ᐅ Outsourcing the Foundation Slab – Sensible or Risky?

Dear forum,

We are about to make some decisions regarding our planned prefabricated house project with the company Bien-Zenker.

The local Bien-Zenker provider suggests having the foundation slab constructed by a local contractor, as this is cheaper than having Bien-Zenker do it directly. What are your thoughts on this, especially considering that it involves two separate trades and Bien-Zenker would only be responsible starting from the foundation slab?

Thank you very much!

Jay_Kay schrieb:

The local Bien-Zenker supplier recommends having the foundation slab built by a local contractor, since this is cheaper than having Bien-Zenker do it directly. What do you think about this, also considering that this means two separate contracts and Bien-Zenker would only be responsible starting from the foundation slab?

Don’t let yourself be persuaded to split the contract between the “house construction contract” and the “foundation slab.” The top edge of the basement ceiling or foundation slab is an extremely critical joint. You shouldn’t give the supplier any leverage to pass responsibility onto a third party. The trouble—especially the delays caused by disputes over whose fault a poor fit is—is not worth chasing savings here. The sales representative achieves two goals at once: they shift the house manufacturer out of liability for the work of their subcontractor and receive a higher commission from the foundation slab provider than if the contract remains correctly combined as it should be.

---

https://www.instagram.com/11antgmxde/
https://www.linkedin.com/company/bauen-jetzt/

From a warranty perspective, as @11ant points out, it is a disadvantage. On the other hand, many houses are built this way – ours included. The foundation work and slab were done by BKB Koch, and the house was built by SK Holzbau.

Everyone has to decide for themselves. I would consider it if the savings reach a certain amount (around 5,000). You will get the structural calculations for the foundation slab and can pass them on as they are. For the wastewater and ventilation pipes, it’s probably a good idea to double-check the measurements on site before the slab is poured. Mistakes often happen, or measurements aren’t taken very precisely.

I wouldn’t handle this through the salesperson but rather find a company yourself.

Jay_Kay schrieb:

What are your thoughts on this, especially considering that these are two separate trades and Bien-Zenker is only responsible from the foundation slab onward?

Usually, you even have a third trade involved: the electrician! You need to have the building’s grounding installed, which must be carried out and documented by a professional. This is necessary for registering your electrical connection. Either the contractor who handles the foundation slab has a qualified specialist, or the electrician responsible for your connection is brought in.

@Jay_Kay: I came across your questions here in the forum. We are currently considering building with Bien-Zenker. It would be really helpful for me to hear about your final experiences—would that be possible? Thanks in advance!