Separate niche with folding doors - closet space

Here in Germany, this is simply called a storage room.. (or also built-in wardrobe)

This translation gives a misleading impression; such closet spaces do take on the function of our storage rooms, but they are clearly much more than that. The "closet space" common in the USA is not only used for storage but is often employed as a walk-in wardrobe or even dressing room. In American architecture, these usually closet-like enclosed rooms are generally located in or near bedrooms and often have a size that we would already consider a room. Often the flooring (carpet in bedrooms) continues seamlessly from the main room into the closet. In the 4 different houses where I lived in the USA, I always had a closet space or walk-in closet in my bedroom, sometimes a small one of barely 2 sqm, sometimes a larger one of easily 12 sqm. None of them was even remotely similar to a storage room. However, it is quite possible that rather means a storage room. That remains unclear at the moment.

Or you can deal with components from cabinet systems (e.g. Pax, Ikea) and use these, either installing the carcass without a back panel or just the doors. Somehow, many things are possible there.

We also have a niche in the hallway that unfortunately did not have a sensible standard size. Using Pax and Platsa components and hardware store parts, I built a floor-to-ceiling built-in cabinet. Just be careful, with Ikea parts depending on the model, there is space inside. If custom drilling is necessary, you have to check if there is something to hold on to. That’s why the planned Metod doors did not work for me.

Here in Germany, it's simply called a storage closet.. (or built-in wardrobe)

.. and it's planned that way too: non-load-bearing wall with a room door.
I think the problem lies in the variety of doors and options you could have, but you have a clear idea.

Basically some kind of storage closet. (Dimensions: 135 x 110 cm) I absolutely did not want just one door that would then open towards the hallway (everyone has some kind of quirk!).

In the various apartments in the USA, we usually had clothes rods and shelves behind it but also the washer/dryer stack. Absolutely cheap design and served its purpose.

It will probably come down to a wooden frame (open at the bottom because of tripping) and mounting a hanging system from eBay on it… anyone who has done that before, please get in touch.
But I will get back to you right away @Musketier…

basically some kind of storage closet. (Dimensions: 135 x 110 cm) I definitely did not want a door that opens towards the hallway (everyone has their own quirks!)

Then a kind of vertical roller shutter like those known from old filing cabinets would also work.

We also have a niche in the hallway, which unfortunately did not have a practical standard size. Made from Pax and Platsa components…

Thanks, interesting, I would also like to keep as much depth as possible from the 110 cm, so that is currently not an option. Besides, it should be walkable at ground level. And that with you then not…
The carpenters and furniture stores I inquired about could also offer nice solutions, but did not give me any hope regarding prices…

I will try to find 2 sample images right away…