushion is a satisfying, economical project that adds comfort and style. For related ideas, see our guides to foam floor cushions and beach hut interior foam.
Frequently asked questions
What type of foam is best for a window seat cushion?
High-density foam gives firm support and holds its shape for frequently used seats; memory foam offers a luxurious, body-moulding feel; and reticulated foam is water-resistant and breathable, ideal for humid environments. Cut to size, it fits your seat precisely.
How thick should a window seat foam cushion be?
Around 2 inches suits light, decorative seating; 3 to 4 inches gives a good balance of support and comfort for frequent use; and 5 inches or more suits high-traffic areas. Three to four inches is the most popular choice.
What do I need to make a DIY window seat cushion?
Window seat foam cut to size, durable easy-clean fabric, and polyfibre/Dacron batting. Tools include a measuring tape, an electric knife or sharp scissors for the foam, fabric scissors, a sewing machine, a staple gun, pins and chalk.
