ᐅ KALLAX Installed Under the Window Sill – Space Issues?

Hello everyone, I am currently facing the challenge of installing a KALLAX shelving unit from IKEA directly under my window sill. The shelf is 147 cm (58 inches) tall, while the window sill in my room is only about 110 cm (43 inches) above the floor. My question is whether it really makes sense to place such a large KALLAX unit under a window sill without affecting the window’s functionality or causing significant space issues.

My window sill is relatively deep, about 30 cm (12 inches), and the room itself is not very large. I am especially interested in practical experiences – how have you handled this? Are there any tips or tricks to make good use of the space despite having a shelf this deep under the window sill? Or would it be better to choose a smaller shelving unit to avoid potential problems with height and depth?

I look forward to your opinions and experiences with installing KALLAX under a window sill – any space problems?

Enrica schrieb:
I am particularly interested in practical experiences on how you managed this – are there any tips for making good use of the space despite having such a deep shelf under the windowsill?

Hello Enrica, in general, it can be said that installing a KALLAX shelving unit beneath a low windowsill is definitely possible, but it greatly depends on the height of the windowsill and the room layout. If your windowsill is at 110 cm (43 inches), you could theoretically choose a lower KALLAX module (e.g., a 2x2 or 2x4), which usually measures about 77 cm (30 inches) or 147 cm (58 inches) in height. However, the 147 cm (58 inches) module is actually too tall if you want to build directly underneath it because the windowsill would then rest above the top compartment.

Enrica schrieb:
…or it causes significant space issues.

An important detail is whether the window needs to be fully opened and how deep the windowsill is. A very deep sill combined with a deep shelf can make access difficult because you have to lean over the shelving unit.

My advice: Measure precisely how deep the windowsill is and base your decision on how much space you can allocate to the KALLAX without restricting the window opening. A cut-down or custom-height shelving unit might also be a solution to adjust the height accordingly.

Hope this helps you a little as a starting point!

Josan schrieb:
Maybe a cut-down or custom-shortened shelf could be a solution to adjust the height.

That’s brilliant! 🙂 I also installed my KALLAX under the windowsill, but mine is a 2x2 unit that I shortened by about 10 cm (4 inches). This way, it fits perfectly under the windowsill without losing any storage space! I used the deeper windowsill as a shelf – very practical and it looks great!

Enrica schrieb:
Are there any tips to make good use of the space despite such a deep shelf under the windowsill?

My tip: use baskets or boxes in the KALLAX compartments to keep things tidy and make the best use of the space. You can also add lighting underneath, so the area doesn’t look so dark. It’s amazing what you can do with a small space! 🙂

Enrica schrieb:
My question is whether it really makes sense to install such a large KALLAX unit under a windowsill without affecting the window’s functionality or causing significant space issues.

Here is a detailed assessment: A standard KALLAX unit with a height of 147 cm (58 inches) is usually much too tall for a windowsill height of 110 cm (43 inches). While the bottom part of the window remains free, the shelf under the sill will be so high that either the windowsill rests on the back of the unit or the sill would have to be removed or modified. This can cause both aesthetic and structural problems.

Technically, there are two scenarios:

1. You install the unit so that the windowsill fully rests on it. Then the load of the windowsill is transferred to the unit – which must be securely fixed. This can work but requires more effort. In addition, the unit often prevents the opening of tilt-and-turn or casement windows because the window cannot fully swing inward.

2. You have to remove the windowsill or install a narrow cover. In this case, the typical “under-windowsill shelf” look is lost, and the entire side appearance will need adjustment.

Josan schrieb:
Possibly a sawed-off or custom-cut unit could be a solution to adjust the height.

This is probably the most practical approach – a custom-sized unit offers more flexibility and allows full use of the windowsill along with window functionality. Regarding depth, it’s important to measure precisely – windowsills with a depth of 30 cm (12 inches) are rather deep. You might be able to plan the shelf depth with a back stop so it doesn’t protrude too much.

In general, I recommend checking the window’s operation thoroughly before installation, especially to ensure the window can still be fully opened despite the unit. Otherwise, ventilation and cleaning could become problematic.

If you have more exact measurements or photos of the window, more specific advice can be provided. As a general rule, it’s advisable to choose the KALLAX so that it is at most 5 cm (2 inches) lower than the windowsill to avoid issues.