How to Build a Window Seat with a Cushion & 2 Incredible Built in Bookcases

Sharing all the tips & tricks for how to build a window seat with a cushion & 2 built in bookcases for a large picture window with an attic sloped ceiling in our son’s bedroom.

His new seat & matching bookshelves add a ton of character, save space in his narrow room & look fabulous!

Our window seat & built in bookshelves have definitely become our kid’s favorite spots to cozy up & read.

How to Build a Window Seat with a Cushion & 2 Incredible Built in Bookcases

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We have been turning our former master bedroom closet into a bedroom for our youngest son Tucker.

You have to get creative when you have 4 kids & not enough bedrooms. 🙂

If you are wondering if we still have a closet… yes we build one HERE.

Instructions for How to Build a Window Seat

Here is our wall soon after we added a window to it. Our former closet had no windows & was very dark!

Measure your Window

The first thing you need to do is measure your window & decide how big you want your window seat.

We went with a 5 foot seat which allowed for 18 inch bookshelves on either side.

Making a Frame for the Window Seat

After determining the size you want your window seat, make the frame for your built in window seat bench.  

Securing your Window Seat Frame to the Wall

Find the studs in the wall & screw the back frame to the wall studs as well as the floor. This will ensure that your window seat bench is secure.

Next, Install the seat sides by screwing them to the back frame & floor.  

Last, install the front frame by screwing it to the side frames and floor.

Framing out the 2 Bookcases on either side of your Window Seat Frame

Begin framing out the bookshelves.  We chose to build the shelves a little off the floor to allow for baseboard to wrap around both.

Facing the Bookcase & Bookshelves for a Beefier Look

Anytime you are building built in bookshelves it is a good idea to face the bookshelf frame and shelves with 1 by 2’s.  

It gives the bookshelf a beefier & solid look. It also helps the bookcase or bookshelves more finished.

Face the top of the built in seat & sides with plywood.

Jason ripped down some 1 by 2’s and added some vertical molding to the front of the window seat to give it interest.  

Priming & Painting your Window Seat & 2 Built in Bookcases

Once you have it all framed prime the raw wood & give the whole thing a couple coats of paint.

How to Build a Window Seat Cushion with Upholstery Foam

I made the window seat cushion with some upholstery foam, wood, a staple gun & canvas from Fabric.com. 

First, I traced the MDF board to match the size of the window seat. Next, I cut out the upholstery foam with a knife slightly larger than the MDF board. I cut & stapled the dark blue denim fabric around the MDF board to finish it off.

Decorating & Adding Pillows for the Window Seat

It was time to retire Tucker’s old pillows from his nursery & make him some new pillows to add to his new spot by the window. 

I hand embroidered one of Tucker’s new pillows with his name to make it more personal & added a few navy blue & plaid pillows to match.

Tucker loves to sit here and play transformers, look at books and wait and watch for his big brothers and sister to get off of the bus. 

Can’t you just imagine a new puppy sitting at this window? 🙂

Adding a Window Shade above the Window Seat

For the window… I found Tucker’s shade at the Restoration Hardware outlet for $18!  It had a $189 price tag on it.  Awesome!

Jason made extra window molding to trick the eye to think the window was taller than it was because we didn’t want the shade to cover any of the natural light coming in the window since it is the only window in the room.

Next up for Tucker’s room is adding hardwood floors. You can see how we added wide pine floors HERE.

We picked out the wide plank pine flooring from lumber liquidators like the ones we put in the laundry room. 

As you can see from this picture, we wasted no time taking advantage of our new window seat!

Here is our little man “reading” one of his many truck books 🙂

Our Boys Built in Bedroom is Done, See the whole DIY here.

I hope this post inspires you & answers all your questions about how to build a window seat with a cushion & 2 built in bookcases!

by Tara Lehman

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