ᐅ How much additional cost is expected based on the structural engineer’s calculations?

Could you please post the relevant sections here? Especially the part about the basement and the additional costs?

I still find what they mean by this suspicious. From what I understood, they told you that a bitumen waterproofing was included, then you were supposed to pay extra for a black tank, and now there is even more extra cost for a white tank?

That seems strange to me because I always thought the bitumen waterproofing IS the black tank. And a white tank is not automatically an upgrade: these are two different methods, each with their own pros and cons. One disadvantage of the white tank, as far as I know, is that it is more difficult to construct and must be executed very precisely; otherwise, your basement might not be watertight.

Please correct me if I’m wrong. I’m not 100% an expert on this, but it does sound dubious.

If you have to go through with the contract, it is all the more important to get someone on board who knows about construction and can support you. Trying to handle this alone, with the money you have, seems risky to me. In the worst case, you pay a lot of money and end up with a half-finished house or a building ruin.

Having someone knowledgeable about construction law wouldn’t hurt either, although that may not make things financially any easier. Regarding the contract, the situation seems to be already locked in.

mr.xyz1 schrieb:

We paid 9,000 net for a “real” architect up to the construction planning stage, just to give you a reference point!

With a standard model home, the “architect” obviously has much less to do than with a custom design. It’s piecework.

Lauralila88 schrieb:

I have to say that h&h indicated in the documents that a foundation slab might be needed, which would lead to significant additional costs. But they could have told us beforehand that we are in earthquake zone 3, or we should have informed ourselves better.

The provider is not obligated to inform you in advance about the extra requirements for your specific plot. They only need to clarify what is included in the contract. You are overwhelmed by this and urgently need someone experienced with construction contracts who can tell you what additional costs to expect and whether you have options to cancel the contract, reasonably amend it (if you remove trades, the planned profit usually stays with the company), change the planned construction, or arrange additional financing.

Lauralila88 schrieb:

Now the construction company wants us to formally waive the special termination right—is that legally valid?

Several others besides me have advised you against that.

Now you write:

Lauralila88 schrieb:

We actually had to waive our special termination right as well.

Why? Did you really waive it?

Lauralila88 schrieb:

The documents from h&h stated that it might be necessary to have a waterproof tub, which could significantly increase the costs.

So you probably set aside 50,000 as a contingency budget.

What did the neighbors do? Build without a basement?

hanghaus2023 schrieb:

Then you must have set aside 50k as a risk contingency.

What did the neighbors do? Built without a basement?

Some of the neighbors built without basements, and some built with concrete basements.

hanghaus2023 schrieb:

So, several people besides me have advised against it.

Now you write this:

Why?? Did you really decide not to go ahead with it?

They said they can't start with the detailed construction planning otherwise.