Building a house compared to buying a house

Thank you very much for the many responses.

Why is a renovation not an option? 1900 is a good year of construction.

We had the house appraised and it turned out that a demolition would be more economical. There is currently no heating system installed, etc. Moreover, I have to honestly admit that our craftsmanship experience is basically zero.

For me personally, a new build with the given framework conditions would definitely not be an option. Damn, wrong statement. ... a new build in such a lavish size would not be an option would be better.

Basically, we are of course also open to a smaller new build if the budget does not allow it.

20 years old should be good enough. With a difference of 200k, I would tend to the existing house here and possibly just repaint once.

The semi-detached house was only repainted last year :)

Option 1 really has to be wanted. It is already borderline now, and if children are added and the construction becomes more expensive, it will get very tight. Especially with more than one child. For me, it would also be too close to the family. You should reflect and carefully consider whether there might be potential for conflict later on because, for example, you don’t participate enough (from the parents’ perspective) in the maintenance of the shared garden or do other things differently than they expect. We also once lived directly next to the parents-in-law and are glad to have moved away from there. For example, we had agreed that one does not just show up unannounced at the door but announces oneself beforehand. That worked well for a few years, and then the mother-in-law regularly stood at the door or in the garden wanting to "just have a quick coffee." It was really difficult when my wife had no time or desire because the night with the children had been exhausting or she had other plans. That unfortunately caused a lot of trouble.

If the semi-detached house is well laid out and you like the location, I would take the plunge if I were you. Check the renovation needs more closely beforehand and look at the heating system. If it is also 20 years old, a major investment will be coming up in the next few years. However, the costs are overall more predictable than with new construction.

Good build year? Houses of that age do not have contemporary floor plans; ceiling heights that almost make tall people bump their heads; damp walls (as with the OP). You have to spend a lot of money only to live with compromises in the end.

Yes. Good build year. No years of shortages, damp basements are normal, intended, and usually unproblematic, ceiling height can just as well be normal to high. Ecological building materials, mostly thick walls and solid quality. The OP later wrote that an expert recommended demolition, so the house was probably never maintained, as indicated by the lack of heating. But the build year itself is good. In the neighborhood, such a property was renovated and was in its original condition. Now it shines like new again; I also know the owners and everything is fine. That was also a house where even I would have said it’s better to tear down, but the substance was simply still good.

Foreword: I will refrain from financing questions.

Our 1st option would be a demolition with new construction on a family plot.
The plot is approximately 420 sqm and is located on a street with a bus line. But it is right next to the family and the gardens could be connected.
The current house dates from 1900 and is half-basemented with a vaulted cellar; renovation is definitely not an option for us.
Regarding the new construction, we would have to build two full floors and a pitched roof with a 45-degree angle.
We would like about 150 sqm of living space. We are open to both solid construction and prefabricated houses.
Regarding the cellar, we definitely want to keep it and would possibly cellar it completely.
Unfortunately, we would have to plan a fire protection wall because of the distance to the other houses.

The 2nd option would be to buy a semi-detached house.
It is located in a somewhat quieter traffic area, about 300m further away from the family.
However, the plot is only 304 sqm.
The semi-detached house is 20 years old but in a very well-maintained condition, is fully basemented and has 140 sqm of living space without the cellar.

A twenty-year-old house is almost ideal. Everything is fresh enough not to require modernization, let alone renovation; any possible construction damage has long since become visible.
I don’t understand several points about the old building: fire protection wall due to what minimal distance, is it attached on one side?; two full floors really mandatory with a circle around?; I don’t understand the cellaring of the cellar at all. Building on a vaulted cellar is, to put it mildly, non-trivial and never ever suitable for a fixed price promise; this must definitely be planned by a specially experienced architect. Federal state BY, far away from – but maybe he has at least an opinion on this (?)

First of all: I will refrain from financing questions. A twenty-year-old house is almost optimal. Everything fresh enough that nothing needs modernizing, and certainly no renovation; any possible construction defects have long since become visible. I don’t understand several points about the old building: fire protection wall due to what small distance, is it attached on one side?; are two full stories really mandatory with a circle around them?; I don’t understand the cellar underpinning at all. Building on a vaulted cellar is, to say the least, not trivial and never, ever suitable for a fixed-price promise; it must be planned by an architect with relevant experience. State BY, far away from – but maybe he has at least an opinion on it (?)

The old building is located in the extended town center and the distance to the next building is less than 5m, so that, at least that’s what was said, a fire protection wall would be required. Yes, the two full stories are mandatory with a circle around them according to the development plan.

The semi-detached house was only repainted last year :)

It probably means removing memories of previous occupants after moving out and giving it a personal touch and freshness :)

We currently have no children, but they are planned.

Plural, so two, means several years of a part-time job or otherwise part-time...

From the household calculation, we could theoretically afford both.

...That then reduces the household calculation in salaries and expenses grow. In my opinion, the cost estimate starting from the basement with €35,000 is far too low. Basement at least double that, outdoor facilities (a gate is expensive, and then there’s a fence too?!) you probably only get the paving and kitchen — for a family kitchen you already pay more at IKEA. Therefore, I would make peace with the semi-detached house in your place. Personally, I also see more potential for conflict with family living too close in the long run.

We also once lived right next to the parents-in-law and are glad we moved away from there again. For example, we agreed that one does not just show up at the door without notice but announces beforehand. That worked well for a few years and then the mother-in-law regularly stood at the door or in the garden and wanted to "just have a quick coffee."

Exactly that happened with our neighbors. At some point, mother-in-law was standing more than three times a week at the door with cake. Rang the bell and then let herself in. Exhausted and just rushing into the evening, our neighbor eventually was no longer amused by her mother-in-law’s stressed and sudden coffee party attacks.

We did ask the current owners, who denied it, but we had the feeling of having heard something.

Well... we also hear the neighbors in our detached house when they're in their old phases. Not to mention car doors. Usually it comes through the windows. And yes, you can’t completely rule out hearing noises from next door through the dividing wall. But there might be other noises from outside that are possibly more disturbing.