ᐅ Adding Shelves to BILLY Bookcase – Which Replacement Parts Are Compatible?

Hello everyone,

I have a Billy bookshelf from IKEA and would like to add extra shelves. Unfortunately, I can only find original replacement shelves in the store, which are often expensive, and sometimes the dimensions or mounting details are not entirely clear. My specific question: Which replacement parts or shelves fit technically and in terms of mounting exactly (1:1) into a classic BILLY bookshelf? Are there compatible alternatives from third-party manufacturers that are both high quality and precise in fit?

It would also be important for me to know whether the standard dowels or shelf supports are standardized, so that regular shelves can be used with suitable brackets.

Thanks in advance for the tips!

Basically, the shelves of the BILLY bookcase are about 28 mm (1.1 inches) thick and are sized with IKEA’s standard widths. The thickness of the shelves varies depending on the model, usually around 1.6 cm (0.6 inches) for the shelf itself.

LIBUPO schrieb:
Which replacement parts or shelves fit technically and in terms of fittings 1:1 into a classic BILLY bookcase?

The original shelves have pre-drilled holes for dowels that fit IKEA’s typical adjustable shelf supports. Some third-party suppliers offer universal shelves, but these usually do not have pre-punched holes and require drilling.

I recommend using the exact dimensions of the bookcase and not deviating from the standard width and depth, as this can compromise stability.

Additional information:

BILLY shelves typically have a shelf thickness of about 16 mm (0.6 inches) and often a depth of 28 cm (11 inches) for the narrower model or 40 cm (16 inches) for the wider version. They are usually attached using small plastic or metal brackets that fit into the drilled holes in the shelving boards.

nubar schrieb:
Third-party suppliers sometimes offer universal shelves, but these often do not have pre-drilled holes, so you have to drill them yourself.

Drilling the holes yourself afterwards is a common solution but should be done carefully to avoid compromising the load-bearing capacity. The most reliable option remains using original accessories or custom-made shelves that exactly match the existing drill holes.

Here is a brief guide for anyone looking to add extra shelves to the BILLY bookcase:

1. Determine measurements: The interior width of the shelf can vary depending on the model, for example 40 cm (16 inches) or 80 cm (31.5 inches). Important dimensions are width x depth.
2. Shelf thickness: IKEA often uses 16 mm (5/8 inch) particleboard with a melamine coating.
3. Drilling: The original shelves have holes at specific locations. The hole placement is crucial for compatibility with the shelf pegs or dowels.

If you want to drill yourself, I recommend using the drilling patterns from IKEA as a template. Important: Check if your replacement shelf has the same thickness to avoid loose fittings.

Overall, I advise ordering replacement parts directly from IKEA or alternatively having shelves custom-cut and adjusted by wood suppliers.

Original BILLY floor supports are standardized, so you need standardized drill holes. Alternative boards must have these fittings or be re-drilled.

There is no other way; otherwise, the shelves will fall out.

A question for the community: How reliable is it to work with third-party flooring, even if you drill additional holes?

Nabla64 schrieb:
If you want to drill yourself, I recommend using IKEA’s drilling templates as a guide.

That sounds logical, but I have heard rumors that load-bearing capacity can suffer from incorrect drilling, especially with thinner or softer materials. Who can share firsthand experience on how stable alternative flooring really is when not using the original?