Built in Bookshelves with Window-seat for under $350

window seat with bookshelves title

When we finished our basement a couple of years ago, we made one room an office and lined the walls with IKEA Billy bookshelves. This summer, when we decided we never really used the office and the space would be better as an art studio, we needed to do something with the books and some of the bookshelves to make room for the large craft tables we now wanted for the space.

A friend mentioned an IKEA Hack. I looked it up on-line and became inspired. Not only would we be able to use the bookshelves we already owned, but we could add some character to our living room.


Our wall was 158″ with a window slightly off-center, so a row of bookshelves would not work. I have always loved and wanted a windowseat, we looked around and decided the Benno TV Bench was a good height for that, the pull-out drawers would be great for blankets or games and we could get nice baskets for the shelves. The Benno shelf was 47′ 1/4″ wide, so that left 110 3/4″. The next challenge was that the regular shelves were 31″ wide and the narrow shelves are 15″ wide, we didn’t have enough room for two regular size shelves on each side and a regular size shelf and a narrow shelf on each side was not wide enough. We ended up deciding to use the two regular size BILLY bookcases we had and buy two more regular size BILLY bookcases and cut the top, bottom and all the shelves to the size we needed.


Once the planning was done, the girls and I went to work on pulling off the old trim so the shelves would sit flush against the wall.
piper removing trim
Piper pulling the old molding off the wall

I taught the girls how to pull off the trim.

piper removing trim 2
piper removing trim 3

Jason helped us cut the molding on the sidewalls so the bookshelves could fit flush against the walls on the side.

removed trim
We cut the trim on the side walls so the shelves would sit flush against the wall.


loose bookcases
My living room stayed like this for quite a while.
There was a lot going on this summer.

When we put the bookshelves together, we decided that we would rather have the wall exposed in the back than put the {cheap} cardboard Ikea gives you on the back. But then we were left with an unsightly track for the cardboard. I tried caulk, but it didn’t work right and neither did wood filler. Joint compound (spackle) seemed to work best.

painting bookcases
We realized that many built-in wall shelf units use the actual wall as the backboard.
We liked the idea of the wall color showing through and we worried that something would happen to the {cheap} IKEA cardboard–slipping, bowing–and if it was built-in it would be hard to get to to fix, so we left the backing board off.
joint compound
Joint compound in the track for the backing board.
Jason found the studs on the sidewalls before we placed the shelves in place, then he was able to measure how many inches from the back wall the stud was and screw the bookcases in every few feet. The side of the outer bookcase that abuts the second bookcase on each side are also affixed to each other. Then, Jason screwed ferring strips into the stud on top of the bookcase and screwed that strip into the top of each bookcase, so they are securely in place.

It took me weeks to pick out trim. I love trim…and all the options were overwhelming.

new trim unpainted

I had really wanted already primed molding, but I liked this one the best. It was classic enough yet had some detail.

new trim unpainted closeup
new trim unpainted
I brought a shelf to Lowe’s and they color-matched. I bought a quart of paint and painted the molding and the joint compound I had used to fill up the backing board track.
2 inch lattice
We used 2″ wide lattice to cover the ends of the abutting bookcases.
2 inch lattice 2
2″ wide lattice covers ends of abutting bookcases

We ended up being able to re-use the old trim that the girls and I had pulled off the wall as the baseboard. I also bought drawer pulls that fit the style of our room and, I feel, changed the style of the BENNO from modern to more traditional.

drawer handle
We felt the BENNO was too narrow, so the piece of alder we bought for the seat was deeper than the BENNO TV Bench. Jason built a brace on the wall behind the BENNO by screwing a 2″ x 4″ piece of wood into the stud so that the piece of alder could be affixed to that as well as the top of the BENNO. This makes the whole construction stronger.
pillow on bench
We felt 24″ depth was deep enough to sit comfortably and also be able to curl up and read a book.
finished 1
finished 2
One side holds Jason’s books for work and our homeschool books, plus boxes of our family genealogy research, books and photos.
finished 3
The other side holds mostly fiction, scrapbooks and some reference books.
finished 4
The window seat has become a well-sought after cozy reading nook.