Contract for cellar construction - masonry

Yes, I will do that in the next conversation.
This is not a slope. - The building window is absolutely flat.

We will commission a soil survey after purchasing the property.
Depending on that, it will also be decided how the basement will be built.
The general contractor does not expect any problems but has assured that in case of load scenarios, a concrete basement (white tub) would not cost more than 6,000 EUR extra.

We would really like to have a basement because we appreciate the space.
We currently rent and only have a small storage room that is packed full to the brim with things. Bicycle trailer, tools, furniture that we might still need later, ...

I don’t find a raw construction height of 2.26m very generous. What floor construction will there be, possibly only in 10 years. Also consider this for the door height.

Yes, I thought so too. I am 1.90m tall myself. So from the bare floor slab to the raw ceiling there are only about ~33cm.
And maybe we will want to have screed and heating after all.

Never brick a basement. You will only get problems and very high costs in case of damage.

I have read that advice several times. Is it really like that?
And then: Why do the GCs still build with it?
I mean, they are the ones who have decades of experience.

I would never ever build a basement wall again ... maybe you do that if you build the shell structure yourself .. but if you don't waterproof it correctly, you will have problems that will make you wish you had spent the 6000 euros .... the bitumen with which it is coated doesn't last forever either ....

Hello MaxiFett

I have a masonry cellar made of sand-lime brick. What problems should occur there? Bitumen, perimeter insulation, and then studded foil on top. That lasts forever. I think a lot of concrete, but not for the walls.
226cm raw construction height is of course too little. Add another brick, then you are at 246.
For me, a house without a cellar is not suitable. And the possible resale can be realized with a higher purchase price.

Steven

There is news.

The basement is not necessary, but it is probably economically sensible because:
The property was part of an old landfill for household waste from the 1950s.
The household waste was burned and then spread over many areas. Among others, on the site.

Now the city says: If you want to build something there, it is not allowed on filled ground that was not originally there. Therefore, everything on which a house is to be built must be completely excavated and transported to a landfill.

A civil engineer of the general contractor has already estimated and said that before filling the hole again, compacting it, and putting a slab on it, building a basement would be just as expensive.

More details are to be provided by the soil investigation after the purchase of the property. What is necessary and makes sense and in what form.

I have a masonry basement made of sand-lime brick. What problems should arise? Bitumen, perimeter insulation, and then dimpled membrane. That lasts forever. I think a lot of concrete, but not for the walls.

Why don’t you like concrete basements?
The statement of the general contractor is: We can do it, but concrete sweats. Therefore, Styrofoam insulation does not make sense either, as it would rot away.
A masonry basement would be built from 36.5 cm aerated concrete and is therefore already practically "insulated."

Now the city says: If you want to build something there, it can't be on filled soil that wasn't originally there. Therefore, everything on which a house is to be placed must be completely excavated and transported to a landfill.

And how far? To the Earth's core or what?

Further details are supposed to come from the soil survey after the land purchase

The property was part of an old landfill for household waste from the 1950s.
The household waste was burned and then spread over many areas. Among others, on this site.

But that can backfire big time. Do you know what disposal costs on landfills are for contaminated soil? It starts with the fact that they only accept limited amounts of excavated soil, and you might have to drive extremely long distances for transport. No wonder that 90% of landfills with Z-classes are only available upon request.
I would definitely invest the 500€ for a soil survey beforehand and absolutely not check just 2 holes...

Back to the first point: I hope you're aware of how many cubic meters add up there.

10-15k EUR called for the civil engineer

No way, especially if you also have to excavate for your driveway/access/path/terrace etc.

The basement is not necessary, but it is probably economically sensible because: The property was part of an old landfill for household waste from the 1950s. The household waste was burned and then distributed over many areas. Among others, on this site.

So if I read it like this, I would say: Hands off! The potential risks are financially incalculable.

(Can you say where exactly this is? Possibly also by PM if you don’t want to say it publicly. I can hardly imagine building on a landfill.)

Best regards