Dream plot, but TAFF house - first mistake already made

So according to their website, the exterior wall is as follows:

On the website, I mainly see no congruence between the described wall structure and the image for it. The material thickness ratios in the image are partly completely different, and I do not recognize the "installation layer" there.

Assignment declaration available. The house construction guide says one should in return demand a performance bond for the entire construction sum. I do not find something like that in the contract. I do not know what that means overall,

This assignment declaration means that the provider wants to draw the money from the client directly from his financing bank in the amount of the total price; I do not read any reasonable completion guarantee against that.

This assignment declaration means that the provider wants to withdraw the money from the builder's financing bank to the full amount of the price directly, and I do not read a reasonable completion guarantee against that.

The guide states:

If the company insists on its own requirement, then only agree to it if in return a performance bond for the entire construction sum is provided. Remember, only simultaneously and through a notary.

And further down:

[One should not be misled by:]
- Written assurance of the completion of the construction work by the company (That is nonsense, the company already does this through the contract)

So a completion guarantee is not the same as a performance bond, and the latter would in turn have to be countersigned by a notary?

So a completion guarantee is not the same as a performance bond, and this would have to be countersigned by the notary?

Completion bonds can be obtained in three ways: through a bank, or an insurance company, or by involving a notary who manages an escrow account for this purpose.

The purpose of the bond is
1) that in the event of damage, completion can be secured for the builder without him practically paying twice; if necessary, by means of a compensation payment from which he can cover replacement performance;
2) not having to assert the claim for completion against the insolvency administrator if the provider "goes bankrupt."

A "guarantee" titled, unsupported oath "we commit to fulfilling our contract" is a worthless joke.

Taff Haus advertises with bargain prices but has a strange way of presenting itself. You are addressed informally. It’s like at Ikea, only there the informal address feels more serious. You get a house configurator that gives you a great price, but not a word about what is built how. And by whom! Be on your guard, hire an engineer as a consultant for a fee.
I wouldn’t be so afraid of the country either. You can include in the notary contract that the plot is not toxic.

But unfortunately, those real bargain prices are really not what you get, especially when compared to the "good" FTH manufacturers...
Moreover, we had a salesperson from Taff with whom you simply don’t want to complete a house purchase, unless you see it like shopping at Ikea and still don’t quite know what you’ll end up with...
Taff Haus was our first developer we had contact with, and right at the start of our search also the most incompetent... Maybe it was just the salesperson, who is no longer active in our area, because the product itself isn’t actually bad.
But there were things with us that are just not okay, especially with FTH, for example the chimney requirement ("...it comes free, that’s just how we bought it...") whether you want it or not, and when changing load-bearing but also non-load-bearing interior walls, we were told that this is not so simple and the floor plans are already optimal... The final price back then really shocked us, and we only came to Taff because they supposedly had a plot on offer that we liked, but which they actually weren’t allowed to sell... Meanwhile, there is another show house here, but the other plots are still not built on after a year...

Regarding selections, there is a cooperation with Bauhaus where you can then choose the materials...

As already noted by other users, the payment terms are also very questionable, 15% after submitting the building application, WHAT? Sorry, but nowadays that is an interest-free loan they get from the builders. Overall then 30% after completion of their quite inexpensive foundation slab. That costs almost 100,000 for a 300,000 EURO house? Since they are still very new to the market, you really have to think 100 times if you want to put up with that... especially since we were always told that Mr. König, as owner of the entire real estate group, now wants to enrich the single-family home market with his experience after many very successful decades and therefore founded Taff. That is of course complete nonsense, because he only thinks about profit, and this has been rising especially in single-family homes over the last 5 years and will certainly remain at least constant in the medium term...

I don’t want to speak badly of this company, but you should already notice differences in the pure comparison that actually should keep you from building with this company. The configurator alone is quite poor when you consider that you basically only get a shell house including materials and the labor costs are almost the same, at least for the interior finishing including heating and so on...

With the "assignment declaration" one effectively relinquishes all warranty / performance rights.... without this disadvantage being adequately compensated (therefore ineffective).

The bank effectively becomes a self-service store for contractors.

Guarantee: If it is not "on first demand," one effectively cannot access it (without acknowledgment or judgment).

And: KfW funding 431 for burglary protection is not available for new buildings, only for existing ones.

Our bank (Hypo) has excluded the assignment in the contract.