DIY Built In Bookshelves Using the IKEA Billy Bookcase Hack

Step 1

To get the Billy bookcases as flush as possible to the back wall, remove the baseboard. Use a utility knife to cut along the caulk lines of the baseboard. Then, use a claw back hammer and a small pry bar to pull the baseboard away from the wall.

Step 2

Assemble all of the boxes of the Billy bookcases, including the top extension. Leave the bookcases without the thin backing that comes with them since the back wall will become the bookcase backing since you’re building them in.You can keep the top extension off until after you anchor the bookcases to the wall.

Step 3

Since the bookcases are designed to have a backing (but it’s best not to have one in a built-in to allow access to outlets), there will be a small bap at the back.To make this look seamless, measure the bookcase and cut a piece of 1×2 board. Attach the 1×2 to the back of the bottom of the bookcase with the finish nailer.And the gap is gone! Caulk will fill any cracks later.

Step 4

Measure your wall and make sure the bookcases are centered and place where you want them. Anchor the middle bookcase.

Step 5

Use your clamps to tightly hold together the sides of two bookcases. Then, screw the wood screws through both sides of the bookcases to secure them to each other.

Step 6

See that little bit of space around the sides and top of the Billy bookcases? We want to fill that in to make the bookcases look like built ins.

Step 7

In the small gaps, drill 2x4s to the wall and the side of the Billy bookcases. Do the same for the top of the shelving unit too.

Step 8

To make the bottom of the bookcases look like one solid built-in piece of cabinetry, attach 1×4 pre-primed boards with finishing nails.Use a coping saw or jigsaw to cut out the sides of the boards to mimic the shape of the baseboard on the wall. It doesn’t have to be perfect as caulk can later fix imperfect cuts. Repeat the process for the top of the Billy bookcases, coping the sides of the 1×4 boards to fit the crown molding.

Step 9

Since the sides of the bookcases typically aren’t the exact width of a board, measure the gap between the bookcase and the wall and cut down the 1×10 board to fit as the face on the sides using a circular saw or table saw.

Step 10

Use the finish nailer again to attach 1×2 boards to the fronts of the bookcases to hide the cracks where the bookcases meet together.

Step 11

Use Loctite foam to fill any larger gaps. We used it to fill the small gap between the bottom 1×4 and the bottom of the bookcases since it was slightly too big for caulk. Once dry, cut the foam and sand it smooth.Use caulk to fill any cracks between the wall and boards.Then, use wood filler to cover any nail holes or cracks in the boards where they meet. Let dry.

Step 12

Once all of the fillers are dry, use an orbital sander to smooth it out.

Step 13

Use a shop vac to remove any sanding dust from the built ins to make it ready for paint.

Step 14

Paint all of the visible boards with the satin paint you had matched to the bookcases to make everything look like one solid piece of built in bookshelves. You don’t have to paint the Billy bookcases themselves, just the boards so they’ll match them.

Step 15

Add glass/panel Oxberg doors to the front of a few of the bookcases to provide some concealed storage. Oxberg doors are designed by IKEA to fit Billy bookcases, but by making these built in, there’s a trick to hang them properly.

Step 16

Since the existing holes on the Billy bookcases are no longer useful for hanging Oxberg doors as they are intended in design, you have to make new holes to account for the depth of the 1×2 boards added to the front of the bookcases.Place a combination square against the 1×2 and mark its depth with painters tape.

Step 17

Use the marking on the combination square to mark new holes closer to the front of the bookcases.

Step 18

Place your drill bit inside of an existing bookcase hole. Use tape to mark where the hole stops so you know how far to drill the new holes.Drill into where you marked for the new holes to that depth.

Step 19

Screw the door hardware into the new holes you drilled, and attach hinges to the doors.

Step 20

Hang the Oxberg doors to the bookcases, and check to make sure all doors on the built in unit align properly. Then add pulls or knobs.