Granny flat / Semi-detached house advantages

So I would simply boldly claim that you can rent out an apartment in a new building with good energy efficiency in a good central location in nice medium-sized towns quite well (even at 14,15 € per m2). And yes, I know that you can also rent out a two-family house in a good location quite well. But it is undisputed that a private garden area has been highly sought after, especially since Corona. Why not just plant a hedge behind your garden and leave a strip about 6 m wide behind it for the tenant. You get privacy and less work, and the tenant is happy. Or you can make a floor plan in an L-shape so that a part of the house can be very well separated. But if the property is in a good location, I wouldn't worry about renting it out. I'm always amazed at the prices called for apartments in new buildings in the attic with many sloping ceilings and even as maisonette. But even here, they go quickly. So downtown is probably no problem to rent out (even with apartments that seem difficult at first glance).

But if the property is in a good location, I wouldn’t worry about renting it out. I’m always amazed at the prices asked for apartments in new buildings in the attic with lots of sloping ceilings and even as maisonettes. But even there, they are gone quickly. So city center is probably no problem to rent out (even with apartments that seem difficult at first glance).

You can rent out everything (in a reasonably good location). But to get both a good tenant and a good price, the apartment must fit the requirements of the desired "good" tenant. To exaggerate a bit, if my "preferred tenant" is the millionaire single, I have to rent out a loft penthouse and not a detached row house in a new development.

Or a real example, all in one building, very good location, high-quality construction:
4 rooms, 95m2, with 200m2 garden --> target group small family --> rented for 14.20/m2
2 rooms, 65m2, balcony --> target group well-off single --> rented for 13.85/m2
4 rooms, 125m2, 2 small balconies --> target group? --> not rented, currently offered for 12.00/m2

To apply this to the OP, for the desired tenant group (older couple, no children) I see it as difficult to meet the wishes of the target group. Perhaps most easily by building a house with 2 staggered maisonette apartments.
Apartment 1: ground floor + half upper floor, garden
Apartment 2: half upper floor + attic, roof terrace
But who wants tenants from above constantly looking into the garden and onto the terrace.

Thank you very much for the insights into your hobby.

4 rooms, 125m2, 2 small balconies --> target group? --> not rented out, currently on offer for 12.00/m2

I would see a shared flat in there - assuming a somewhat fair division.
Is the place a university town?

Thank you very much for the insights into your hobby.
I would see a shared flat there – assuming a reasonably fair layout.
Is the location a university town?

Only the one apartment (95m2) is rented out by me, and in this case it is actually not a "hobby" but my own investment. But one also knows some other landlords from the new condominium owners' association.
The term "hobby" comes from the fact that I have been intensively dealing with rentals and tenancy law over the last 2 years and now like to use this knowledge within the closer family environment as well ;-) .

Yes, it is a university town. The layout of the large apartment is difficult for a shared flat, 2 very small rooms, 1 attractive, large bedroom with adjacent dressing room and a very large open-plan room. The apartment was designed for personal use in old age. However, the target group "very wealthy elderly" mostly own property themselves and are not necessarily keen to have to move again in old age in case of a potential owner-occupier termination.

Hmm, that is of course an unfavorable layout. Maybe the two small rooms can be combined? My condominium was, for example, created by merging two small 1.5-room apartments. And that’s how I was found as a buyer. Before that, the sales process had already been going on for over a year, which is quite long for Berlin before Corona.

The risk of renting must not be underestimated. In most cases, it simply does not pay off with only one apartment.

As a landlord, you are basically completely without rights. That’s just how it is. Now Kevin Kühnert suggests that tenants who can no longer pay their rent should not be evicted. Others want eviction protection for tenants who can no longer manage the additional costs and advance payments. Still others, or the same people, want to abolish the allocation of property tax to the rent and/or impose health and pension insurance contributions on rental income.

If the tenant simply stops paying or cannot pay anymore, it is already unpleasant and expensive today. It takes at least 6 to 12 months and can cost five figures to get rid of the tenant. It is not uncommon for the apartments to be wrecked afterwards.

After me, the flood. And nobody is protected against tenants like that. I rent out several apartments. But where I rent, I wouldn’t want to live. And building a house just to then have to deal with tenants also doesn’t make sense.