Liability for errors in planning

Hello everyone,

how does it behave if the architect makes a mistake in the planning (in this case in the drainage planning)? The error only became apparent later and as a result a new building permit had to be obtained and everything was delayed. That's why the price guarantee of the prefabricated house builder could not be maintained. The architect was appointed or recommended by the sales representative of the prefabricated house provider. However, there is a separate contract with this architect. In addition, a wrong soil survey was presented when signing the construction contract. This was only suitable for a slab foundation, but not for a basement, which was required. As a result, the planning of the drainage plan was further delayed. Is the price increase lawful or who must be liable for it, or does the builder have to bite the bullet here?

Thank you very much for answers!

Why doesn't one ask such a question to a specialist aka lawyer who is well-versed in these matters, instead of asking a forum, which in the end can also provide incorrect information?!

With so little information, you won't get a useful answer even from a lawyer.

In my opinion, the planner is liable for his work. What does the contract say about liability?

Why doesn't one ask such a question to a professional aka lawyer who is well-versed in these matters, instead of asking a forum, which in the end could also provide false information?!

Because one might want to hear a second opinion. That's what the forum is for.

The architect was provided or recommended by the sales representative of the prefabricated house supplier. However, there is a separate contract with this architect.

That sounds confusing ...

Furthermore, when signing the construction contract, a wrong soil report was presented. It was only suitable for a slab foundation, but not for a cellar, which was required.

... a little more than that, and especially this one from another thread ...

May I ask what went wrong with your construction and whether everything turned out well? Could we exchange views about the company Hans Erhard Massivbau?

How many houses are you building at the moment?