Ikea Billy Bookcase Hack- Built Ins

For my son’s room I wanted to add some bookcases to really ground the room and provide lots of spots for books. I want the shelves to look built-in, but do it on a budget. Enter the Ikea Billy bookcase hack! I bought the bookshelves for super affordably and then really customize them to look high end. Want to see how I made these?!

how to make the ikea billy bookcase hack- built ins

Let’s start with the video tutorial so you get an overview on what I did. Then, I’ll dive in with more details below:

 

If the video doesn’t work here, you can watch it on YouTube here. It’d mean so much if you’d watch the video! I’m trying to get better at my video skills so I can grow my YouTube channel. If you have a few minutes to watch this and/or subscribe, I’d so appreciate it.

billy bookcase hack

Last summer, I built my first Billy Bookcase Hack at my sister’s house. It turned out SO beautifully! That was a much bigger project since it was two bookcases high. But since we built that, I figured we could easily do a smaller version for my son’s room.

The bookshelves I’m building for my son’s room are shorter, but are also complex because of the fireplace and hidden storage. They could definitely be simplified by switching out the fireplace for a bookcase. But I think these details will be really special. Let’s get started!

SUPPLIES

Bookcases

• 1- Billy Bookcase 31.5″x79.5″
• 1- Billy Bookcase 15.75″x79.5″
• 2- Billy Bookcase 31.5″x41.75″

Screws

• 2-1/2″ Screws (to attach the lumber together)
• Cabinet Screws (to attach the bookcases together)

Lumber

• 4- 2″x4″x8′ Lumber
• 3- 2″x6″x10′ Lumber
• Shims (to level the bookshelf)

Trim

• 12′ of Baseboard Moulding (that we put upside down on the original baseboards)
• 12′ of Crown Moulding  
• 11- 1/2″ x 1-1/2″x8′ boards (used for the trim to cover the bookcase seams and fronts) 

Finishing Supplies

• Paint Brush
• Stickers to cover the Hardware
• Paint- Behr Winter White (to touch up paint on the Ikea bookcases)
• Paint- Behr Frosted Sage (to paint the trim)
• Outlet Spacer

Supplies for Hidden Storage

• Piano Hinge 
• 1 Plywood sheet
• Cat Art 
• White Melamine Shelving 
• Magnet for keeping art closed
• Library Battery Powered Light

step 1- figure out the plan

To begin, figure out the plan. To do that, measure the width of the wall that the bookcases will go on. The Billy bookcase comes in two widths: 31-1/2″ or 15-3/4″. Those same widths come in the 93-1/4″, 79-1/2″ or the 41-3/4″ height. So there’s 6 size choices. 

Note, on Ikea’s website they show more widths than I’ve listed, but it’s just multiple bookcases pushed together. So ignore those. They come in three colors- white, black, or birch. I’ll be using white.

Next, figure out how many bookcases can fit on the wall. Since our wall is 114″ wide, we’re going to use one of 31 1/2″ w x 79 1/2″ h bookcases, one of the 15 3/4″ w x 79 1/2″ h bookcase, and one of the 31 1/2″x41 3/4″ bookcase. That’s 78-3/4″ wide. That’ll give us 35 1/4″ for the fireplace (which I cover how we built here).

I sketched out the plan above. We ended up buying a second of the 31 1/2″x41 3/4″ bookcase to use as parts on the triangle portion on the bookcase.

Figuring out the height of the bookcases is important too. Our ceilings are 89″ tall. By using the 79-1/2″ bookcase height, this gives about 10 inches for a base and crown molding- both of which are important to creating a built-in look.

Note, the Billy also comes in a few sizes of extension units so if the heights of the existing bookcases don’t work, those might help.

step 2- build the base

Next, build the bookcases that’ll make up the built-ins. To build them, follow the instructions from IKEA for putting the Billy bookshelf together. By building it, this gives you the correct depth for building the base.

Next, remove baseboards on two walls- where the bookcase will be and the adjoining wall. We also had headboard and chair molding on the walls that we removed as well. Set the baseboards aside until adding on the trim (once the structure is built and the bookcases are in place). 

Why remove the baseboards? The front baseboard will be placed in front of the bookcase and will help it look super integrated into the room. The baseboards on the sides will need to be shortened to allow for the width of the new bookcase.

Now that the wall is prepped, let’s build a base. To do that, cut 2×6″ boards the same length as the room. Our wall is 114″ so we cut that length of pieces for the front and back and 8″ long pieces for the cross supports. Attach all four pieces together with screws.

The base will elevate the bookcases off the ground so they’ll fit floor to ceiling on the wall. It’ll also give support to the shelves and a place to attach baseboards for that built-in look. 

If needed, remove the flooring where the bookcase base will go. Since we have laminate floors, those aren’t supposed to be under anything built-in. So we used a Dremel to cut them so the base will sit on the original flooring. This way, the base can be built directly onto the subfloor and will be much more secure.

To make the base super sturdy, we added in 7 pieces of support boards into the inside of the base. The supports are placed at the end of each bookcase and then evenly spaced so there’s a support at each end of each bookcase and one in the middle of the wider bookcases.

The last, and especially crucial step of creating the base of the IKEA Billy Bookcase Hack Library is to make sure it’s level. Our house is old so this was tricky. Where the floor isn’t level, we added shims below the base to level it.

step 3- side support

And now, place the IKEA Billy bookcases on the base. Our project is a little tricky because the ceiling angles in on our old house. So the bookcase on the right side is a shorter height to work with the slope.

Next, use screws to attach the two bookcases together.

Since the base is complete, start building the side support. This isn’t necessary for the structure, but because of the spacing of our angled wall, it made the most sense to have a bit of space on the side. This made it so the tall skinny bookcase didn’t need to be cut down for the angled wall.

Cut 2 pieces of 2×6 the same height as the angle of the ceiling. Screw the back piece in the wall and then use 2×4’s to attach the front piece of 2×6 to create the side support.

The bookcase can then be screwed into the side support to stabilize it.

step 4- top support

Next, cut 2×4’s to the length of the top of the bookcases. Use a stud finder then screw the the 2×4 into a stud in the wall. This top support is important to the structure and it will provide a surface for the crown molding to be attached to.

Cut support pieces out of 2×4’s and screw them on top of each edge of the bookcase and one in the middle too. Then, screw on the front 2×4 into place

Finish up by using screws to attach the bookcases to the top support. Do this through the top of the bookcase into the 2×4 top support.

step 5- build the angled bookcase

The bookcases are all looking good, but the triangle above the right bookcase needs to be custom built.

Begin the angled bookcase by cutting a piece of the Billy bookcase on an angle. Screw that into the bookcase next to it. Note, we found it to be the most affordable to buy a second of the small Billy bookcases to cut up for this project. Plain melamine boards would have cost more.

Then, cut a piece for the opposite side. Again, cut the top of the angle. Screw that into the side supports.

Next, cut a board that will create the third side of the triangle bookcase. Use screws to attach it into studs in the wall.

For the backer, we had to cut it into three pieces. Each piece needs to be cut at an angle at the top. Then, use shims behind the backer board so it can be mounted at the right depth.

Continue with each piece of the backer board until they are all in place.

Last, cut shelves to the correct width so they can be mounted at the same height as the shelves next to them. On the left side, we could use shelf pins since the holes on the Billy frame worked. One the right side, cut shelf brackets out of the melamine boards.

 

step 6- hidden storage

Now, above where the fireplace will be we’re adding in hidden storage. When I was planning this project, I saw. that most people close up the area above the fireplace and I thought- what a waste! So we’re going to use it!

To begin on the hidden storage, we nail in bead board to where the hidden storage will be. The wall used to have a dinosaur mural, but I was ready for that to be gone (my son isn’t as dinosaur obsessed anymore). So the bead board hides what’s on the wall.

To begin on the structure for the hidden storage, we cut 2×4’s and mounted them on the bookcase. This will be the shelf brackets and where we’ll mount the facing for the storage.

Once the shelf brackets are in, cut melamine boards to fit as shelves to span across each bracket.

 On the bottom bracket, we put another 2×4 across the front of the brackets. This will be the bottom of the hidden storage so we wanted a bigger surface to mount the plywood facing.

Then, over the front of the shelves we nail on the plywood front. The 2×4 frame works perfectly to attach this to.

To go over the opening, I had this piece of art in my storage. It’s a great size for this project and the back is framed in wood- so it’s very sturdy. We didn’t like the art for this space, so I had my son choose out different art. He loves cats right now, so that’s what he selected.

I had the cat art printed at FedEx as a color architectural print for $35. The paper is thin though and the minute I attached it with Mod Podge, it got a million wrinkles. It looks old and weathered, which I am trying to embrace. I covered the top with Mod Podge to seal the print and give it the look of an actual painting.

On the back, my husband uses a piano hinge to attach it to the plywood facing. That way it can open and close to cover up the hidden storage- so cool, right?!

Here is the hidden storage closed. It’ll look just like art over the fireplace, but will be a fun spot for hiding treasures for my son! Note, we also used a magnet on the side of the art so that it stays closed.

Once the hidden storage was done, we began work on the fireplace. Note, I wrote a separate blog post on that since this one is already so long. I also have a blog post on how I made the tile for the fireplace.

 

 

 

To finish the base of the bookcases, nailed on baseboard. There’s a few layers of different baseboard to get it tall enough to reach the bottom of the Billy bookcases.

step 7- finishing trim

Now that the fireplace is done, it’s time to install the crown molding! This was a little tricky because of the angle of the sloped ceiling, but my husband figured it out and nailed it up into place. The trim makes the bookcases really come to live and look built-in!

After the crown molding is installed, we started putting up the trim over all the seams on the front of the bookcase.

It’s a super subtle difference, but it’s nice to cover up the gaps and seams for a professional look.

The trim especially covered up the issues over the angled bookcase we pieced together.

The trim even went over the shelf fronts. This made it so I’d be able to paint all the facing to have a uniform look.

Once all the trim is installed, I start on finish work. I fill all the holes with wood filler and then sand those smooth. In all of the seams, I caulk.

Then, once that’s done, I paint everything. For this project, I’m using Frosted Sage by Behr.

The only place I painted the laminate IKEA bookcases is on the side. I wanted the side to be the same mint color. So for that, I primed with two coats of slick stick before painting the mint color. That should keep it from scratching, but it’ll also have very little wear (as opposed to if I tried to paint the laminate shelves where books will come on and off everyday).

To finish off the detail work, I added stickers over the screw and shelf holes. It’d probably be better to fill them with wood filler and sand and paint, but using stickers over the holes is so much faster!

step 8- outlets

Finally, let’s talk about electrical with the bookcases. For the outlet in the bottom back of the bookshelves, we used a spacer so that it’s be pushed out to sit flush with the backing on the bookcase. Pretty simple. It’s still usable which is good because there’s not many outlets in my son’s room.

For the light switch that used to be where the bookshelf is, my husband built a box for it and flipped it so that turns on outside the bookcase. It’s super convenient. 

I painted the box Winter White by Behr as that was the best match I could find to the inside of the Ikea Billy bookcase.

Here’s a look at there the light switch is now. We love the new location!

after

After weeks of working on this project, here’s how it turned out. I’m so proud of these bookcases!

They add such a presence to the room. They’re cozy and absolutely ground the space (which was the goal from the beginning).

At night I turn on the fireplace as I read to Don and it’s SO warm and cozy. This is an electric heater so it does warm up the room.

One detail I really love is the art on the shelves. Over a month ago when I started planning this project, I bought mini canvases from the art store and each weekend Don would paint a different piece of art for the shelves. Each piece of art if focused on a different color and he painted some of his favorite things.

This was a very fun project for both of us and I think he’ll like having his art on display!

The books on the shelves are both books we’ve had for ages and some I’ve been slowly collecting of classic kids books printed as really beautiful editions. I have a bunch of these gorgeous classic kids books linked here.

Here’s a picture of the hidden storage open and closed. I haven’t put anything in there yet. But I think it’ll be a great place for kid treasures! Having more storage in a child’s space is always nice!

I am so, so pleased with how this whole project came together! It feels special and interesting. And definitely like it’ll grow nicely with my son.

price breakdown

For this project, we spent $89 on the large Ikea Billy bookcase, $49 on the skinny bookcase, and $98 on the two small bookcases. Screws cost $25. I had the baseboard molding on hand. Crown molding cost $41 and the facing trim cost $61. The 2×4’s cost $16. Then the 2×6’s cost $38. Shims are $4.

For the finishing supplies, the white paint cost $7. I had the other paint on hand. Stickers cost $7. The piano hinge was $11. I had the plywood on hand. The cat art cost $2.40 to buy and then $35 to print it. The white melamine shelving cost $24. Outlet spacers are $9. The library light that’s battery is $35. And the magnet cost $6.

Total- $558

So there you have it, my latest Ikea Billy bookcase hack. What do you think of it? Do you think the hidden storage and fireplace were worth all the work they took? Do you like the books with the matching art? I’d love to hear in the comments! And thank you for reading. It means so much to me!

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