Why building a house almost always costs more than calculated

I have read it now, but it does not say anywhere that it is only binding for all house builders from the end of December 2017!? Is it really binding since 2016 already or only from completion at the end of this year? I somehow don't find that.

I have now read it, but nowhere does it say that it is only binding for all house finishers from the end of December 2017!?

No one claimed that either.

Has it really been binding since 2016 or only from completion, at the end of this year? I somehow don’t find that.

With VDE regulations, they are introduced first. Then a transitional arrangement follows. After that, it becomes binding.

No one claimed that either.

Weberhaus claims that it only becomes binding at the end of December 2017, and that they have only known this since May 2017. Therefore, they have not informed us about it until now.

When I read through the internet, I also come to the conclusion that this regulation has existed for a longer time and that one could inform their customers about the transition period (during which I must have already been at the contract conclusion!?)

Due to new legal fire protection regulations, new switches (!) must be installed in the fuse boxes in the houses for all builders who complete their houses after 2017.

Were these regulations already in effect at the time of signing? Is there a clause in your contract that governs which rules apply to construction and what happens in case of changes?

Were these provisions already valid at the time of signing?

Unfortunately, I don't know that for sure. On the internet, you can find 2 versions:

Version 1 is that this new regulation came into effect in February 2016, but it is only a "regulation" and therefore you do not have to comply with it!?

Version 2 is that all houses built from wood or with timber construction must install this protective device, whose electronics are only installed after the end of December 2017.

A fact independent of the version is that our sales consultant did not mention this during the sales discussion and it was not included in the cost calculation of the house. Because if that is binding, then I expect it to be included in the base price and not to be booked as an "optional feature."

Is there a clause in your contract that regulates according to which rules the building is carried out and what happens in case of changes?

The contract states that changes are possible until the specification of the equipment is finalized, and from then on a change fee is charged.

I have not yet found anything about what happens in case of possible changes by the legislator..

Maybe Weberhaus always assumed that the completion would happen before 31.17 and now it doesn't?