ᐅ How can the costs for a slab foundation with HQ100 be estimated?

Hello everyone,
I have a plot of land in the HQ100 area and would like to build a small house. Now I need to meet the requirements that apply to the HQ100 area. What exactly should I expect, what needs to be fulfilled, and how do you estimate the costs? The house will not have a basement but will be built on a concrete slab. Small stilts with a concrete slab are also an option.
I would really appreciate your answers!
Thank you very much and best regards

Wow. Really extensive information provided here.

The simplest answer is: for risks and side effects, consult your designer and/or structural engineer.

Since posting links is not allowed here, just try googling the topic. The most comprehensive information can actually be found with the Chamber of Commerce and Industry (IHK).

steeven01 schrieb:

Now I have to meet the requirements that apply in the HQ100 area

Legal or technical.
Legally, you can find information online from each local authority (or your federal state) – the property – new construction is prohibited in HQ100. If an exception permit is granted (which can be clarified with a building permit / planning permission inquiry), various technical conditions must be met – but these can vary depending on the federal state.
There may be regulations requiring the foundation slab to be above the HQ100 level plus an additional 50cm (20 inches) wave impact buffer. Or it may be required to pour a waterproof concrete slab only. There are really very different requirements across different regions and also depending on the exact location within the area. You might need a structural flow analysis. Or other measures, and so on.

There is no one-size-fits-all answer. But you can look up the legal requirements for your property yourself.

nordanney schrieb:

Legally or technically.
Legally, you can find information online for each municipality (or your federal state) – the plot. New construction is prohibited in the HQ100 flood zone. If an exception permit is possible (this can be clarified with a preliminary building inquiry), various technical requirements must be met – but these can vary depending on the federal state.
There may be regulations that the foundation slab must be located above the HQ100 level plus an additional 50cm (20 inches) wave impact buffer. Or it might only be required to cast a waterproof concrete slab (WU-slab). There are really very different requirements in different states and also depending on the exact location of the area. Perhaps you will need a structural hydraulic engineering report. Or other things.

You cannot give a general answer. But you can look up the legal regulations for the plot yourself.

Thank you very much – it seems really complicated! Even though the plot is right in the town center and work has already started on a flood mitigation project. Still, we currently have to build according to HQ100 standards, unfortunately! Actually, I was more interested in the height of the foundation slab, how high it needs to be built and where I can find this information, since there are no clear reference points. However, since the plot is located towards the rear, I imagine it might not involve much more effort, and I would like to build somewhat higher anyway because of possible heavy rainfall events.
Thank you very much for your reply!
Best regards