Architect contract HOAI fee zone and incidental costs

Our architect has presented us with the architect contract according to HOAI. He assigns our single-family house construction project to fee zone 4 with the minimum rate (fee rate).

In addition, he estimates a flat rate for incidental costs of 8%.

Our building plot is a hillside plot (south slope). The slope runs diagonally within the building envelope with a height difference of just under 3m from the "top" corner of the building envelope diagonally to the "lowest" one.

Our question now is whether an assignment to zone 4 at the minimum rate is justified, or how this classification can be objectively understood.

Do you have any tips on this? Another architect we worked with in the initial phase, for example, spoke of zone 3 and the mid-rate.

You should take a look at the [HOAI]. It's actually not that much text; a lot becomes clear on its own. The classification into the fee zones is also described there. I would ask A. to show you his "analysis" of your project so that you can understand where he sees special requirements and whether you also agree with the resulting higher classification.

Theoretically, you could accept it and sue later. But whose assessment the court will ultimately follow is probably up in the air. Therefore, one can really only advise: if it's too expensive for you, find another architect. Single-family houses are mostly found in fee zone III. For "villas" or the like, however, it can of course be different.

Change architect or look for [gu]