ᐅ Extending the Billy Shelving Unit with Drawers – Which Models Are Compatible?

Hello everyone,

I’m planning to expand my existing Billy bookshelf with additional drawers, but I’m not yet sure which models would be best suited for this. I’m especially interested in which drawer systems are directly compatible with the Billy bookshelf without requiring major modifications. I would also like to know if there are specific dimensions or construction types I should pay attention to—both for the width and depth of the drawers as well as for the mounting options.

Can you recommend which drawer models work best with the Billy bookshelf, where to find them, and what to consider to ensure the extension looks cohesive and functions well?

Thanks in advance for your advice!

Hello Carstengo,

First of all, it is important to know that the classic Billy bookcase is modular, but the existing shelves were not originally designed for built-in drawers. For suitable drawers, you should either look for IKEA’s own "Alex" pull-out system or special drawer boxes made to fit Billy dimensions.

The typical measurements for Billy are 40cm wide (16 inches), 28cm deep (11 inches), and 202cm high (79 inches), where the installation height for a drawer usually requires adjustment of the bookcase, since the shelves do not serve as guides. For stable drawer operation, it is recommended to install separate drawer slides mounted on the side panels.

Alternatively, there are third-party suppliers offering ready-made drawer inserts designed to fit Billy, available from specialized furniture retailers. These usually pay attention to the exact installation dimensions and recommend suitable sets based on the height and depth of the bookcase.

Recommendation: Before purchasing, always measure the exact internal dimensions of your bookcase and compare them, as differences can occur between older and newer models.

I have had good experiences with the original drawer systems from IKEA. The Alex drawers fit well under Billy, as long as the shelf is tall enough. Otherwise, just look for drawer boxes around 40cm x 30cm (16 inches x 12 inches), which usually fit.

Hello Carstengo,

I completely understand that you want to carefully consider this question. Many people don’t realize that Billy bookcases, due to their design, are not originally intended for installing drawers directly. That’s why it’s common to see the workaround of essentially dividing the bookcase into separate sections – for example, two or three compartments with fixed shelves and one lower compartment for the drawer.

The IKEA “Alex” series is actually quite compatible because it is designed with similar depths and widths. You can either place them next to the Billy bookcase or, in some cases, even insert them inside, but adjustments are usually necessary.

An important point is that the drawer slides are often missing in Billy units, which means you’ll need to install them separately – for example, with running rails from a hardware store or IKEA’s Komplement series. Be sure to measure the installation depth (standard is about 28cm (11 inches)) to ensure the drawers don’t stick out or are too short.

Hopefully this gives you a good initial overview. If you like, I can send you some links to suitable products or DIY tutorials later.

jeff65 schrieb:
For suitable drawers, you should either look for IKEA’s own insert system "Alex" or special drawer boxes sized to fit Billy units.

Thanks for the tip about Alex – do you think these can be inserted serially into a Billy shelving unit, or should they only be placed separately next to it?

Jeanbar schrieb:
You often see the trick of basically dividing the shelving unit into separate compartments – for example, two or three sections with fixed shelves and a bottom compartment for the drawer.

That’s an interesting approach. Does anyone have tips on how to ensure stability when modifying several compartments? Are there product names for the guide rails you mentioned, or recommendations for easy-to-install systems?

I’m also curious about the best way to carry out such a modification if you’re not very experienced with DIY.

Billy bookcases were originally designed without drawers, but there are several options for adding them.

Regarding compatible drawer systems:
- IKEA Alex drawer units can be placed next to or under a Billy bookcase (minimum shelf height 116 cm (46 inches)), but cannot be inserted directly.
- Some third-party suppliers offer custom drawer inserts for Billy with matching wooden guides and metal runners, which can be integrated into the bookcase structure.

Technically, sturdy drawer slides are needed, usually called full-extension slides. These are mounted on the inside sides of the bookcase, requiring an internal clearance of about 16–18 mm (0.6–0.7 inches) per side.

For users with less DIY experience, I recommend first measuring the internal dimensions precisely, then purchasing modules that fit as closely as possible and come with the necessary slides included. Instructions and videos can help with assembly.

Important: Modifying the bookcase changes the load distribution, so consider reinforcing it with additional back panels to ensure stability.