Cost of house construction with an architect

On the topic "Building with an architect": is it actually possible that even before the repeal of the EU-wide applicable HOAI, fixed prices below the minimum rate were agreed upon with architects? Because acquaintances said that their architect fees at the time were well below the minimum rate intended for the construction sum according to HOAI?

What do you actually think about the idea of not agreeing on a fixed price with the architect (i.e., a price based on the construction sum), but paying them according to effort? Is this common?

By fixed price I meant the price for the house, not for the architect's services. One has to distinguish that for the TE. We did not pay our architects according to HOAI, but based on effort. Whether that is common, I don't know; HOAI is not usual here in the region in the single-family house sector because it is too expensive.

We did not pay our architect according to HOAI, but based on effort.

Do you understand "based on effort" to mean that he said beforehand "I will need this much time and it will specifically cost xy," or that he gave an approximate value (like a cost estimate) and only stated his exact price after completing the last activity?

The architects were from the wider circle of acquaintances, so my experience with cost structuring doesn’t really help here.

However, I know that they fundamentally do not bill according to HOAI because their clients here do not want to afford that. For certain service phases, they have fixed prices as far as I know, significantly below HOAI. I think that strongly depends on the region. When we looked two years ago, the GUs were in the range of €1500-€1600 for turnkey catalog houses; nobody pays an extra €50k to build with an architect. In the south, where the GUs are more expensive than the prefabricated house builders, it might be different again.

Um... maybe not with the architect, but the costs arise at the earliest with the structural engineer, at the latest during construction.

The question is always when the changes are made and what they cost in terms of time, material, and organization. With system providers, who generate part of their margin through standardized processes, the organizational effort can be very unwelcome and therefore the surcharge significantly higher than would be justified by material and time alone.

By fixed price I meant the price for the house, not for the architectural service. You have to differentiate that for the TE. We did not pay our architect according to HOAI, but based on effort. Whether that is common I do not know, but HOAI is not usual here in the region in the single-family house sector because it is too expensive.

I only know it that way too.
A fixed price is agreed with the architect beforehand that is based on effort and not on costs.
Hardly anyone uses HOAI for that. With all the catalog houses and general contractors, these are simply not competitive in the single-family house sector.