First conversation with the developer - first numbers...

Kaho: No, on 3 floors. End-terrace house from 1921. 10-20m2 more would have been nice to have, but it suits us as it is. The alternative would have been to continue renting. However, we still have a basement, a garage, and a solid shed. Previously, we had a 98m2 rental apartment on one level with 2 storage rooms and a basement.

Will write more later, have to go to work now.

Please stay on topic. It was not about the floor plan. It was about the realism of the numbers from T and C. I am now assuming that our questioner has read what he gets from T and C for the sums mentioned. He has already taken some special requests into account in the To Do list for T and C. So... please, if we take seriously that it is supposed to be a middle of the road house without frills, where is the real catch in T and C's numbers? Not 1,000-2,000 but let's say 10 to 20 thousand too little. Where exactly? I don't see it. And one more thing regarding T and C and cheap. What is the name of the prestigious solid construction builder again? Vielbock? What is different about the substance there? Not the shiny stuff! Do they have stickier mortar? Or better stones? Or more cement in the screed? Or a premium PVC for the windows? Or stainless steel gutters? Or mahogany roof trusses? Karsten

However, we still have a basement, a garage, and a solid shed. Before, we had a 98m2 rental apartment on one level with 2 storage rooms and a basement.

But that is precisely a significantly different starting point...

Space requirements are very subjective, but from what I know, with two children, 140m2 + basement is already borderline. It can be done, but for example, there is no office; everything is distributed throughout the house, etc.

Where is the real catch with T and Cs numbers? Not 1000-2000 but say 10 to 20 thousand too little. Where please? I don’t see it. And one more thing about T and C and cheap. What is the name of the luxury solid builder again? Vielbock? What is different in the substance there?

I don’t see a catch in the substance of the house either. But the utility room / HAR with 5m² does not work in reality. Especially not for 5 people. That is the catch.

I also doubt the headroom in the attic for the house size. Exact measurements are needed for that but I don’t think it is planned.

However, we still have a basement, a garage and a solid shed.

Sorry, but the comparison is simply ridiculous.

What is this really about anymore? Another competition about who can build the cheapest or what can be imposed on others, how small or how much they can limit themselves, or is it still about the original question of the OP, whether they need some buffer for their desired standard and if so, what kind?