Change of external dimensions after building permit?

On the choice of wall construction: According to the building permit, we had to provide proof of a certain level of sound insulation because the construction project is located on a state road. Therefore, not every type of brick was suitable for the execution of the exterior walls. According to the sound insulation certificate that was also created, the wall construction shown above provides the required sound insulation.

I would leave the structural masonry shell as it is under these overall circumstances (also in the position) and rather upgrade the insulation to a better thermal conductivity group (in the previously planned thickness), or does it perform worse in terms of sound insulation?

I would have to check which value according to the [Schallschutznachweis] is required for the insulation in this respect. I actually had the idea as well, but then the question arose for me whether I am allowed to deviate from the [Wärmeschutznachweis] regarding the thickness of the insulation by using a better thermal conductivity group. Would the [Wärmeschutznachweis] then have to be revised?

This is stated in the sound insulation certificate for the wall structure

Our architect thinks that we can simply adjust the exterior dimensions of the house (previously: 8.49 m x 8.99 m, adjusted: 8.56 m x 9.06 m) accordingly and that the house would only have to be shifted by 4 cm on one side of the property, since a boundary distance of 3 m is planned here so far. The boundary distances on all other sides would also be maintained with the changed exterior dimensions. No further measures, other than adjustment by a surveyor, would be necessary.

That would be the most obvious change for me. Nothing would have to be changed inside. If you compress this design – even if it's only 7 cm – you have to take them from somewhere. The 2.51 RBM in the utility room are just tight, especially if you possibly want to place four 60 cm cabinets side by side there. The hallway is also cut close with the staircase; you practically stumble over the stairs before you’ve even entered, and in the shower-WC the shower partition then collides with the window. 2.26 m may not be little, but not with this toilet-, window-, and shower arrangement. Additionally, tiles also contribute to about 5 cm being lost beyond the plaster. An internal change might be easier without amending the building application, but it rather impacts the functionality of the house.

I summarize: The architect advocates (1) for an adjustment of the external dimensions, you and the construction company for (2) the setback of the walls inward, and my suggestion (3) was an upgrade of the EIFS while maintaining the dimensions.

But regardless of whether the external dimensions are adjusted or not, the construction company wants new plans from our architect. Otherwise, additional costs arise due to the changed external dimensions and they want to make an additional contractual agreement in this regard.

My question is, does the adjustment of the external dimensions and the corresponding positional shift still lie within any tolerance limits or do we need a supplementary approval / amendment to the building application for this?
What other measures are necessary when adjusting the external walls either while maintaining the external dimensions or adjusting the external dimensions? Does a new structural calculation have to be done?

Unfortunately, our architect is now on vacation for an extended period and the construction company wants to start with the foundation slab the week after next.

(1) and (2) require an amendment due to the change of the dimensions and the position (1) or only the dimensions (2), (3) requires the recalculation of the thermal and sound insulation certificates. The structural calculation only has to be redone for (2), not for (1) and (3). The dimensions from the mason’s perspective (i.e. concerning the house before the installation of the insulation) only change for (2), for (1) they are only shifted linearly, and for (3) not at all. In this respect, the construction company should calm down (and afterwards, of course, tar and feather the architect for going on vacation at an inopportune time). The foundation slab must be adjusted with regard to its absolute position and the position of the penetrations for drainage and house connections in case of (1), only for the latter in case of (2), and not at all in case of (3).

My Plan A would therefore be the improvement of the insulation with the same thickness (all dimensions and positions remain the same) and my Plan B, to implement the thermal and sound insulation calculation with the thicker insulation as indicated in the site plan and floor plan, and the corresponding linear shift of the house. Moving the walls inward requires a new structural calculation and leads to cutting stones, although in this case at least without shoddy pockets.

If I were you, I would also show the other remaining plans here, the architect probably has slacked off in other places as well.
Are you actually building with Poll as originally intended?