Exterior wall: lime sand + polystyrene vs. hollow brick

The thermal insulation is OK. Hollow bricks without filling are not the best for sound insulation.

36 cm high-perforated bricks without insulation are certainly possible, but

The thermal insulation is OK. Hollow bricks without filling are not the best for sound insulation.

Although a 36 cm brick never comes close to the soundproofing and thermal insulation value of sand-lime stone + 17 cm insulation. Not even close. Does the general contractor or shell builder really do that for the same price? Then I would agree immediately. Unfortunately, I don’t have current prices, but bricks were €80/m3 about 2.5 years ago, XPS €100/ m3. Meanwhile, XPS is probably around €220-230/m3.

According to the construction service description, the walls are built from 24cm sand-lime bricks + external insulation with 17cm PS with ETICS. Alternative - perforated bricks 36.5cm without filling

You can find my collected two cents on the topic with the search term "11ant Steinemantra". Simply put, it says: "use the wall structure that your installer is better at." If he sells structure A:B in a 60:40 ratio, you have the free choice; if it's 90:10, then definitely forget B. Construction defects are created many times more in the workmanship than in the material.