Single-family townhouse villa in South Hesse

If it is only about bids, phase 2 might be sufficient and very likely phase 3. However, an architect who does not offer all phases would be suspicious to me.

The architect offers all phases.

If it is only about offers, possibly phase 2 is sufficient and very likely phase 3.

If one takes the vast difference between tender and request for quotation lightly and a budget overrun of over 20% (or over 40%) is no big deal, then the results of phase 3 (or phase 2) are completely sufficient as a basis, yes.

An architect who does not offer all phases would, however, be suspicious to me.

And to me just as much those who offer phases up to and including phase 9 for owner-occupied single-family houses.
The mandate scope "phase 1 to 4" is the clever guy’s favorite. Due to numerous customer requests, even architects who are actually somewhat competent include that in their offer. Many home builders want it exactly like that: approval planning and then play Russian roulette with it. They need the thrill and are happy to pay more if they can simply continue believing afterward that otherwise it would have been even more expensive.

Phase 5 can potentially pay off – but hardly if one proceeds foolishly afterward. Then it is nearly useless and saves you almost only some drywall bumps. See also:

Already the building application planning (phase 4) does not meet the requirement of sufficient accuracy. The design planning (phase 3) is even further from the building application planning by at least the drainage planning (as well as the heat demand calculation, ventilation concept and the like). Simply put, at the end of phase 4 you only have "the house of Nikola__", and at the end of phase 3 even only "the house of Niko____".

If you take the huge difference between tender and request for quotation lightly and a budget overrun of over 20% (or over 40%) doesn’t matter, then the results of phase 3 (or phase 2) of the service phases are totally sufficient as a basis, yes.

No idea what you’re talking about. I meant a first draft with which you, for example, obtain a price offer from a general contractor or prefabricated house supplier. Back then, we managed that with a standard floor plan from the catalog. Of course, it always depends a lot on the plot and the circumstances.
At a tender, I wouldn’t be anywhere near that point yet.
If it then comes down to individual awarding, doing so without phase 5 of the service phases is, of course, harakiri.

No idea what you are talking about. I meant a first draft with which you can, for example, obtain a price offer from a general contractor or prefab house supplier. [...] At the point of a tender, I would be far from ready.

The key decisions (often with the side effect that the house has to be adjusted to the budget before the actual design) are made with the preliminary design, i.e., before design phase 3. The tender only happens after design phase 5. There can easily be almost half a year in between.