Building a residential/hobby basement underground - What to consider?

I always have to think of stories like Kampusch when someone is planning something underground

Hello ypg

you might have train of thoughts. A panic room, okay, I can understand that. But something like that right away? The word paranoia comes to mind. But it is actually widespread in a nanny state.


Steven

Hello ypg

you might have thought processes.
A panic room, okay, I can understand that. But something like that right away? The word paranoia comes to mind. But it is actually widespread in a nanny state.


Steven

This is not paranoia, such things accompany me in my job.

And somewhere the split personalities are sitting and waiting for their chance.... in the meantime, a box is being built underground.... huarrrrrh [emoji12]

that sounds super interesting. I will gladly take you up on your offer and contact you via pm

I also don’t have to transport away the excavation soil. I want to partially fill the plot anyway, so it will all be used

for the rest
It is supposed to be a gym. The garage currently being used for this has to be emptied because my wife would like to park her car there in the future.
Underground for that reason, we actually have enough space and land to build it above ground, but somehow an above-ground "block" would somehow spoil the overall appearance in my opinion. You could still put it behind the garage, there is still enough space, but a barbecue area is actually planned there and then the question would again be how to build it nicely visually.

In fact, we have 4 floors of living space (including basement and attic), but all rooms are already occupied and not usable as a gym. Gym for me doesn’t mean a treadmill and 2 dumbbells, but proper strength training with heavy weights. The ceiling can’t support that.
Unfortunately, the basement only has a room height of 2.10m. That is not enough for training equipment and various executions.

So no split personality or anything like that

That floor does not carry any load.

What kind of intermediate floor is that? Every partition wall is heavier than your weight plates.

A completely ordinary concrete ceiling. I assumed it would exceed the load that a ceiling can bear. Weight plates on the rack including barbell with weight are occasionally over 400kg

However, this does not change the fact that there is no space for this in the living areas, as they are already being used differently.

I think that's a crazy idea. Neutral for floor area ratio and plot ratio since underground is probably yes, but by no means exempt from approval. Basically comparable to a double garage with earth load and therefore at least not cheaper than one; additionally, to even be eligible for occupancy approval: ventilation and exhaust like in an underground garage, escape routes, etc. And almost certainly the first such case in the entire district office area. Associations in the local rumor mill in the direction of Kampusch or Fritzl included.