How To Turn An IKEA BILLY Bookshelf Into A Corner Unit

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If you're looking for a budget-friendly hidden gem at IKEA to tidy up your space, the BILLY bookcase system — specifically the corner unit option — might be the most overlooked solution. IKEA sells a dedicated BILLY corner unit with two extension wings, or you can make your own with three standard BILLY bookcases and a simple hardware kit. As one of several creative IKEA shelf hacks that are entirely unique, it's not just a clever way to maximize a dead corner in your room, it's also a satisfying weekend project with a tidy, custom look. As shown in viral videos, installing the inexpensive corner brackets that pull this clever bookshelf triangle together is a simple operation with just a few instructions. In the end, this is the kind of small-space IKEA hack that delivers big on both form and function.

To replicate the corner look that's driving designers wild, you'll need three BILLY bookcases, two standards and one narrow, plus the IKEA BILLY corner hardware kit (also available on Amazon), which includes the brackets and screws. Or, again, you can buy it all together as IKEA's BILLY bookcase corner combination with extension units. You'll also want a drill or screwdriver to put all of the separate pieces together. Since this DIY uses actual IKEA parts sold in-store, there's no guesswork or custom cutting needed, and the result looks just like something out of a designer showroom.

Creating a corner bookshelf with IKEA's BILLY bookcases and the matching bracket kit is a lot easier than it sounds, thanks to YouTuber Kate's (@afkatey) simple step-by-step demonstration. She shows the full process using two standard BILLY bookcases and one narrow BILLY bookcase, all assembled as usual. Once the units are built, the first step is arranging them in the desired corner space to visualize how they'll fit. After that, she lays the bracket kit flat on the ground, positioning it where the shelves will join.

From there, Kate carefully lifts the two adjacent bookcases and places them onto the bracket, aligning them with the hardware on the floor. She repeats this process with the other side, completing the L-shape on the bracket. Then, she uses the included attachment hardware to secure the shelves together at the top, keeping everything sturdy and flush. Once everything is linked, she and a helper carefully move the full unit back into the corner where she wants it. The result is a sleek corner bookshelf that looks built-in, but only takes a few minutes to set up. Kate emphasizes safety in her video, noting that it's smart to ask for help with the lifting steps. But overall, the process is fast, foolproof, and requires very little effort to pull off, making it a perfect DIY for any renter or beginner. Need more ideas? Here's how we'd use the IKEA BILLY bookcase in every room of the house.

Once your bookcases are assembled and connected, you could take things further by customizing them to better match your space. Many IKEA fans choose to paint the units, add molding, or even install LED strip lights to elevate the finished look. Because the BILLY is made from particleboard and veneer, it's relatively easy to work with if you want to add design touches like wallpaper on the back panels or handles on the sides. Even just anchoring the whole unit to the wall can make it feel more like a built-in bookshelf than a modular kit.

But you don't need to go overboard to get a clean, stylish result. Kate's video proves that using IKEA's own bracket kit — rather than trying to engineer a DIY solution from scratch — makes a huge difference in how stable and seamless the corner unit looks. It's also more affordable than most people realize. If you already own some BILLY shelves, it may cost less than $30 to get the brackets and finish your corner unit. That makes it one of the most cost-effective IKEA hacks out there for maximizing storage without losing space. 

Whether you want a minimal, modern corner shelf or something more decorative, this underrated IKEA bracket kit opens up a ton of possibilities, and all without needing power tools, advanced skills, or major spending. If you're happy with the result, here's another simple IKEA BILLY hack that will tidy up your cluttered closet.