Initial ideas for building a small house on a backlot

First of all, thank you for your answers.

Have you read a few posts and threads? As far as I know, there are currently threads here that answer many of the questions.

I have, but I must honestly say, I sometimes don’t understand the forum structure.

Some things also make little sense to me:
Floor area ratio 0.3 - so I may build a maximum of 150m2
But
Plot ratio 1 - so the building may only have a total of 500m2?
That somehow seems contradictory.

Isn’t the front property developed?
Maybe you could simply post the site plan, GoogleMaps photo, and development plan?!

As far as I know, yes. Since we haven’t purchased the property yet but rather want to know generally if it’s worthwhile (prefabricated house providers advertise with 100,000-150,000 per house without costs such as foundation/connection).

Why prefabricated house builders?

According to the internet, fast and cheap. We live in a very expensive apartment, so we cannot afford double burdens for long.
My husband would prefer a "small" 3-room tiny house.

Some things also make little sense to me:
Floor area ratio 0.3 - so I am allowed to build a maximum of 150m2
But
Plot ratio 1 - so the building is only allowed to have a total of 500m2?
That is somehow contradictory.

That is why the advice yesterday was for you to post the development plan here, because you might be interpreting it incorrectly.

It is about the shared property:


8m to the street, then 17m buildable area, then 12m and then 15m. The area behind has no marking and I also do not know how wide the parcel is.

for better visualization:

I just wondered, could one also, in consultation with the owner of the house next door, develop from there? Or does one have to go from the street?

That is somehow contradictory.

You have now clarified that through the setting of the zoning excerpts: You are allowed to build I full story and floor area ratio 0.3 = 150 sqm floor area.

According to the internet quickly and cheaply. We live in a very expensive apartment, so we cannot afford double burden for long. My husband would prefer a "small" 3-room tiny house

A "prefabricated" house is neither faster nor cheaper (or even more price-secure). You seriously want to invest 190k land price plus ancillary costs just to rebuild your apartment there and freeze its cold rent? – that sounds very much like "completely clueless" and is a fool’s errand par excellence.

I just thought, could one also connect via the owner of the house next door, from there? Or does one have to go from the street?

Your property is access-wise connected via the easement corridor of the front neighbor. This must, if the property is to have a chance for a building permit, also include rights for lines. For utilities connection, the suppliers have their own ideas, which can be found out at their builders’ advisory offices (energy provider, water, sewage, possibly gas) and "building districts" (Telekom) and vary greatly locally. Telekom still does connections to network terminations in neighboring houses, but at the municipal utilities connecting to existing lines is out of fashion; they usually require separate lines to each house.

First of all, thank you for answering my questions. That means you would need 27-30m of cables for the development. So at least 30,000€.

you are allowed I full floor and floor area ratio 0.3

And what exactly does that mean? Only bungalows or multi-story max. 500m2

You seriously want to invest 190k land price plus additional costs just to rebuild your apartment there and freeze its cold rent?

No, there are several reasons why we want to move out of our apartment. Cold rent for us is currently between 1500-2000€ for 60-80m2, we pay about 1800€ warm for our apartment (2.5 rooms) right now. Since we will move out anyway, the calculation is simple. Before I pay a landlord 2000€ monthly, I’d rather use that 2000€ to pay off a loan. However, existing properties are currently ridiculously priced and way too big for our needs. With a purchase of an existing house for 400,000€, an additional energy-efficient renovation of 100,000€ would have to be factored in. In that case, we might as well build directly. Whatever that has to do with a knapsack and a foolish prank.