First conversation with the developer - first numbers...

We have often painted and wallpapered and bring experience with us. We have also laid laminate ourselves. Of course, we are not building the garage ourselves; we will have it built later!

Laminate, fine by me. Painting, okay, but have you ever done it in the stairwell of a single-family house? And you do realize that before painting you have to fill and sand, which is much more work than the actual whitewashing? For amateurs, that means several weeks of work for two people..

Town & Country is okay, but rather lower standard. If you are aware of that, it's totally fine. They also build solid houses. However, you should question which features you really want and compare them with Town & Country. I would definitely plan a decent sample buffer (certainly 20k).

Just a few remarks on the costs listed:

Connection fees and costs (water, sewage, electricity, gas, sewer connection): €10,000 ---- fits
Costs for additional foundation, raised foundation: €5,000 --- You have to assess the plot yourself (if it really is flat, that might be accurate)
Removal of excavation soil: €1,000 --- (practically nothing, landfill for excavation soil costs a lot. I would plan at least a 10k buffer here)
Construction water and power connection: €1,000 --- (maybe a bit tight, but doesn't make a huge difference)
Wallpapering and flooring material: €5,000 ---- way too little, for how many sqm should the flooring be? Maybe a lot will be tiled, and Town & Country covers that?
Outdoor area material: €5,000 ----- That's nothing even for DIY. Just take a look at what gravel and the cheapest DIY store paving costs. Then you still have no beds, splash guard, planting, lawn, terrace, maybe terrace roofing, outdoor lighting, maybe a small retaining wall after all. I would calculate 20k in DIY here.
Garage 6x8 m base slab: €8,000 --- so just the base slab? How much are you budgeting for the garage (even if it comes later)
Site plan, staking out, permit fees, other fees: €3,500 --- (roughly fits)
Interest during the construction period: €2,500
Sampling buffer, kitchen: €10,000 ---- just a kitchen for 10k is already tight but definitely doable, then you better really stick to Ikea and be somewhat handy. Then there is no buffer left for sampling. Where are the other furniture? Even if you think everything is there. Bathroom furniture, coat rack? Simply the lamps cost a lot of money
Additional notary costs: €1,000 --- probably a bit tight

So everything is very tight, and I consider this unrealistic. Even if you really do not select any extras (which already requires some discipline with Town & Country), I would certainly expect 20k extra costs + garage (+ then also the buffer for selecting extras).

A floor plan with 3 children's rooms and a large bathroom in that size I want to see first.
We are building 3 children's rooms ourselves and I think nothing reasonable comes under 150-160 sqm (for me at least).

Show me a 1.5-story floor plan with 120m² where you have 3 children's rooms, a bedroom, and a large bathroom on the upper floor, and also an accessible storage space in the roof peak.

That is indeed in the initial post, but further on the "Lichthaus" from Town & Country is mentioned – and that has just under 160 m2 and 4 bedrooms with 12 to 14 m2 in the attic. Contradictory, yes.

That is stated in the initial post, but further on "Lichthaus" from Town & Country is mentioned - and that has just under 160 m2 and 4 bedrooms with 12 to 14 m2 in the attic. Contradictory, yes

Lichthaus 121 might be built, that is 120.46 m2 living space, nothing contradictory...

Lichthaus 121 is possibly going to be built, that is 120.46 m2 of living space, nothing contradictory...

We’re not going to fixate on the m2 yet, but we also don’t need a house with 170 - 180 m2, and when the kids have moved out, what do you do with so many rooms and so much space? You have to think about later, too. After all, we only build once for a lifetime. Besides, all of that also needs to be kept clean and maintained.

We have often painted and wallpapered before and bring experience with us. We have also laid laminate flooring ourselves. Of course, we won’t build the garage ourselves; we’ll have it built later!

Good, great. But you also have the outdoor facilities with EL included. And laminating or painting one room is something different than a whole house. The vacation days disappear quickly like that. A desk worker can suffer troublesome long-term effects – you have to know that. But it’s all doable.

"Lichthaus" from Town & Country is mentioned-

"My" Lichthaus has 121 sqm... do all Flairs now get called "Lichthaus" just because they have one more window or dormer?

Architect-designed houses as well as Town & Country and some solid houses or Weberhaus have their justification for existence. You just have to know that it’s not a competition to get a piece of house as cheaply as possible like the fridge xy, where you check Idealo for the best price and then get it with a few discount coupons somewhere else at a very cheap rate.

You actually get significantly less or more for the money accordingly. And/but yes: the house works. While with xy the underfloor heating, Kfw55, and controlled residential ventilation as well as the 30 x 60 tiles are already priced in, you get a basic house with some others. Some say "better a basic house than no house," others take this basic house like a modular system and upgrade considerably or a bit. That is all legitimate and understandable from the budget perspective.

Still, you should consider that many small costs add up to the point where you could have gotten a more expensive house for less. The experienced plumbing team of xy can install controlled residential ventilation blindfolded and achieve Kfw55 standard without defects, while the basic house building team has less experience in this quality and might have to make several corrections to deliver Kfw55. Also, the tiler might not be keen on large formats and charge moon prices for installation. You have to weigh and calculate all that. You don’t have to choose the cheapest house builder right away if you can afford better and naturally want something more than standard.

Lichthaus 121 might possibly be built, that is 120.46 m2 living space, nothing contradictory…

But you can’t fit 4 bedrooms in the upper floor. Note that there are sloping ceilings upstairs and that there still have to be entrances for each room. And the utility room of just under 5 sqm (shell dimension) is an absolute outrage. I wouldn’t even want that in a two-person household.