Floor plan design single-family house with around 150 m²

If I may read from this that you don’t get annoyed every day about the "drywall instead of planning" aria in the bathroom, then that makes me happy. However, I have absolutely no impression that the window sill behind the sofa would effectively devalue your house. You didn’t have a bad outcome.

Thank you for the kind words. I can live with it too, but just wanted to say that it’s not exactly perfect for me. But I guess that always depends on the current life situation. Maybe in 10 years I will also find it completely okay. And you can do a lot with interior design to redirect the view elsewhere, so that it bothers you less and less.

This intermediate size is actually very uncommon for us. Why is that?

I thought that was a very common size? At least with all house-building companies and non-floor-to-ceiling windows, it was always this parapet height. Sometimes I know it with a few centimeters less, but actually it is a common height.

Maybe because you already need fall protection there, but not much more daylight comes in? No idea, Germany is also the country of standards and rules, even if they are not legally required, we like to stick to them. It's probably the Prussian heritage or something.

I thought that was a very common size?

means, I think, the 60cm.

Exactly 60 cm Either there are floor-to-ceiling or the 90 cm Fall protection on the upper floor is certainly necessary. On the ground floor probably not. In older houses, a parapet height of 40-60 cm is often seen. There were then small elongated radiators in front of it.

Yes, that's right, those low, endlessly long radiators under a windowsill. My father also has them in his condominium. They are on the upper floor but have a balcony across the entire front, so there is no fall protection either.

I absolutely cannot understand why anyone would place the sofa in front of a floor-to-ceiling window, especially when it is the "main window" to the garden. And then always face the wall with the ugly black hole (=TV) instead of looking out into the garden. Unless someone is an absolute TV junkie and is constantly watching. But hopefully, that is the exception in families with children. When we watch TV, we always lie comfortably in the corner of our sofa and have a perfect view of the TV from there. When we talk, we have the optimal view of the (evening-lit) garden and the fireplace. I also like to drink my morning coffee on the sofa while looking at the trees. Simply beautiful.

As a suggestion, here is a possible arrangement of corner sofa, TV, and fireplace.