Single-family house - 150 sqm - 1.5 stories - despair

Can you... but of course, it should not be like that in any new building. I think you shouldn't build under 4m

…and that as a shell construction measurement. Minus plaster and base, only 3.6x cm remain. My sofa with 2.64 + 50cm left/right clearance is just as wide.

I'll also give my two cents. So the architect's floor plan is indisputable. Regarding the budget, I have to agree with the others that it won't be enough for everything (except the plot) given your wishes. So building a house is possible. Depending on the plot, maybe even including incidental construction costs, but certainly not including clinker bricks, KNX, two fully equipped bathrooms for divisibility, kitchen, etc. As for the price of the tiles, I see that more relaxed. We get well under €50/sqm material price and install them ourselves. So if you want to save there, it is definitely doable.

30€ is the pure tile price, but for that you don't get anything great

Of course, you can get decent tiles at this price - albeit not including installation by a tiler.

I think you shouldn't build under 4m

Apart from the resale value, there is little against building a small living room if you will feel comfortable in it.

My sofa with 2.64 + 50cm left/right clearance is just as wide.

The OP probably doesn't care how big your sofa is and whether it will fit in his living room. There are even cozy living rooms without a sofa. I find that the tone in this thread is becoming somewhat unfriendly and condescending.

There are even cozy living rooms without a sofa.

OT: Recently, there was a post saying that sofa seats are not healthy at all. That's why trendy people now sit on the floor with mats and blankets.

I think you shouldn’t build under 4m

I wouldn’t put it that way, but rather: a home should not be a downgrade compared to what you have as a rental apartment. I find this very popular living room minimum width dogma highly unnecessary. I alone have enjoyed apples several times this summer that had less than the “90-60-90” 65 mm diameter.