Sell the property completely or partial sale with investment?

Since you need meters for water and heating, just contact the ones mentioned above.

How many residential units are we actually talking about?

Since you need meters for water and heating, just contact the ones mentioned above.

How many residential units are we actually talking about?

Sorry if the wrong impression was given. We are considering whether to plan apartments. Or in other words, we are just including them in the plan - whether we actually implement it is another matter. Theoretically, it would be 4 floors with 8 apartments each.

Currently, it looks more like the spaces will be rented out as workshops to commercial tenants. In that case, there would probably be 4 units per floor. But that might also depend on the potential tenant.

The demand for apartments is probably fairly "secure." However, you have a lot more trouble with the people and the investments are simply insane. The demand for commercial space is rather uncertain. But the investments are nowhere near as high.

At the moment, it rather looks like the spaces will be rented out as workshops to commercial tenants. There would probably be 4 units per floor. But that may also depend on the potential tenant.

Small businesses or workshops on multiple floors? Every bank will be happy about that... You lack a clear usage concept.
There are also no long-term rental contracts and frequent changes with the associated costs. The rental effort is very high; nothing works without an agent. Demand from what kind of users (?) – the lawyer certainly will not rent next to a workshop use?

The demand for apartments is probably relatively "secure". For that, you have a lot more trouble with the people and the investments are simply insane. The demand for commercial property is rather uncertain. But the investments are nowhere near as high.

I agree with you about the demand. However, not about the costs.
You will not see a drastic difference between commercial and residential (if that were the case, the commercial equipment would have to be so poor that you don’t get any tenants). Fire protection plays a bigger role in commercial properties, and building services are also a major issue (IT, air-conditioning/ventilation, tenant improvements).

If I had the choice with the property, as we have been following it for a while, I would personally quickly distance myself from commercial use. I see the stress with such properties too often.

Yes, long distances would be expected. The building alone is 40m long and has 4 floors...

I think what’s standing in your way with the images in your head is that you know the property and are familiar with it. A professional real estate developer approaches this unemotionally and comes up with unexpected solutions.

For commercial use, one could save quite a bit on equipment that a residential tenant would expect nowadays. It starts with underfloor heating. Plumbing would be less and simpler or there are already rooms that could possibly be reused. I'm not sure about the energy saving ordinance – it wouldn't be a change of use and would have existing rights? Workrooms are expectedly larger. There would accordingly be fewer doors and walls, sockets, switches, paint – whatever a wall typically needs. Fire protection probably doesn't differ much – there are likely wall suppliers who offer these as "pre-finished fire walls." So I think there is a noticeable difference. And yes, the rooms wouldn't be suitable for Edeka and Co. They said 15 years ago that they didn't want to move in there. It would be more for internet retailers or maybe a carpenter or artist or who knows what.

I see the stress with such properties too often for that.

We have already rented out commercial spaces in the area and manage very well with that. On the contrary, we are rather afraid of apartment tenants.