The planner does not perform any calculations according to DIN 276

She has not submitted any document or report about what the construction has cost now, and that cannot be?

She has not submitted any document or report about what the construction cost now, and that can't be right?

Of course, that should not be the case. But I did not understand what this breakdown is supposed to bring you if you already know exactly what cost how much? If I were in your place, the question of a breakdown from the architect would be secondary. The main question would be whether you have legal claims for compensation. Only a specialized(!) lawyer can clarify this. The main question would also be how much work you want to invest to achieve which exact result. I still lack clarity from your side about what exactly the goal is. Just receiving this breakdown is not an end goal, or am I mistaken?

Mainly the question would be whether you have legal claims for compensation.

I have already recommended a few pages earlier to refer to the basic services of the HOAI... So yes, if service phase 8 is commissioned, the cost determination must also take place – it is also paid for by the client (or at least the architect wants to get the money – regardless of what they have delivered).

I already recommended a few pages ago to consult the basic services of the HOAI... So yes, if service phase 8 is commissioned, the cost determination must also take place - it is also paid by the client (or at least the architect wants to get the money - regardless of what she has delivered).

And from this, a construction cost overrun etc. could possibly be explained How far that goes I don’t know / however, right now my only approach against this woman is to demand the services, since she is already calling for the final invoice - and with the payment of this, the architectural services would also be accepted

I did not build with an architect, so I am completely unfamiliar with the HOAI.

The first thing I noticed is that when I add up the percentage figures in the contract, I come to 87%. Not all service phases are agreed upon, are they?

Furthermore, it would probably be necessary to check which version of DIN 276 is actually to be applied. The contract is certainly already several years old.
Search for this:
"Do costs have to be determined according to the new DIN 276 from now on?"

If I understand correctly, there are major differences between the old and the new DIN 276. If the old one is still to be applied here, the cost estimate in service phase 2 must be made according to DIN 276. (According to #7, this probably happened.)
For the determination of the billable costs, this could also apply, but apparently, deviating from what is stated in the contract, the billable costs were determined according to the Winden construction table, i.e. not according to the actual costs.

And again regarding the cost explosion, your father, as you claimed, received a cost estimate according to the individual trades with minimum and maximum. If the mason’s offer is so much more expensive than the maximum estimated there, then one could have already intervened back then and pulled the emergency brake. It has been widely reported in all the media that construction prices are exploding and craftsmen are submitting defensive offers.
If now, after 4 years, the daughter (who is not a contracting party) comes with loud accusations and questions everything from the last 4 years that was previously approved and signed by the contracting party, then I would also let her off the hook.

I originally just wanted to know if the architect’s claim is correct that she does not have to create any calculations according to DIN 275

If necessary, also with the general statement that this DIN is unknown to her.

And from that, a budget overrun etc. could possibly be explained

But you already know that the budget was exceeded, right? Even if an estimate "appears" now that runs at 650k, your father did not know it.

And since obviously I do not think enough like a lawyer, as I still do not understand what use the document has (except that you should pay for its creation), my opinion remains to simply hire a lawyer.