House purchase and house construction - What can we afford

That's clear already - but somewhere we have to start and at least to visualize what we basically want (if [Wunsch] were something for you) I think it's reasonable. Especially since there is still the option to sell the apartment - which would then massively increase the budget. Whether it becomes a City Villa or not is so far rather secondary in our imagination - we are pragmatically minded.

(...) We do not have a plot yet, but we have already gotten a bit into 1.2 new development areas. (...)

And on what basis are you planning if you do not even know what your field looks like, what height differences you have, what the cross-section is, where neighbors are, where the building plots are, where the street is, where a possibly specified access road is, where the house connections have to go, etc.?

Well, if you are so pragmatic, then it is all the more pointless to already discuss concrete floor plans now. As said above, think about the general room program as well as your everyday situations. What do you particularly like today (e.g. a long hot bath and then cooling down on a lounger), what bothers you today (e.g. "We actually like an open floor plan, but if one is watching TV and the other is working around in the kitchen, that’s really annoying"). What are must-haves (a closed office because of 70% home office), what are no-gos (basement bedroom, "that gives me claustrophobia"), etc. etc.

And in parallel(!) start looking for a plot (and for all I care also already an architect). Once you have a concrete plot, you can go into retreat with the found architects, the plot, your room program, and the everyday briefing. And only then with the preliminary drafts and a soil survey start looking for contractors / tendering (preferably carried out/accompanied by the architect or client advisor).

We prefer a prefabricated house because neither of us are specialists and we expect a bit more controllability with a virtually standard product (and also, when it comes to acceptance by an expert or similar, potentially easier assistance – who might also be familiar with the weaknesses of the individual providers).

Keep dreaming. The myth of a safe standard product is an advertising lie of the prefabricated house industry. A prefabricated house is basically neither better nor worse than a solid house. It always depends on the specific company, the actually involved craftsmen, and the site management. There are probably no fundamental weaknesses with any of the providers; a house in Germany must be safe and well insulated. With a budget provider, you will of course have to make compromises in some areas; then you get polystyrene instead of wood fiber and a few fewer sockets. Upgrading a budget provider to a similar standard as a more expensive provider usually costs more than just going with the supposedly expensive one from the start.

Regarding control, you also have some disadvantages with a prefabricated house. What happens in the factory is not inspected by your expert. The house arrives finished on the building site, and you have to rely on all vapor barriers being in order. A solid house can be easier in this respect. And don’t forget that with a prefabricated house, you have to make many decisions purely based on plans, whereas in solid construction you can still change many details (e.g., sockets) during the shell construction phase.

And on what basis are you planning if you don’t even know what your plot looks like, what height differences you have, what the cut is, where neighbors are, where the building envelopes lie, where the street is, where possibly a predetermined driveway is, where the utility connections need to go, etc.?

Well, if you are so pragmatic, then it is all the more pointless to already discuss concrete floor plans now. As said above, think about the general room program as well as your everyday situations. What do you particularly like today (e.g. a long hot bath and then steaming out on a lounger), what bothers you today (e.g. "We actually like an open floor plan, but when one watches TV and the other is fiddling in the kitchen, that’s really annoying"). What are must-haves (separate office because of 70% home office), what are no-gos (basement bedroom, "that gives me claustrophobia"), etc. etc.

And simultaneously(!) start searching for a plot (and if you like, also an architect). Once you have a concrete plot, you can go into retreat with the architects you found, the plot, your room program, and your everyday briefing. And only then proceed with rough drafts and a soil report to company search/tendering (preferably conducted/accompanied by the architect or building consultant).

Exactly – that’s actually what I wanted to say with floor plans. We see things we like and take them with us (whether it is the pantry as a passage between the house entrance and kitchen) or simply no bathrooms with two doors. At the same time, there are things like you shouldn’t come directly from the entrance area into the living room but rather around a corner, etc. Floor plan is indeed a very big word for that – let’s call it concepts.

Keep dreaming. The myth of a safe standard product is an advertising lie of the prefab house industry. A prefab house is basically neither better nor worse than a solid house. It always depends on the specific company, the craftsmen actually involved, and the construction management. There are probably no fundamental weaknesses with any of the providers; a house in Germany must be safe and well insulated. Of course, with a cheap provider you will make compromises in some areas, then you have styrofoam instead of wood fiber and a few sockets less. Upgrading a cheap provider to a similar standard as a more expensive provider usually costs more than just taking the supposedly expensive one.

As for the control, you also have some disadvantages with a prefab house. What happens in the factory is not inspected by your expert. The house arrives finished on the construction site and you have to rely on the fact that all vapor barriers are okay. With a solid house that is sometimes easier. And don’t forget that with a prefab house you have to make many decisions purely based on plans, whereas with solid construction you can still change many details (e.g. sockets) during the rough construction phase.

Thank you very much – that’s exactly the information we are currently trying to gather, and also to get a feel for prices & realities etc. Also things like “what can we reasonably do ourselves”—I can paint a wall white—if we want any kind of plastering techniques, that will probably not work. I can lay a basic wooden floor or tiles, but any elaborate patterns will probably be tight. Then there are things like wanting network sockets in every (relevant) room, which are patched in the basement – of course then the question is: What does that cost more / who charges how much etc.

Insulation etc. are of course also topics: Can I judge that at this point in time? No – therefore the goal is to get into such topics and read up in order to be able to give a somewhat qualified opinion yourself and not be in a mode where “the salesman tells me a load of marketing and I have to more or less believe it” (but ideally to not have too large a knowledge asymmetry in the respective conversations).

Floor plan is indeed a very big word for that - let's call it concepts.

That's good, take your time, gain experience and meanwhile look for a plot of land. Now, it feels like there are more plots on the market.