Basement densification / demolish house

Good evening,

I own a property with a dilapidated house + a damp basement (from time to time the groundwater presses into the basement). Now I intend to demolish the house and fill/compact the basement in order to build a new house on the old footprint.
The basement is about 1 meter deep in the ground (raised basement).
Now my questions:
1.) Does the basement have to be completely removed, or can walls and floor remain in the ground?
2.) Is it advisable at all to build on the old footprint, or could the new house sink?

Thank you in advance for your answers!

Best regards

Lena

Hello Lena,

Now my questions: 1.) Does the cellar have to be completely removed, or can walls and floor remain in the ground?
2.) Is it advisable at all to build on the old foundation, or could the new house sink?

No one here can verifiably answer that for you. To provide you with a satisfactory answer to your questions, you should first consult a demolition contractor who can give you information about the existing building substance. Then a soil expert, who can give you a reliable answer regarding the soil conditions after drilling.

Kind regards

Hello Lena,
I can only agree with Bauexperte. An objective assessment by experts never hurts, and in your specific case this applies even more.

A few general notes:
Building on an existing cellar is difficult in my opinion. After all, it must be assumed that you do not want to build the same house again, and the existing load-bearing components could only be used to a limited extent. This would result in different load-bearing capacities for the new building. Furthermore, it is questionable whether and how long the load transfer via the remaining cellar walls, foundations, etc. will remain guaranteed.

I would advise completely dismantling the cellar, then having the subsoil examined by a soil expert (approx. €500) and then filling it with load-bearing material in order to construct the new building.

For further information and questions, I am happy to be available...

Regards w-bpb

Hello, I have a similar project planned, namely I have a plot with an old house (4.5 x 8.5m) and next to it a cellar (1m x 2m) with outside access. I want to demolish the entire building and rebuild in about 5 years... what do I do with the cellar? Do the walls have to be completely removed down to the base slab or is it enough to remove the walls 1m from ground level and then fill the rest? What kind of soil do you need for that? Gravel and normal fill soil?

Best regards Ronny