Buying a house in need of renovation - What is the best approach?

Thank you for the detailed answer. Here are a few more notes from me:

Even too expensive for Mannheim.

Although, judging by the photos, I would say at least the roof is not too old (and thus insulated?). The rest looks like how my house (three years younger) also looked...
The extensions really "ruin" the house. Looks like Frankenstein tried his hand as a builder (conservatory and whatever is supposed to be above it).

==> Complete renovation except the roof is due

What would be a "good to ok" price for you and how could I argue this in potential negotiations? According to the realtor’s exposé, the roof is not new, i.e. it is original. The extensions are really ugly, I agree with you. Here are some more pictures of the attic:

Time pressure from the seller or actual time pressure because demand is so high?

More because the demand, especially in this district, is very high. However, the trend is that we have perceived a price drop and increasing supply over the last months/years. The district is also characterized by a (very) old generation, so a change of ownership is currently taking place.

The question of course is also how you want to use the house. Judging by the photos, I would say it is a classic two-family house.

We would want to use the house as a single-family home. On the ground floor, a large living and dining area, where one (presumably) load-bearing wall would have to be removed, so that this "corridor" more or less disappears. Then a guest bathroom, wardrobe and a work-guest room. On the upper floor, more or less unchanged from the floor plan.

We wanted to have a new-build standard in the final finish. I used to be an electrician in my previous life and could certainly do some things myself (under guidance). But it is not that I could carry out every trade with 100% own effort (alone because of time).

Can you say something about the attic? I have read several times now that these are converted in Germany without a building permit. How can I recognize this exactly? The stairs to the attic look to me rather like this might be the case here as well.

My conclusion: This is a project with a volume of (well) > 1 million €. Ask yourselves whether it is worth it. Whether you can pay this with a good conscience. And whether there aren’t also other houses in this price category (or plots + new build).

My opinion: I would not take on the property. That is too expensive for me including the renovation. I’d rather buy something smaller and newer:
Modern single-family house in Mannheim-Blumenau - photovoltaic/heat pump and spacious plot for 639k
And similar objects like that can be found in Mannheim. But with smaller areas. If you have three children, the selection becomes smaller.
For example, new build semi-detached house with upscale fittings commission-free directly from the owner - 196sqm living area for 885k (house is currently under construction)

Thank you for your overall assessment. This is very helpful for us when someone evaluates the listing with neutral lenses. We will visit the house over the weekend and then I will get back to you with further details.

What would be a "good to okay" price for you and how could I argue this in possible negotiations?

Land value + a small extra charge for the basement (if dry and usable), garages, and outdoor facilities. Argument: Core renovation or demolition necessary because EVERYTHING is old. The house would not be worth more than 300k to me. After renovation, you might end up just under one million. This would make the house fit into the general price structure once finished.

According to the broker’s exposé, the roof is not new, meaning it is original.

But it doesn’t look like that. I would ask about this. A 60-year-old roof usually looks significantly worse/older.

More because the demand, especially in this district, is very high. However, the tendency has been that we are observing a price drop and increasing supply in recent months/years. The district is also characterized by a (very) old generation, so a transition is currently taking place.

The demand is not that high for exactly this property, which has been online for a month and is not yet reserved ;-) EVERYONE has to ask themselves whether they want to spend more than a million.

We would like to use the house as a single-family home. On the ground floor a large living and dining area, where (probably) a load-bearing wall would have to be removed so that this "hallway" more or less disappears. Then a guest bathroom, wardrobe, and a work-guest room. Upstairs more or less unchanged from the floor plan. We wanted a new-build standard in the final construction.

Then stay away from the house. That will be too expensive (at least economically, whether emotionally, you have to decide).

Can you say something about the attic? I have read multiple times that these are converted in Germany without building permits. How can I tell exactly? The staircase to the attic looks to me as if that could also be the case here.

This is a completely normal two-family house (which I personally would then not use with a stairwell like in a 60s rental building). It was built as it stands now. You have to ask about the extensions/dormers. It is "normal" to convert an attic if, for example, it is a two-story building and you convert the loft. Or in your case, if the loft is a bit higher, and you then insert the space-saving staircase from the upper floor to set up a studio (for whatever reason) in the loft. You recognize illegal construction by the absence of a building permit. The conversion is initially not illegal, by the way. You can also convert/renovate an attic luxuriously. You are just not allowed to use it as living space.

I have read several times now that these have been converted in Germany without a building permit. How can I recognize this exactly?

Here are some more pictures of the attic:

The back room looks usable but not finished. Regardless, just don't live there, only use it as storage space.

We would like to use the house as a single-family home. On the ground floor a large living and dining area,

You should make sure that the staircase is integrated into the living area, because currently it lies outside the living rooms and separates two floors rather than connecting them.

We wanted to have a new build standard in the final development.

Ooh, yes.. that will be expensive. And I think it will not be worthwhile.

The back room looks usable but not developed. Anyway, just don't live in it, use it only as storage space.

Sorry, I didn't see the pictures properly on my phone. You are talking about the attic - then just assume that there is no building permit/usage permit for it. But it doesn't matter. This is a bonus that is not included in the price (and not in the living area) either.

Thanks again for the quick and competent answers. One general question: I often read about asbestos and that its disposal is expensive (and also unhealthy if handled improperly). How can I (or a professional) recognize whether asbestos was used in the house at all? Of course, if panels were used on the roof or similar, this is immediately obvious. But what if it was used, for example, in tile adhesive or behind radiators, which are not easily visible or accessible for inspection?

One general question: I often read a lot about asbestos and that it is expensive to dispose of (and also unhealthy if handled incorrectly).

Yes, asbestos can (and most likely will) be present in such a house. Disposal expensive? Simply "dropping it off" at the recycling center is (at least in the Niederrhein/Ruhrgebiet/Düsseldorf region) not much more expensive than bulky waste. The professional becomes expensive if you have building materials removed and disposed of externally. For example, the Eternit panels of the facade (if there are any) can also be removed well and safely by yourself.

How do I (or the professional) even recognize if asbestos was installed in the house? Of course, if panels were used on the roof or something like that, it is directly visible. But what if it was used, for example, in tile adhesive or behind heaters that are not properly visible/checkable?

Recognize directly? Almost not at all. Even panels on the roof may not be immediately recognizable. For everything, you need an analysis. The professional therefore opens components, takes samples, and has them analyzed.
Spoiler: You can also do that yourself and send in the samples.
General problem: The whole procedure only starts after the purchase.