Bunk Bed with Trundle Wood

Bunk Bed with Trundle Wood.

I'm not a big fan of high beds for kids, and that's the one but I see this option. My question is, is not it to waste space if you have a few square meters of room? Walls papered with floral motives and instead of putting bed, here we have preferred to put a bunk bed with trundle in an armchair, so when nobody sleeps it looks like a room and we have the possibility that another person sleeps in the trundle bed. However, I find them in turn fun, and also practices in space.