Big house

Good evening,
we had our first appointment last week with a construction company near us and we are so positively impressed that we probably don't need to look for other house builders, but that is another matter...
Today, the architecture department sent me the first sketch of the discussed house type. The longer we look at the floor plans, the more uncertain we become.

Therefore, the question now: We have 2 house types from the company to choose from and we are undecided because with the smaller house, sooner or later an outbuilding (e.g. behind the carport) would be financially possible (approx. 20m2).

About the types:

House A
Single-family house, gable roof, brick-faced, ~125m2, 5 rooms

House B
Single-family house, gable roof, brick-faced, ~114m2, 4 rooms

Both houses cost in solid construction with some extras (shutters, underfloor heating, walk-in shower in the guest WC, etc.) approx. 1700€/m2

We currently have 1 child (approx. 1 1/2 years old), a second is not planned but also not excluded.

I am a passionate musician and occasionally like to game on the PC for half a weekend. So an outbuilding as described above actually makes more sense or could perhaps also be used as a party room?! In addition, my wife likes the layout of the smaller house much better.

I am interested in the opinion of the “collective”.

The option of the smaller house plus an outbuilding will be the more expensive one overall - this option seems particularly attractive to me - not only because of the music but also because of a possible move-out of the children in their late teenage years. Therefore, the entire infrastructure for a bathroom and kitchen should already be structurally provided for in the outbuilding. Since August, we have had a main building and an outbuilding, which are attached to each other but still separate. It is proving very effective that the children (18 and 20) now have their own apartments with their own front door, bathroom, and kitchenette.

I'm interested in the opinion of the "collective"

Build as big or as many houses as you can or want to afford right away, not later. Later it will be significantly more expensive and complicated.

The longer we look at the floor plans, the more uncertain we become.

Given their invisibility, I feel similarly

an outbuilding (e.g., behind the carport) would be financially possible

Legally, however, only to a limited extent: a carport or a garage could be privileged in the boundary setback, but in combination with ancillary rooms might exceed the respective maximum lengths; furthermore, an ancillary room there should not be a living room.

I'm interested in the opinion of the "collective"

Haven't you forgotten to set the variants? How are you supposed to judge two things without knowing them?

The conceptual differences are compared and equivalence is assumed in the execution.