Hey, we have now also decided to build with an architect... The first meeting with one is coming up now... [...] Maybe he will create something for us and despite several changes, we don't agree on a price, for example. Or after a few months of planning, you realize that you just don't work well together... etc...
Then save yourself the restless night, you don’t have to sign anything after the introductory meeting. There is also no early bird or volume discount; the price for each service phase is the same whether you book them individually or the full package at once. Make a contract for the basic evaluation and preliminary design, and later one or several extension contracts. After the first meeting, you have a first impression, and I consider one or two weeks of reflection time before signing the contract to be fair. That means you have the introductory meeting and the reflection period as two stages to form your impression if he is the right one, and the results at the point of a "finished preliminary design" as the third. That should be enough to be clear afterwards if you want to proceed together. After that, I would only make one further supplementary/extension module because, in my opinion, approval planning, detailed planning, and construction supervision are not reasonably separable (without giving up part of the advantage compared to a drafter planning). Between the two contracts/contract parts, you can again take two weeks of reflection time. If afterwards the vote of both spouses is the same, that should be enough security even for the most anxious.