Renovate or demolish and rebuild?

That is also my opinion,

however, just because BUs enter this value on their homepage is a myth.

I actually also find it a bit too good to be true, that's why I took x2 as a basis.

Today after half a year I received the cost estimate and I was nearly shocked.
Estimated just under €900,000, but including the planning of the outdoor area as well as the terrace.

Simply writing €900k and that you’re shocked doesn't help us at all. If the house has 450 sqm of living space, the price including the extension is even rather cheap. If it’s 120 sqm, then it’s beyond good and evil.

Pictures, location, etc. also help extremely.

Apart from that, a new build costs around €2,500 per sqm of living space (minimum standard). So you will already have to reckon with around €300k for a small 120 sqm house.

Turnkey or shell houses are apparently available from around €150,000.

These prices for a turnkey house (plus foundation slab) are worth just as much as the €900k for a renovation.

Simply saying T€ 900 and that it shocks you doesn't help us at all. If the house has 450 sqm of living space, the price including the extension is actually rather cheap. If it is 120 sqm, then it's beyond good and evil.

Pictures, location etc. also help a lot.

Apart from that, a new build costs about T€ 2.5 per sqm of living space (minimum standard). So for a small 120 sqm house, you will have to reckon with about T€ 300.

These prices for a turnkey house (plus the foundation slab) are worth just as much as the T€ 900 for a renovation.

Thanks for this "friendly" answer...
I did write that the house currently has 90 sqm of living space. In the expanded state it would be approximately 200 sqm.

Thanks for this "friendly" reply...

You're welcome. But you also don't provide any usable information ;) . I read that 90 sqm are habitable. But somehow not how the total area looks, how big the extension is, etc.

Detailed information helps for concrete answers ==> €900k as a cost estimate for a 210 sqm house with complete core renovation (maybe the ceiling heights will also be adjusted, but we don't know that either), is quite a gulp from the bottle. With high-quality execution, however, it is indeed within the range of what can be calculated. Especially since the outdoor facilities are also included (which, by the way, make up which proportion? Areas and architect's planning? Unfortunately, I haven't read that either. But landscaping a 1,000 sqm plot including a terrace quickly becomes six digits as well.

Do you now understand why I said that your question cannot expect an answer without information? No offense meant. But if you say that a car salesman told you the car costs €100k and the price seems unimaginable to you, a third party can say that the offer is a) overpriced for a Golf or b) too cheap for a Ferrari...

I am now dealing again with prefabricated houses and the demolition of the existing building. Expansion or turnkey houses are apparently available from around €150,000, although that is probably the absolute basic construction. But even if you include a buffer (x2) and I estimate the foundation slab + demolition at €100,000, I am still much better off with a new build? Of course, I then have to forego subsidies, but that would probably be negligible in this case.

Forget these prices immediately. Even for catalog prices, they are far too low. Realistic prices are, depending on the area, €2500-3000/sqm plus additional construction costs. That should still be considerably cheaper than a renovation for €900k, but it is a different magnitude than you thought. (You are probably so wrong because you mention expansion house and turnkey in the same breath. An expansion house is, simply put, a shell construction. Turnkey is not always used consistently; floors and painting are sometimes included and sometimes not.) Basically, with €900k and a renovation that essentially rebuilds the entire house, I would also tend to opt for demolition.

Please also answer the questions already asked by others. And how much of the €900,000 is allocated to the exterior facilities? With 2000m2 of land, that can be quite a lot. With the given information, no one can give you any advice here.

Year of construction 1800 I personally find absolutely charming, but of course I don't know the house. Dilapidated roof, no heating, etc. sound more like neglected.