Floor plan design for a hillside house with 5 children's rooms

What do you expect? Lowest consumption values? Or is compliance with the energy saving ordinance enough. I imagine many children, lots of life in the house. Often doors open, windows open. Thirty cm Ytong plus lightweight plaster plus silicone paint top plaster, like with us, is certainly enough. Or similar. Save the 18,000,- and put it into the garden. Stones are less important than a nice garden. By the way, I think it's great that you are carrying out the project House for 7 without it becoming a palace. The plot looks nice too. Now get to it. Stop at 11 answers. Ask what the contractor can do and recommends, what his standard is. Then it will work and be inexpensive. And proper. Karsten

I also wanted to ask about the 30 cm exterior walls ... does that really fit?

Energy Saving Ordinance is enough for us! Thank you

The thing with the 30 cm exterior walls I also wanted to ask ... does that really work?

Yes, with Ytong it works. But you then need good windows and not too large glazing, then it can be sufficient to meet the energy saving ordinance. Our house has exactly this wall construction, purely monolithic. Many here build it like that. It is inexpensive and good enough. Karsten

Yes, exactly, we have planned quite small windows

Is building with 30 cm Ytong "okay," or does it have to be KfW55 with 36 cm stone and an additional 18,000?

Stop answering 11 times. Ask what the contractor can do and recommends, what his standard is. Then it will work and be inexpensive. And proper.

As far as one compares apples to apples (I assume here: both monolithic), it makes a difference for the experience of the processor whether one uses the usual stone or a different one – but not its thickness. For fulfilling KfW55, it may well be true that the 36.5 cm simply works, and with 30 cm one has to painstakingly comply with some side conditions (window surface ratios, etc.). What should be behind the difference of 18,000 EUR: surely not just the 6.5 cm more stone?