Soil report for bungalow 140 sqm, additional costs for WU concrete?

Yes, of course! I’m happy to do that! I also wanted to send you a private message, but I’m not authorized yet. :)

I also find it problematic that we have to ask questions. I don’t want to accuse anyone, but it’s at least "strange"... We did a little more unpacking and received the invoice today. It was also "overlooked" that we didn’t want the HW front door from the standard for example, and this has to be deducted. Another 1k. So as always when building: check and question everything...

We have agreed with the soil expert that he will examine the topsoil right away, then we will know what we can do with the soil. Basically, it’s about 200 m3 and a bit too much for our 700 sqm plot.

I have been interested for a while now in how this outrageous surcharge for WU? comes about. I had a 220m2 base slab, 45m3 ready-mix concrete. I believe the surcharges for WU were 1€/m3? so 45€? I paid with a large pump, I think 4.5k gross? That was 2 years ago. or am I mixing something up here?

Additional cost WU base slab with me was 1885 euros. 85 sqm, 25cm thick. Offer GU beginning 2022.

Regarding the general prices and specifications, I can unfortunately say little. However, the costs for the concrete only make up part of the total additional costs. Normal C 25/30 concrete costs around €100 / m³, in the WU version then €125 up to €150 (very roughly, I also don't know how prices are currently changing).

In addition, as written by the home building company: slab at least 25 cm + more steel, renewed structural calculation? Then increased effort with the penetrations, regarding the sealing. The whole thing already drags quite a considerable chain of consequences behind it.

I also find the €131 per m² additional costs quite high, but I was already aware that this sealing variant entails high additional costs.

We arranged with the soil expert that he will examine the topsoil immediately, then we will also know what we can do with the soil. Basically, it is about 200 m3 and a bit too much for our 700 sqm plot.

Good decision.

So, I spoke today with the contact person at the waterworks, who was on vacation before. Basically, drainage is allowed. He explained to me that the water is then collected in a container filled with sand and then directed to the rainwater system. We have to take care of the cleaning of this container ourselves. He then put me through to the wastewater contact person. He also said again: Drainage is tolerated. I have to submit an application with the connection, there is an area calculation form that is important. The latter said he would recommend that we do both: WU and drainage. This of course confuses us even more now.

We are now waiting for the change in the report and then we will also have it in black and white regarding the guarantee. Right?

So, the soil surveyor guarantees that the drainage will work. However, no one can guarantee that the drainage will function forever. Anything can happen... like a tree root growing in there and clogging the drain or something. But to reassure you, what should happen? As I already wrote, nothing can come under the house because of the strip foundations. So it's only about the outer edge. Normally, the surface is profiled so that stormwater flows away from the house. Water would really have to stand at the house and do so for a while. And if the drainage pipe were clogged, you still have a gravel trench with a slope around the pipe that leads the water away.

So unless you happen to live on a slope where streams of water run superficially right onto your house and splash onto the floor slab from above, it will work.

Cheers