Building plot with already constructed basement from 2017

Hello everyone,

we have a plot of land in sight where a basement for a single-family house was already built in 2017. After that, the construction was stopped and now only the basement exists. However, the floor slab on the basement is a bit too small for us, or it does not fully correspond to our ideas of the layout of the ground floor.

Is it generally possible to extend the floor slab now? Does anyone have experience with something like this?

An alternative would be to remove the basement again and then do everything anew. How high do you estimate the costs for that?

Hello mrmojo1

expanding the base slab is always possible. The basement can also be enlarged. It is always a question of cost.
It becomes completely uneconomical to dismantle and renew the basement.

Steven

Hello everyone,

Hello

we have a plot in sight on which a basement for a single-family house was already built in 2017.

That is great.

After that, the construction was stopped and now only the basement exists.
However, the floor slab on top of the basement is a bit too small for us, or rather does not 100% correspond to our floor plan ideas for the ground floor.

That is less than ideal. Whether something like that can be fixed can’t be judged without plans and photos.

Is it generally possible to still expand the floor slab now?

“There is no such thing as can’t.” You are talking about the floor slab and only first about the basement?

Does anyone have experience with something like this?

Your builder of choice can answer that.

An alternative would be to remove the basement again and then do everything new.
How much would you estimate the costs for that? Most expensive solution. Crystal ball? 50k - infinite.

That surely does not pay off. Unless the plot is free or it’s your dream wish.

Please give us more information. We do not know the plot and cannot read your mind.

Will you get the planning from the previous owner?

Thank you for your answers.

So far, we have only received the floor plan of the basement from the owner. We will probably get further plans over the weekend. Since the whole thing is still up in the air, I don’t want to post the floor plan here. I quickly drew a little picture to show roughly what it looks like and what we would extend.

What information about the property could be helpful? The property has a slope of 1° and the building area is large enough to enlarge the footprint. The development plan specifies an open construction method.

We first want to be able to estimate for ourselves whether such an extension would be possible in principle and, of course, what costs we might face.

Edit:
: I only just saw your answers in the quoted text now... The little picture probably won’t help after all :D I thought it was just about understanding at first... What is the ceiling of the basement called? Isn’t that the foundation slab? So ultimately it’s about what the house then stands on (in this case the ceiling of the basement).

some measurements could still help.

The property has 676 m² with a floor area ratio of 0.4. The basement is approximately 63 m² (8mx8m) and the ground floor currently has about 73 m². To the building boundary it is about 3m downwards in my picture. That means our extension would have to be approximately ~8mx3m (- ~4mx1.5m).