1) Weberhaus CityLife 600, 197 m² living space, hipped roof, price 263,000 euros (construction stage unknown, without basement, price found on the internet)
Really? Can you send me the link? The price is phenomenal, I always considered Weberhaus to be an extremely overpriced provider but that is really something.
To the actual topic: First of all, you should clearly formulate your personal wishes and then also enforce them. You want the study, for example, to be as secluded as possible. Our wish was: a work corner in the living area or at most a study on the ground floor with a line of sight to the living room with the door open. So as close to family life as possible. You want it more secluded, so for example upstairs (because the actual life takes place on the ground floor or on the ground floor but tucked away in a corner or in the basement). You have to consider if upstairs there are 3 children's rooms and 1 bedroom and probably 2 bathrooms and a dressing room, then the ground floor has to be correspondingly large. Either a huge living/dining room or the study on the ground floor (door closed = you have your peace, hopefully - that would be something to consider in your situation).
Considering your budget and the quite reasonable land prices, I would never save on the land price in your situation. Land/house = 50/50 is not unusual nowadays and what you get for 90k in Baden-Württemberg is actually beyond my understanding. Pay attention to proximity to the next larger city, S-Bahn connection to the nearest major city, schools, grammar schools, and local mobility options for you and the children by bike as well as, of course, peace, i.e., appropriate distance from highways, for example.
The world of prefab house providers is a big one and by the way, I would not forget the solid house providers, whether the construction time is 4 months or 6 months – you will probably live in the house for 40-70 years – construction time really cannot be the deciding factor.
A meaningful comparison can only be made if you define YOUR standards trade by trade. We have done that or are still doing it. It’s not that hard. Get building and service descriptions by the dozen and compare. Over time you get a feeling for even rather unimportant trades. Do you want red or anthracite-colored roof tiles? Concrete or clay? Engobed? Glazed? Which company? Window color? Foiled? Inside and outside?
Don’t let anyone talk you into an air-to-air heat pump – that only works in passive houses.
If prefab house, then with controlled residential ventilation. Anyone can tell me what they want, but aerated concrete, sand-lime brick, and brick regulate humidity to a certain degree – we found this out after countless model house visits. A wooden prefab house only works with controlled residential ventilation, but never with air heating except if it is an optimal passive house (including planning solar orientation, certainly no basement, KFW40 insulation).
Kern-Haus, which you mentioned, is basically a solid house provider. Concrete with insulation. It’s often built here where we live, certainly not bad.
I have very good experiences with Weberhaus in my circle of acquaintances.
Kampa we are currently also in talks with, very serious (first thing they gave us was the building and service description before we even talked about floor plans, etc.) and funnily enough another prefab house provider mentioned Kampa praise-worthy in casual talks. Also, the KFW40-Plus energy house concept and the entire planning including phase shift etc. is very well thought out.
Helma certainly offers solid mass construction and energy concepts if you want those too.
These are now my positive examples. I don’t want to start on the negative list now, but if you meet such salespeople who want to sell, do not hand over building and service descriptions, tell you that you can cancel the purchase at any time but please sign first or want you to sign for a type house X and in the end you could still make changes (for a good five-figure sum – they don’t tell you that). Serious companies look at your land or at least the height plan, point out multiple times the additional foundation costs especially when building with a basement or even do the soil survey (of course at your expense) before contract conclusion, plan your house based on your land (and if it does end up being a type house, well then it fits there – if someone wants to sell you something without knowledge of the land, then something is seriously wrong). If a provider’s main argument is that they have already set up the same junk thousands of times, run away.
And as I said, don’t forget solid construction. No matter how great we find the overall concepts of the providers mentioned above, a solid house also has its advantages. For example the bricks that have a phase shift of well over 24 hours and therefore keep cold inside for days while it was 30-38 degrees outside like in recent days. Where we are, solid houses cost less due to local labor costs than comparable prefab houses from quality providers. But since prefab house providers have nationwide prices, it may be the other way around for you in Baden-Württemberg and prefab houses may be cheaper than locally built masonry houses.