ᐅ Structural Assessment of Openings for Electrical and HVAC Installations

Hello everyone,

I am currently building a semi-detached house and would like to ask the forum community for their opinion regarding the electrician’s work and the planned modifications for installing an air conditioning system.

Work done by the electrician so far:

• Large opening in the exterior wall (36 cm thick (14 inches)):
• A very large vertical slot (almost 18 cm deep (7 inches)) running through all floors has been created in the exterior wall to route cables to the distribution panel. The wall is load-bearing and also important for thermal insulation.
• The electrician has assured me that this opening does not affect the structural stability and will be filled later with insulation material (foam).
• My question: Is it common or acceptable 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 chases for sockets and lighting:
• Throughout the house, smaller vertical chases (approximately 3 cm x 3 cm (1 inch x 1 inch)) have been made in the walls for cable routing. These chases are present in both load-bearing and non-load-bearing walls.
• Is it normal to create such chases, or should extra caution be taken with load-bearing walls?

Request from the air conditioning technician:

• New chases for air conditioning:
• The air conditioning technician wants to create an additional vertical chase (about 5 cm x 3 cm (2 inches x 1 inch)) for each indoor unit.
• These chases would be made in the load-bearing walls to install the pipes and hoses.
• Drill holes for air conditioning:
• The technician also requests permission to drill holes in the exterior walls to route the lines and pipes of the air conditioning system outside.
• I am wondering whether these drillings could affect the stability or insulation of the exterior walls and if special measures or inspections are necessary.

I am commissioning this independently from the general contractor. Should I obtain explicit approval from the general contractor before making these chases? Or should I hire an independent engineer to assess this?

I look forward to your assessments and advice!

Thank you in advance!

I have no structural concerns regarding your project; however, considering your humorous general contractor, I find it quite bold to arrange subcontracting before the shell construction inspection.

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Yes, I also wanted to avoid that, but the rough installation of the air conditioning system won’t look neat if it is done later.
The heating engineer doesn’t seem to have much experience with installing air conditioning systems, and I want to have the entire air conditioning system from a single source.

11ant schrieb:

Add the inspection of the shell construction.

What exactly is meant by the shell inspection? Having the shell construction checked by an expert?

Bayernbors schrieb:

What is meant by the shell construction acceptance? Having a structural inspection done by an expert?

No, I meant your approval of the progress made so far in fulfilling the construction contract – does the general contractor only want that at the very last hammer blow?

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11ant schrieb:

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

Hi,

with a general contractor build, there are actually no intermediate inspections scheduled. Strictly speaking, the general contractor can do whatever they want the whole time; the final acceptance is at the end, and everything has to be correct then.
That’s why the expert regularly visits, to document the intermediate steps.

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