Is insulation useful with Poroton bricks?

Hello everyone,

we are building a single-family house with architects without KfW.
Poroton bricks (the ones with the cavities) about 35 cm thick and triple-glazed windows are being used.
Underfloor heating and a heat pump are also included.
According to the architect, extra external insulation is not necessary because the bricks have low thermal conductivity.
Only around the roller shutter boxes is styrodur insulation applied.
Since he advised us against a central ventilation system due to the costs and I regret afterwards not having taken it,
I am also unsure about the insulation now.

What is your opinion?

What kind of Poroton is it exactly? There are already big differences.

Then just look for answers here in the forum …. Sorry that you’re getting it now but always answering the same questions is somehow no fun …. You definitely don’t need insulation there. What you do definitely need is a filling … mineral wool or perlite. The sound transmits in these cavities Just way too much … both from inside to outside and within the single-family house.

Ok, filling was never mentioned by the architect regarding soundproofing. Now it is too late anyway. Insulation would have still been possible. We had also specifically asked about soundproofing inside, he said no problem here either. Outside is not so dramatic, we are in a quiet location without through traffic.

Ok, filling was never mentioned by the architect regarding soundproofing. Now it's too late anyway. Insulation would still have been possible. We specifically asked about soundproofing inside, he also said no problem here. Outside is not so dramatic, we're in a quiet location without through traffic.

You're not the only one if that comforts you. We also have a quiet location and it's not like you're going completely crazy but the soundproofing could simply be better (passing cars, children noise). At this stage, make sure you don't have any important interior wall thinner than 17 cm. You can feel a noticeable difference inside. Above all, make sure no water (shower, toilet) is directly adjacent to a bedroom or something similar. If it’s planned differently now, you'll have to come up with something like a brick wall or something similar. But your original question is answered: you definitely don't need insulation (-: and you don't want it either, especially if you don't have a ventilation system.

You don't need insulation on the outside. If you still want to do something, then take the exterior walls at 42cm or 36.5 with filling inside. We also have regular Poroton bricks without filling and the sound insulation is not particularly great but also not so bad that you always notice it negatively. For interior walls, as already said, don't use 11 cm bricks. I would now also go for 17 cm or sand-lime bricks. Otherwise, I think Poroton is a good compromise between sound insulation and thermal insulation.

Ask about your ventilation concept. I guess window rebate ventilators. We also have those in combination with exhaust fans in the wet rooms/laundry room. All in all, acceptable for a residential area.