
Today is all about our IKEA Billy Bookcase Hack. How we turned IKEA’s Billy Bookcases into a wall of built-ins!
After moving in to our home, we wanted a wall of built-ins installed in our den. I got a bid from the cabinet shop that did our cabinets, and it was way out of our budget. So, I started googling DIY options. I came across a few IKEA hack wall of built-ins and decided that may be the perfect solution.
After researching and reading tutorials, we came up with a plan.

Executing Our IKEA Hack Plan
We started with a blank wall measuring 141″ wide with 9′ ceilings. We removed the baseboards along this wall and saved them to re-attach later. My husband is an electrician, so at this point he did all the necessary wiring to be able to install the lighting after the built-in is complete. If you are wanting to have hard-wired lighting, this is where you want to call in an electrician.
Materials Used For IKEA Hack
We purchased and put together the following IKEA Billy Bookcase items: (4) Billy Bookcases 31.5″x79″x11″ (4) Billy Bookcase Height Extension 32″x14″x11″ (8) Oxberg Doors.
Find the bookcases here . Click here for the height extension. Find the doors here . The height extension simply adds height to your bookcase. We have 9′ ceilings, so we wanted a tall bookcase. This may or may not be the case for you!
Other items we used: 1×10 MDF trim for top; 1×6 MDF trim for sides; 1×4 MDF trim for between each shelf; 2x4s & OSB crown molding for top; 5 1/4″ crown molding; Benjamin Moore Simply White paint in eggshell for all of the trim pieces; caulking & nail filler. Everything is linked at the bottom of the post.
Tools used: compound miter saw; table saw; drill; nail gun & compressor. Everything is linked at the bottom of the post.

We then built a platform for the bookshelves to sit on to make the 1st shelf even with the 6″ base molding we removed and will put back on later.

Next, pieces of wood trim were attached to both walls and the ceiling. We used screws where we could hit wood, and sheetrock anchors where we couldn’t. This wood trim will be used later to attach the finish trim to.

The bookcases are then installed on top of the platform. (You can see the wood piece mentioned in previous step above.) We evenly spaced the bookshelves so the trim pieces would be equal between each shelf as well as against the wall.
The spacing between the wall and bookcases is bigger than the spacing between each shelf (and obviously will be different for everyone depending on wall size,) but what is consistent is the measurement between the left bookcase and the wall and the right bookcase and the wall, as well as the distance between each shelf.

Here you can see all 4 of the bookcases evenly spaced along the wall.

Next, we installed more trim pieces to the top of the newly installed bookcases. This is so we can attach 10″ finished trim to it later. Same idea as the pieces of trim shown earlier.

At this point you will want to cut out any light switches and plugs you may have covered with the bookcases.

Here you will see where all of the wood trim pieces we secured to the wall, top of shelves and ceiling are coming in to play. The 10″ finish trim piece is installed on top. The piece still showing above the 10″ molding will be covered by crown molding later.

Another view of the finish trim on the top and sides. The gap between the wall and the 6″ trim piece shown here will be caulked.

Shown above is the 4″ trim piece that will be installed between these two shelves.

The unfinished wood trim piece shown above is installed so the doors will sit flush. (You can also see in this photo how the bookshelves are attached to the platform.)

You can now see what the built-ins looked like before any caulking, wood filler, crown molding or doors. I do want to mention a trim piece that I do not have a photo of. The front of each shelf pictured above got a trim piece as well. This is so the top of the doors wouldn’t have a gap. We used wood filler and sanded quite a bit so it appears to be all one piece.
I do have a video of this saved to my IKEA Hack highlight on my Instagram page if you have questions about this portion.

And here is the almost finished built-in. We filled all of the holes that come pre-drilled from IKEA to make it look more custom. This obviously means we will not be adjusting the shelves. You can do this part or not. Our shelves are roughly 13″, 18″, 18″ apart. We filled the holes with this.
We caulked everything and painted everything except the doors, back of the bookshelves and the actual shelves. We painted it with Benjamin Moore Simply White. I cannot tell the difference between what we painted and didn’t. (We used a Zinsser primer before painting.)

The after of our IKEA Billy Bookcase Hack ! The last thing was to install these Brass Swing Light Sconces and style the shelves! Like I mentioned above, there is a highlight saved on my Instagram page that may also be helpful if you are doing something similar. And as always, feel free to reach out with any questions you may have!
*One question I have received a lot of is regarding the doors and hanging them. We did have to drill new holes, because of the added thickness of the trim we added. We adjusted for the extra depth, and used the screws they gave us to drill into the cabinet in a different spot. However thick the wood is on the front, you will move the new drill hole that amount.
Update- I have written a FAQ IKEA hack blog post. You can find it here: IKEA Billy Bookcase Hack: The Most Frequently Asked Questions
Read all about how I style these shelves here:
Update Your Shelves With Some New Artwork
How To Decorate Shelves & Bookcases: 7 Simple Steps
8 Items To Use For Simple Shelf Styling
MORE INSPIRATION FROM THE SOMMER HOME:
Small Bedroom Makeover Before And After Photos
Our Living Room Sectional (Pottery Barn Pearce Sectional)
Find sources for the items we used (+ similar) here:
Find sources for my den here:
(disclaimer: when you shop through my links, at no additional cost to you, I may receive a small commission. I appreciate your support!)
A MA ZING!!!! Congratulations
Thank you so much! Glad you like it!
Wow! Love all the details you provide! Looks beautiful ?
Thanks so much, Charlotte! Glad you like it!!
Did you have to do anything with the hinges since the trim makes the doors sit out further? Its beautiful!!
Thank you, Kathy! You know, I don’t recall that we did anything different with the hinges than we would have if we were putting a regular book shelf together. When I open the cabinet, the hinges look like they come pre-set in the door and that is where they are now. And it appears we just drilled in to the cabinet like you would normally. I will ask my husband about it and get back to you if that isn’t right. Thank you again!
Hi there, we’re taking inspiration from your tutorial and have the same question. Did you use the predrilled holes in the bookcase to hang the doors or did you have to make new holes closer to the edge so they sit out from your new vertical trim pieces? Thanks!
Hi there! Last paragraph addresses this question.
https://thesommerhome.com/billy-bookcase-hack-tutorial/
How did you put the lights in? Are they electrical? Or battery powered? Bluetooth??? I’m looking for lights to put in my built in bookshelf and want something I can control with my phone or a remote.
Hi Michelle. At the top of the tutorial you can see a photo with wires coming out of the wall. I also talk about installing the wiring at that point (first paragraph or two.) We do have a light switch for the lights, but we also control it with our Alexa on our phones. Hope this answers your question! Let me know if not!
Beautiful! Is there a reason you didn’t purchase the Billy bookcase that includes the doors?
Hi Cheryl. I’m not sure I understand your question. If you are asking why we didn’t put glass doors on the top, we wanted it to be open shelving. And if you are asking about the bottom, they are IKEA doors. Let me know if this doesn’t answer your question! Thank you!
Sorry, I see they sell a unit that comes with doors on bottom, Billy Oxberg, so you don’t have to purchase separately.
No problem! Let me know if you have other questions!
I’m thinking, the reason they didn’t use the billy with bottom Oxford doors is because it would interfere with the ability to attach a trim piece between the bookshelves from top to bottom. The predone doors is flush to the edge of the bookshelf so, I can’t see how to use it while getting the built-in results. I could be wrong. I’m just guessing.?.
We did use the IKEA Oxberg Doors for this project. We just bought them separately.
The question regarding the hinges and doors was not answered. Can you explain further? This is a very important question. Ideas?
We drilled in to the cabinet just as you would do if they were regular Billy Bookcases. We just adjusted for the thickness of the wood we added. For instance, if you add a 5/8″ piece of wood, you will move the hinges out 5/8″.
Ok. I didn’t realize that the hinges could be adjusted that much so that the doors would not rub on the MDF facing piece. Thanks for your input.
It looks great! What sheen (satin, eggshell etc.) of paint did you use to match the bookcases?
Thanks
Hi Michelle. Thank you so much! We used eggshell sheen. Let me know if you have other questions!
Hi there! We were wondering how you built the top portion above the shelves, and fit flush with the ceiling. We are unsure how to drill into the wood to allow for the vertical support. Thank you so much!
Hi Ashley! We used Sheetrock anchors to attach the wood to the ceiling and side walls. And then we used a nail gun to attach the molding to that.
This looks very professional! I’m thinking of doing something similar (though less fancy!) with the Billy bookcases I have, do you have any tips on what to use as a platform base? And it may be a silly question, but how did you cut out the gaps for electrical sockets? I was considering drilling a hole and then using a small saw, I’m just not sure what’s best and don’t want to damage the backs as the backing material isn’t the most robust. Tia 🙂
Hi Charlotte. Thank you! My husband used a jigsaw to cut out for the electrical and a mix of 2x4s and plywood for the base.
Hi, i absolutly love your ikea built in hack, but i am having really hard seeing how you attached the doors when you’ve added an extra board onto the front. surely the original holes for door attachment don’t fit? is it possible you could explain it to me or show via. pictures?
thank you soooo… much. 😉
P.
Hi there! Thank you so much! Yes, we adjusted for the extra depth, and used the screws they gave us to drill into the cabinet in a different spot. However thick the wood is on the front, you will move it that amount.
Awesome tutorial! How did you attach the boards to the wall and ceiling? Did you nail them into the drywall or have to use anchors and screws?
Thank you so much! We used screws into the portions where we could hit wood, and sheetrock anchors on the rest.
Hey there!
I love what you guys did! I’ve been contemplating using some of Ikea’s ready to go units – but they just cost so darn much. Your tutorial has given me hope that I’ll be able to update my dining room much sooner than later! Did you guys use the backing that comes with the billy bookcase? I’ve seen other tutorials where they replace the back with a more robust material – but, I’m really hoping just the regular backs that come with them work great.
Thank you in advance!
Becky
Hi Becky! Thank you! We kept the backing! Happy to report it still looks great several years later! Let me know if you have other questions!
Hi-
Very excited to do this in my home – but I’m having a hard time figuring out where the book case extensions were installed. (I may be missing it – so sorry)
Are they at the top? Bottom? And how were they installed?
Thanks so much! It looks amazing!
Hi there. That is so exciting! The book case extensions were installed on top of the bookcase. It just extends the height of the bookcase. Let me know if this continues to not make sense!
You mentioned a trim piece that I you not have a photo of in the front of each shelf that got a trim piece. This is so the top of the doors wouldn’t have a gap. Then you I sed wood filler and sanded it so it appears to be all one piece.
You mentioned you have a video of this saved to your IKEA Hack highlight on you Instagram page, however I went to look for it and did not find it.
Hello! It is definitely there. In my highlight “IKEA Hack” it is currently 3/4 of the way through the highlight.
Are the bottom and the top the same thickness? We are stuck at this right now while building this unit.
I’m not understanding the question. Is the bottom and the top of what the same thickness?
Sorry, the bottom trim piece and the top of the doors trim piece (to avoid the gap), are those the same thickness?
Ours are not the same thickness, which I never realized until I just looked. Our top trim piece (to avoid the gap) is thicker, so when the door closes, it closes all the way just at the top if that makes sense. The top trim piece is the same thickness as the trim piece that runs in between each cabinet. The bottom piece isn’t as thick, but obviously doesn’t really matter, as you don’t see it. I’m adding a video to my Instagram IKEA Hack highlight with this info, if that would be helpful.
Thank you! We finished! I cannot believe it! Now the painting part. I have few questions:
1. What kind of finish did you use with simply white of BM, eggshell, flat, satin?
2. Did you paint all the shelves too?
3. Did you use caulking between shelves and the walls of the case?
We are almost there!
That is SO exciting! Congrats!!
We used eggshell.
Did not paint any of the added shelves just the shelf where we added the extra trim piece where the top of the door on ours is.
We did not caulk anywhere between the added shelves and walls inside the bookcase. Only the same part we painted that I mentioned above. That portion was caulked on the left and right, not on the back.
Looks great! How hard was it to paint the Billys? I’ve read about the nightmare of sanding and applying up to four-five coats. We are thinking of using the same Benjamin Moore white.
Thank you so much! We only painted a small portion of the actual Billy Bookcase- only the top of the 1st bookshelf and the inside of each shelf only on the left and right (where we attached molding.) The rest we left unpainted!
This a great DIY project. I am preparing to do this based on your tutorial. I have the 9′ H ceilings. What is the width of your room for that area? The wood trim you used at the bottom of the bookcase so the doors sit flush, what size is it?
How did you nail the MDF board between the bookcases? Is looks like the bookcase. Is it?
We are going to use the glass doors for the full bookcase with extension.
Thanks for sharing.
Thank you!
141″ wide
Our doors do not sit flush on the bottom of the bookcase, but they do on the top. We used the same depth piece as we did in between the bookcases, which is 1/2″
We used a nail gun for the project
Let me know if you have any other questions.
Good luck!
We have 10’ ceilings and are contemplating doing something like this. Do you think we could still make it work or would it look dumb with an extra foot of height? I’m assuming you can’t stack 2 extensions on the top of the units?
Hi Laura. I cannot see why you couldn’t stack another extension on top. You are securing everything to the wall, so it wouldn’t be a tipping hazard, so I can’t imagine why it couldn’t be done. You would need to take a look at them and see if it would physically work. I would definitely look into that first! If that isn’t an option, I would google bookcases with 10 foot ceilings and see if you can find images that would give you a good visual idea of that much extra space on top & bottom. Ours are 9′, so it would obviously be an extra 6″ of molding, and I’m not sure if that would look strange or not? Hope this helps!
Hello!
I am trying to make sense of the measurements.
The cabinets are about 80” tall. You have a 10” piece of trim on top, what looks like around 6” or so of trim on the bottom.
That would total about 96” total height, or 8 feet.
You stated your ceilings are 9 feet (ours are as well). Did you use a taller bookcase than the one you listed here?
Thanks!
Hi there! As mentioned in the material list, we used bookcase and height extenders.
New at all of this, how do you measure where to cut openings for wall plugs into the bookcases back piece and what did you use to cut it with?
Hi Angie! My husband used a multi-tool. He cut the hole the same size as the plug behind it.
Love this! Thanks so much for the inspiration! It might be a silly question, but how did you attach the trim between the shelves? (Picture 10 if you start counting from the empty room) – what did you use and which pieces did you attach them to? Thanks in advance! X
Hi Gemma,
You are so welcome! No silly questions! We nailed it to the front of the IKEA shelves, if that makes sense. Let me know if it doesn’t and I can try to explain it better!
Hello,
I’m going to build this beautiful bookcase hack but I live in France and I’m trying to find the paint color matching your “eggshell sheen”. Could you please give the reference & brand that you bought for yours?
Thank you very much and thanks again for your hack guide.
Joy
Sorry I just saw that you did give it. Benjamin Moore Simply White paint
Thank you 🙂
You are so welcome! Good luck with the build, and don’t hesitate to reach out if you end up having more questions!
Hopefully this is not repetitive as I tried to make sure it was not previously answered. What did you use to fill the holes on the side of the bookshelf? Additionally, when you mentioned that you only painted part of the bookshelf, were the interior sides part of what you painted? Or did you not need to even with the holes filled? THANK YOU!!
Love it! It looks great!
Hi Renee,
We used DAP DryDex and did paint the interior sides. Thank you so much! And let me know if you have any other questions!
Hello, looked so good my wife and I are currently building this as I type. We have the bottom complete and now are doing the added trim to make everything look flush. We are puzzled as to how the doors set once they are on. Can you take some pictures of your doors open, did you add a trim piece to the first shelf the doors close against?
Hi there. How exciting. I have an “Ikea Hack” highlight on my Instagram page that may be helpful. There is also a paragraph at the end of the blog post that may help? If not, let me know and I’ll see if I can explain better.
https://www.instagram.com/thesommerhome/
What doors did you purchase to cover the shelf?
Hi there. Doors linked under “materials used” section.
https://thesommerhome.com/billy-bookcase-hack-tutorial/
Hi I am in uk
I can’t source any paint or find any dulux or uk paint that colour matches the Benjamin Moore
Does anyone know what paint in the uk matches the billy bookcase i really want to finish this now
Thanks
Hi Matt,
I would suggest taking a door, or any other part of the bookshelf, to the paint store and see if they can color match it for you. Hope this helps!
Hi! Love this. Did you use the flat shelves that are part of the billy bookcases or did you use plywood and measure to fit it in? The reason I’m asking is because I have friends with the billy and the books they have are heavy and the shelf sinks in
ThNk you
Hi Deb. Thank you so much! Yes, we used the shelves that came with the Billy Bookcases.
Do you think you could save some time and just order the billy bookcase with doors already attached? https://www.ikea.com/us/en/p/billy-oxberg-bookcase-with-doors-white-s29281066/
We are planning on doing this in a room that only has 14″ of clearance between the wall and window. Did yours stick out farther than the bookcase original depth?
Hi Erica. We built ours against the wall.
What trim did you use on the bottom in the step “The unfinished wood trim peice shown above is installed so the doors will sit flush”. I am working on my built ins and I think I will need this in the same spot as yours because the bigger trim that covers the bottom is not sitting flush and it’s driving me mad!!!
Hi there. I don’t recall what it was called. We just went to Home Depot or our lumber store (can’t recall) with the measurements we needed to see what our options were and found it.
Curious if I can buy the Billy Bookcase with cabinets already. Would measurements you provided work the same? Cant wait to do this in our office/playroom! 🙂
Hi Erica! If you are asking if you can buy them with the doors already attached, no. They all come unassembled.
does the trim that covers in between each cabinet overhang each side and if so how far and does that affect the door hinges
Hi Gary,
I speak to this in the last paragraph of the blog post. Let me know if you still have questions after reading. Thanks!
Hi! I am going to attempt this using your instructions!! One question- where did you get the doors for the bookcases? Thanks!
Hi Sophia,
The doors are from IKEA too. Details are in the blog post!
Hello! First of all I love the hack! I would love to repurpuse my billy bookcase wall which is plane into what you did. Can you tell me if vertical trims are flush with the bookcases or have a lip? I have glss doors on a couple of my bookcases and have a hard time with picturing trim around the doors. Any advise and or pics of the hinges would be appreciated. Thank you in advance
Hi there. I have a highlight on my Instagram page that may help. Let me know if you still have questions after watching it! https://www.instagram.com/thesommerhome/
If you don’t mind me asking, how much did this project cost? (Not counting your labor)
It’s beautiful. And built in cabinets custom made are so expensive.
Hi there. I don’t mind you asking at all, but lumber prices have changed dramatically since we did this, so I would have no idea! (And, we unfortunately didn’t keep track of the cost when we did the project.) The material list is on the blog post though, so you could look up the IKEA costs and get a good idea of the large portion of the cost. Hope this helps!
Am I correct in concluding that you didn’t put a more substantial back on them? I plan to do this hack with existing black/brown billies I have around the house and want to paint them a navy blue (Hale Navy to be exact) and I think paint will soak into and destroy the back. Just trying to think this through.
Hi Beth. You are correct in concluding that. We kept the backs that came with the bookcases. We didn’t paint the backs though, so I can’t speak to how they would hold up being painted. Happy New Year!
Thank you! Happy New Year to you too!
Disregard my previous question. I just reread it and realized they sell extensions that you used. My apologies! Amazing post! Thank you!!
Hi again. Sorry didn’t see this comment before responding to last!
Nice job! Regarding the electrical sockets, did you keep them mounted as they originally were to the stud, or remount them to account for the thickness of the back of the shelves? Just thinking at the very least you’d need longer screws to re attach the covers to the utility boxes. THanks!
Hi Greg. Thank you! We used box extensions & longer screws.
Gorgeous. In a few years, you will probably need to paint the doors and shelves (that you didn’t paint originally). I’ve owned a few white Billy bookcases and after a few years they start to yellow (they turn beige, really). We had an old one and bought a new one to go with it, and it didn’t match at all.
Thank you so much!
Hi what color are your walls and trim? We are looking for a good white not cream or yellow for our walls and a good trim to go with. Thank you.
Benjamin Moore Simply White.
Hi,
The project turned out lovely! I’m planning on doing the same in our home and was wondering how long the process took?
Thanks
Hi there. We did the building of it all over the course of 2 days, and then took our time over the next two weeks on caulking, filling holes & painting.
Love this! I am wondering how high you made the base that you put the bookcases on? Did you just use 2/4s and 3/4inch plywood? Is the base total 6″ high? Was the base the exact depth of the bookcases or was it a little bigger?
Hi Phil,
Thank you! Base height will depend on your ceiling height as well as molding height. It is whatever you need it to be. If you look at the first few photos that should answer your question regarding the base depth and bookcase depth. The face is the same depth. And yes, it is made with 2x4s and plywood.
I am trying to figure out where and how you attached the Ikea Billy bookcase extensions. In the catalog they look like separate pieces from main bookshelf but I can’t tell in your pictures where and how you attached them to main bookcases. Please advise? Thanks so much for this tutorial.
They are attached to the top of the bookshelf. It doesn’t look like an attachment, it just looks like the rest of the shelf.
Hello! We are in the final stages of our bookcase build-adding the shelves in. I noticed the Billy bookcase shelf pins are silver and unsightly. I don’t see any in your pictures, it looks so much better. What did you use to hold the shelves in place? I can’t stand the silver pins!!! Thank you!
Hi there. How exciting! Ha ha we have the silver pins, but it doesn’t bother me! And ours are only on the first shelf? You can see them on my Instagram IKEA hack highlight. https://www.instagram.com/thesommerhome/
Hi! First, I love this built-in and want to attempt in my home office. My question is did you end up using the height extension pieces or did you decide to go with the wood to extend? Sorry if I missed!
Hi Yvonne! I apologize that I am just now seeing this comment! If you didn’t figure it out already, we used the height extension pieces.
Hi, nice job! My wife want the same now….
Which wood filler do you use ? After years you don’t have any crack ?
Thanks
Thank you! We used Dap DryDex to fill all of the holes, and we have had zero issues! Hope this helps!
Hi! Your wonderful tutorial was a big help with building a linen closet in an empty nook in my bedroom.
I want to note for others that may run into an issue regarding door placement: the doors for Billy bookcases aren’t meant to be stacked vertically — the upper door(s) will end up sitting higher than you think and therefore the pre-drilled holes that the hardware goes in (on the bookcase itself) don’t align with the doors. Our solution was to drill new holes 3/8″ above the existing holes and just attached the hardware a little higher.
This is probably confusing..but the big take-away is that the Oxberg doors aren’t meant to be stacked vertically…but there is a workaround!
Now if I can only finish aligning the dang doors…..IKEAAAAA.
Hi Jenna! Thank you so much for writing in with this! And I’m so happy to hear you found the tutorial to be helpful for your build!
I absolutely loved your tutorial. I am a DIY mom myself and had a question. Ikea sells the same bookcase in but in the height of 93-1/4”. Why did you purchase the bookcase in 78-1/2” then a heigh extender for an additional 14”? It’s basically the same size height. Thank you in advance:)
Hi there! Thank you! When we did this DIY, they didn’t sell the talker option!
The taller option is actually the shorter one with the extension.
What’s the thickness of the trim you installed to get the doors to sit flush? I see this trim is missing from the links to the supplies.
It’s the same thickness you use for the trim in between. In our case it’s 11/16” or .669” actual size.
Hi! What sheen did you use for the Simply White paint?
Eggshell