Feasibility assessment: Multi-family house design by the architect?

Dear community,

we are considering whether it would be possible to build a multi-family house (2 residential units) on a plot of land. Due to the characteristics of the plot (quite narrow but very deep, boundary development rather unlikely), it is not entirely clear to us as laypeople whether and especially how something like this could be realized. What is the best approach here? For example, could we have designs created by an architect to assess feasibility? What costs should we expect? Are there other ways we could estimate feasibility?

Thank you very much for your tips!

In the first step, I would check whether there is a legally binding development plan for the respective plot. Floor area ratio and plot ratio specifications are defined here, and thus also the maximum possible living area. Often, there are also restrictions on the number of possible residential units.

If there is no development plan, the building must fit into the surroundings. Therefore, the directly adjacent buildings often give a good indication of the area of the plot and the type (one-/two-story - flat roof/gable roof) in which development could be feasible.

Has all this already been checked? This is not clear from the initial post.

In the next step, an architect would be a suitable contact person to develop a sensible design of the house and the residential units.

Is a house with 2 residential units already considered a multi-family house? (I don’t think so, which should make things rather easier.)

Does a house with 2 residential units already count as a multi-family house? (I don't think so, which should actually make things easier.)

No. That is a two-family house (two...), not a multi-family house (more...). The latter can only be built in designated areas. Even the parking space alone plays a challenging role.

we are considering whether it would be possible to build a multi-family house (2 residential units) on a plot of land.

Unfortunately, we cannot think along with you – for that, you would at least have to enlighten us with a cadastral plan and an aerial photograph. A deep plot does not necessarily result in a deep building window, and boundary construction with living spaces: usually no.

Hello dear forum,

First of all, thank you for your active participation. I think I may have expressed myself somewhat unclearly. To begin with, the development plan is available and there are also some two-/three-family houses in the neighborhood.
My question: We are looking for sketches/designs from architects to assess what would be feasible. Can you simply have something (roughly) designed here? What would something like that cost?

Thanks and best regards