Making a bay window seat requires some planning. First, determine if there is enough space to accommodate a seat below the bay window. It is recommended that the windows be at least 18” above the floor. The bay window seats should include end tables that are taller than the seat on both sides and storage underneath the seat itself accessible by designing the actual seat with a lid made of plywood.
To build a bay window seat that is 8' or less in length, you will need 1 piece of 3/4 ac grade plywood (paintable/stainable), 1 pound of 8d finish nails, 5 pound 16d framing nails and 8 2x4s 8' in length, along with 1 piece of paper 2' wide and 10' long builders felt.
Use a pattern to ensure accuracy using the paper and the felt, measure 3 times before cutting any wood and always wear safety glasses.
Measure and cut all of the pieces of wood first, including the seat, which should be made out of plywood. Clamps, glue and nails will be used to hold the parts together during assembly.
Step #1: Attach the ends to the base of the seat with clamps and glue and nail them together.
Step #2: Attach the sides in the same manner. This will result in a base box for the seat assembled with 1x4s. It should resemble a planter box.
Step #3: Build a recessed wall across the front of the bay window 1-1/2 inches from the wall. Secure the 2x4 studs with 2 nails each at the top and the bottom at the center of the seat. Make sure the wall is ¾” less than the desired height taking into consideration the height of the cushions.
The next step is to conceal the rough edges of plywood.
Step #1: Using a biscuit joiner cut a crescent-shape into the two pieces of wood you wish to join, i.e. the plywood and the more finished wood, so that the slots match.
Step #2: Glue an oval-shaped biscuit with one end into each of the matching slots to join the pieces of wood together. Since the biscuit will swell with the glue, the joint will become strong. Clamp everything together to allow the glue to take hold.
Step #3: Glue strips of wood to the top edges of the base, lid and wall and then nail them down. This will conceal the top edges of the plywood. Secure the hinges and then test the lid to make sure it fits.
Step #1: The end tables are made as triangular boxes with a triangular base and three sides using glue and nails in the same fashion as the seat was made.
Step #2: One end table will have a lid designed in the same way as the seat lid.
Step #3: The other will be solid at the top but with shelves.
Paint or Stain
Step #1: Use a primer containing a stain blocker. This will prevent any bleeding.
Step #2: Apply one coat of paint after the primer has dried.
Step #3: Sit down and enjoy your bay window seats.
Plants can be hung from the ceiling to add some additional color to the bay window seating.