Single-family house 143 sqm - the perfect planning?

Children in their teenage years use it a lot... We were constantly hanging out on the balcony in summer.... What else were we supposed to do with our 14-16-year-old friends on the terrace with the parents?! And the children will also spend much more time in there over the years... So I think Manu's approach is good too!

But there is a difference between a room being 10 to 12 sqm with a normal ceiling height, and whether a good third of the 10 to 12 sqm is under 200 cm high.

So, I put together something and quickly designed something. The external dimensions should be the same. I only changed the upper floor to show how the upper floor could be designed differently. Wall thickness, etc., would of course still need to be adjusted, and with the master bathroom, you'd have to look into the drainage, which is not so optimal on the ground floor :-/

Do you actually have any clever ideas for the ground floor?

... first define what else could still change. Window positions, dormers, widths, heights of the house (what is the roof pitch, actually?).
Quickly turning a house that was originally designed for a maximum of one child into another house with your requirements is not that easy, as there are too many dependencies between the floors, stair locations, dormer locations, etc.

Is there really no possibility to still make a free house plan for the plot?

... first define what else could still change. Window positions, dormers, widths, heights of the house (what is the roof pitch anyway?).
Quickly transforming a house that was actually designed for a maximum of 1 child into another house with your requirements is not so easy, as there are too many dependencies between the floors, stair locations, dormer locations, etc.

Is there really no possibility to still do a free house design for the plot?

Basically nothing except the walls, the outer frame is as drawn. So I am aware that the scope for design is limited. The house is planned within the building envelope and generally, with the plot size, not much more is allowed. But we will first talk to the architect in the next few days and keep you updated.

Does anyone have experience designing the stairwell partly out of glass to make it appear more open? I find little information online about experiences/costs etc.

That means, window positions are not changeable either? Then unfortunately, there is nothing to be done with the manuscript OG idea either.

You really should review your room program together with the architect. I think the expenses for a house that is going to be newly built anyway are too high to have to make so many compromises.