The story is turning into a nerve-wracking ordeal and even the architects apparently are only half-heartedly involved.
The first architect was not even half-heartedly (and even less intelligently) involved, and the current one probably communicates better with the structural engineer, but was unfortunately infected with the botched design.
If you lock yourself into a design and only work on it with a nail file where you actually need a machete, then neither numerous discussants and their suggestions nor a (so far only half) architect change due to the dragged-along design can prevent you from going crazy pretty soon. That then becomes inevitable.
The architect also says that he just quickly drew my suggestion to coordinate whether it fits. This is not detailed planning in the proper sense!
That was already clear to me a round before, at the latest at the garage passage door.
I have not received any floor plans of the old house.
Oh, that’s a pity. But at least the building authority should still have them.
And everyone who was with me on that house clearly said, that has to go.
From the photos, nothing looks neglected or botched to me, at most heating and windows need replacement (and roof insulation too, but that is not relevant in case of an extension), tiles are tasteless etcetera. But not dilapidated substance.
If you want an individual house, then anyway.
On the contrary. Nothing has more potential for individuality than a well-integrated old building stock. Basically, you see that yourself as well, otherwise you wouldn’t be working so gently on the botched design – about which I here repeat my doubts that the existing building could have been planned as awkwardly in terms of quality.