Demolition and new construction, basement, hillside location

Sparclou? There was no talk of a Sparclou. In the area where we would like to live/build, almost everything is on a slope, so we can't avoid the generally higher costs of construction anyway. If you were to buy a comparable plot of land empty, it would still be more expensive than this one including the demolition of the existing house. Especially since there is already a house with a basement there, it is at least clear that the soil conditions allow this. The slope is probably about 15%. Accordingly, it probably makes little to no sense to build on BP, especially since there is currently a basement excavation. The necessary earthworks would probably not be less extensive than building a new basement. And we want a part usable basement anyway. It is of course clear that you cannot completely avoid earthworks. However, it is relatively difficult to identify potential costs given the existing conditions. It basically only says that with sloping land a basement is hardly more expensive than a BP and that the earthworks represent a significant proportion of the costs. That is why my question is whether it would be more sensible to add a prefabricated basement as a usable basement on which you then build a house, or to build the basement so that you can partially use it as living space downhill and build one less floor for that. What is roughly the price difference between a living basement and a usable basement? What is the ballpark figure for earthworks, etc.?

Utility basement for which use + living area is more expensive than residential basement + reduced living area above ground both have the same living area

If you were to buy a comparable plot vacant, it would still be more expensive than this including demolition of the existing house.

This statement makes little sense.
That may be true, but it is generally very unlikely. I don’t know how many times I have read something like this here. Why should the seller want less? Or to come back to your specific example: Why should other interested parties offer less precisely here? You can’t even know what they are offering. The starting price says nothing. They also know what it costs in the surrounding area. Accordingly, the price will settle.
Plot costs from the surrounding area minus demolition costs at best.

However, it is relatively difficult to identify potential costs under the existing conditions. It essentially only states that with a hillside location a basement is hardly more expensive than a BP and that earthworks constitute a non-negligible share of the costs.

Yes, and here additional costs arise from the disposal of the old basement. Depending on year of construction + condition, possibly even hazardous waste?

That’s why my question is whether it would be more sensible to add a prefabricated basement as a utility basement on top of which a house is then built or to build the basement so that it can be partially used as living space downhill and thus build one less floor. What is roughly the price difference between a living basement and a utility basement? What is the ballpark figure for earthworks, etc.?

You can’t say that in general. It depends on so many factors. Location, condition, size to name just a fraction. Below is a post as an example. I would just use the search and click through. There are several threads here with similar houses. A normal basement on a standard 0815 plot should be doable for about 70k. But as mentioned above, that reference point will not tell you much.
My layman’s opinion, which I have formed here over time, is that due to the hillside location a living basement becomes very, very much more affordable than without a hillside location. For this “small” surcharge it is therefore worthwhile for many. If the budget does not allow it, then it simply won’t work.
But if you can save an entire floor by having a living basement, it is estimated to be cheaper to build with a living basement. But don’t forget that by doing so you lose corresponding sqm. I mean, it is quite a difference whether I build 2 residential floors + basement or just 2 residential floors.

Here is a post from a user. Just to have a reference point.

Since we are currently also building a living basement which is not entirely dissimilar to what you intend (approx. 155 sqm, 28 cm waterproof concrete exterior walls, 14 cm insulation outside as well as under BP, except in the garage area approx. 25 sqm, since outside the thermal envelope), here is what we have to invest:

Shell construction (prefabricated elements, incl. interior walls and 3 basement windows): 102k Euro
Sanitary drinking-/wastewater: 7k Euro
Underfloor heating (everything except garage and utility room): 9k Euro
Controlled residential ventilation (pipes only, system itself separate): 7.6k Euro

We are already at about 125k Euro, and the costs for screed, flooring, electrical installation, plastering/painting walls, possibly suspended ceiling, staircase basement-ground floor as well as additional costs for excavation and possibly disposal compared to BP are not yet included.

Therefore, in my opinion, the 150k Euro are quite realistic, 200k Euro on the other hand probably a bit too much – but this certainly depends on the region (we are in a rather inexpensive area).

Prices for the basement were roughly given to you - you can't say more with the information available. The price depends on the area, the soil condition, and the overall slope. So nobody can tell you more precisely. But if you calculate with €2,000 - €2,500/sqm, you should be quite close.

However, I would pay a little more attention to the "demolition" area. You have to demolish an entire house, right? You are aware of that? How have you planned that? Gutting it yourself - does that make it cheaper? Do you know what was installed? There was a time when asbestos facade panels were very fashionable and common. If you have to dispose of that today, you won’t have fun, it will be expensive.

You can estimate the basement, but what surprises the demolition may hold would make me feel much more uneasy...

This statement makes little sense.
That may be true, but is usually very unlikely. I don’t know how many times I have read something like this here. Why should the seller want less? Or to come back to your specific example, why should other interested parties offer less here? You simply can’t know what they offer. The starting price means nothing. They also know what it costs in the area. Accordingly, the price will turn out.
Land costs from the area minus demolition costs at best.

I expressed myself a bit unclearly there. Of course, it could be that such a high bid would be made, but then we would drop out. Our limit would be if, in the end, after demolition and clearing, we would arrive at the land value. Otherwise, we would let it go. This is not the first auction; last time it did not sell, the creditor’s claim is significantly below the market value, so it wouldn’t be excluded to get it cheaper. Someone still lives there and, as said, it would have to be demolished and cleared out, which doesn’t bother us much since we wouldn’t want to start building immediately anyway, but for others it is probably rather uninteresting because of that.

Yes, and here come additional costs due to disposal of the old basement. Depending on the year of construction + condition possibly even hazardous waste?

Yes, we are still trying to find that out. The expert report does not reveal much in this regard. We will get access to the files at the court again to see if there is any further information.
Also : estimated demolition costs were calculated in the expert report. But I don’t know to what extent materials were examined more closely. Of course, we would not do that ourselves, but have it demolished. But naturally, more costs would arise if, for example, it involves asbestos. The house is from the 50s, so there is a risk, but also a chance, that asbestos was not used.

You cannot generally say that. It depends on so many factors. Location, condition, size, just to name a fraction. Below is a post as an example. I would just use the search and click through. There are some threads here with similar houses. A normal basement on an ordinary plot should be feasible for about 70k. But as mentioned above, that reference point doesn’t help you much.
My amateur opinion, which I have formed here over time, is that due to the hillside location, a livable basement becomes much much more affordable than without a hillside. For this “small” additional cost it is therefore worthwhile for many. If the budget does not allow it, then it just doesn’t work.
But if you can save a complete floor through the livable basement, it is estimated to be cheaper to build with a livable basement. But don’t forget that you will lose corresponding sqm in the process. I mean, it is quite a difference whether I build 2 residential floors + basement or just 2 residential floors.

That already helps, thank you very much!
Basically, it is about the following:
So, if we assume roughly 160-170 sqm of desired living space, I could (I’ll simplify the calculation now) build an 80-85 sqm basement and put 2 corresponding full floors on top.
Or I build a 100-110 sqm basement, of which I use 60 sqm as living space and 40-50 as utility basement, and build only one floor with 100-110 sqm on top. Living space remains the same. And we actually don’t need an 80 sqm basement. It would be for building services, laundry room and tool cellar plus some storage space.
Altogether about 200 instead of 240 sqm and therefore cheaper – or does the saving cancel out again because of larger excavation and the partial living basement being more expensive compared to a utility basement?!
We basically have a relatively large budget scope. But of course, before potentially bidding on something, we want to have a rough idea, because obviously the effort to make the plot ready for building would not be insignificant.

That already helps, thank you very much! Basically, it’s about the following: so if we assume a desired living area of 160-170 sqm, I could (I’ll simplify the calculation now) build an 80-85 sqm basement and put 2 corresponding full stories on top of it. Or I build a 100-110 sqm basement from which I use 60 sqm as living space and 40-50 as utility basement and just build one story with 100-110 on top. Living area remains the same. And we actually don’t need an 80 sqm basement. That would be for building services, laundry room, and tool basement plus some storage space. So altogether 200 instead of 240 sqm and thus cheaper – or does the saving cancel out again because larger excavation and partly living basement compared to utility basement would be more expensive?! We basically have a relatively large budget leeway. But of course, before we potentially bid on something, we want to have an approximate feeling because, naturally, the effort to make the plot suitable for construction would not be negligible.

Tell me what “a relatively large budget leeway” specifically means. Have you looked at the development plan? You can’t build just anything anywhere. Option 1 can quickly disappear from the screen because of that. But option 2 is still the more sensible method here. Depending on the size of the plot and the amount of excavation, you can also simply spread it on the plot and save on disposal costs. Those are also a major price driver in earthworks.