Structural assessment of the slots for electrical and air conditioning systems

Hello everyone,

I am currently building a semi-detached house and would like to ask the forum community for an assessment regarding the electrician's work and the planned modifications for the installation of an air conditioning system.

Previous work of the electrician:

[*
Large opening in the exterior wall (36 cm thick):


[*]A very large slot opening (almost 18 cm deep) was created through all floors in the exterior wall to lay cables to the distribution box. The wall is load-bearing and also important for thermal insulation.
[*]The electrician assured that this opening does not affect the structural stability and will later be filled with insulation material (foam).
[*]My question: Is it common or normal to make such a large opening in a load-bearing wall? Should a structural engineer be consulted here, or is the electrician's confirmation sufficient?


[*]Vertical slots for sockets and lighting:
[LIST]
[*]Throughout the house, smaller vertical slots (approx. 3 cm x 3 cm) were made in the walls for cable routing. These slots are located in both load-bearing and non-load-bearing walls.
[*]Is it normal to make such slots, or should one be cautious with load-bearing walls?

Request of the air conditioning technician:

[*
New slots for air conditioning:
[LIST=1]
[*]The technician for the air conditioning wants to create an additional vertical slot (approx. 5 cm x 3 cm) for each indoor unit.
[*]These slots would go into the load-bearing walls of the house to lay the pipes and hoses.


[*]Drill holes for air conditioning:


[*]The technician also requests permission to drill holes in the exterior walls to lead the lines and pipes of the air conditioning to the outside.
[*]I wonder whether these drillings could affect the stability or insulation of the exterior walls and whether special measures or inspections are required for this.

I am commissioning him independently of the main contractor; should I obtain explicit approval from the main contractor before making these slots? Or should I hire an independent engineer to carry out such an assessment?

I look forward to your assessments and advice!

Thank you in advance!

For your project, I have no structural concerns, but given your humorous [GU], I find it bold to add subcontracting before the acceptance of the shell construction.

Yes, I also wanted to avoid that, but the rough installation of the air conditioning will not look good if it is done later. The heating engineer does not seem to have good experience with installing air conditioning systems, and I want to have the entire air conditioning system from a single source.

Abnahme des Rohbaus zu ergänzen.

What is meant by the acceptance of the shell construction? Having the shell inspection carried out by an expert?

What is meant by the structural shell acceptance? Having the structural shell inspected by an expert?

No, I meant your approval of the construction contract fulfillment achieved so far - does the general contractor only want that at the very last hammer strike?

No, I meant your approval for the construction contract performance achieved so far - does the general contractor only want to have that at the very last hammer blow?

Hey,

with the general contractor construction, no interim acceptances are planned at all. Strictly speaking, the general contractor can do whatever he wants all the time, acceptance takes place at the end and everything has to be correct then.
That’s why the expert regularly visits to document the intermediate steps.

Regarding the slots topic - no idea what is correct according to DIN, but ours looked pretty much the same as yours. I have seen worse here in the forum.
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