Installations and drilling in high perforated bricks

Hello,

I have searched a lot now but have not found a clear answer.

In the offered construction and performance specification, both for exterior and interior masonry, perforated bricks are specified.
Outside with 24 cm perforated bricks with 16 cm insulation layer and mineral plaster.
Inside depending on whether load-bearing or not, 11.5 or 17.5 cm perforated bricks.

By perforated bricks I understand those that have vertical hollow chambers inside, which are not filled with insulating materials.

My buddy now said whether my planner is crazy with the following arguments
- Interior walls do not have to insulate, therefore perforated bricks are pointless
- Perforated bricks make it difficult to cut installation grooves and drill for e.g. wall cabinets
- Special anchors would be necessary for drilling
- Sand-lime brick is much better suited for interior walls because it is easier to groove and offers better sound insulation
- The latter points also apply to the exterior masonry, installations are difficult and only possible to a limited extent (some kitchen cabinets are supposed to be hung on the exterior wall, also the TV wall on the exterior wall for electrical outlets)
- This also means the exterior masonry could be built with sand-lime brick
- The weaker insulation compared to perforated bricks does not weigh so much because this can be better/easier achieved/compensated by the insulation

My question now: is that correct, is carrying out installations significantly more difficult than with e.g. sand-lime brick?

Either way, I tend to ask the planner whether instead of the 24 cm bricks 17.5 cm ones can be used and for that a slightly thicker insulation (if I understood correctly, insulation yields more insulating effect than brick thickness).
Additionally, we probably want to build with clinker and mineral wool instead. Here too I would prefer a 17.5 cm brick, otherwise the wall would be even thicker because of the clinker.
In summary, Kfw55 standard should still be achieved (controlled residential ventilation planned, whether air-water heat pump or gas is still open).

I installed our windows and doors in the garage recently! It is built from the so-called [hochlochziegel].

You definitely need the right anchors; I initially had some metal ones that spread... but somehow they didn’t want to hold. Then I bought others made of plastic from Tox spread anchors, which were then rock solid.

So at least the interior walls should also be made of [ks]. From a soundproofing perspective, I think I would make everything from [ks]. Especially since you have insulation on it anyway.

You can already secure everything well with hollow bricks, but

1. I find 17.5 cm hollow bricks as a load-bearing wall a bit meager
2. Sand-lime brick is naturally much "better" statically, attachments are easier and more secure to make
3. Sand-lime brick has better properties in sound insulation and heat/cold storage

Why should the outer shell actually also be built from hollow bricks? Why not facing bricks/clinker?

Why should the outer shell actually also be built from hollow bricks? Why not facing bricks/clinker?

? No one mentioned that, right?
Hollow bricks + 16 cm insulation + mineral plaster
or alternatively in the newly planned version with clinker.

oh yes.. sorry, mistake in thinking.

Well, then it does make a small difference in the U-value whether you use [Hochlochziegel] or [KS] as outer masonry.

but just a "small" one?