ᐅ Which Type of Brick or Block to Use for Solid Construction

Created on: 4 Mar 2019 16:06
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Petey01
Hello everyone,

We are currently planning the construction of a solid brick house (urban villa with 160 sqm (1722 sq ft)), with two full floors plus a basement, without KfW funding. The standard option with the general contractor includes 36.5 cm (14 inches) porous S9 bricks without integrated insulation (Lambda value 0.09) with a two-layer plaster, no external thermal insulation composite system (ETICS) => U-value 0.23 W/(m²K).

Now we have the option to choose TV7 bricks (Lambda value 0.07) with integrated insulation instead, for an additional cost of nearly 5000 euros => U-value 0.23 W/(m²K).

Is this additional cost worth it?

It is also not yet decided whether to install a ventilation system with heat recovery (additional cost 7000 euros). Our concern here is not the comfort it provides but really the efficiency and cost-benefit factor. Is a ventilation system really necessary to avoid moisture problems? I am not asking about the comfort of ventilating three times a day, but rather whether anyone has experienced mold issues in a relatively new house due to the absence of a ventilation system, especially if windows were only opened once or twice occasionally.

Thank you in advance for your information and opinions.
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Tego12
23 May 2019 09:35
All are low-cost providers with inexpensive walls. The house naturally still stands, but sound insulation is poor in all of the mentioned cases.
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Nordlys
23 May 2019 09:40
Both are equally good or rather equally bad. We live in a Ytong house. I am very satisfied with the wall. Hardly any cracks, nice and warm, easy to attach things to (wardrobes, tall cabinets, and so on) – only the block is somewhat sound-transmitting, which does not bother us since we live in a dead-end street in a purely residential area.
Milchmann23 May 2019 11:56
What does "hellhörig" mean? Is it about sound transmission between the rooms inside or from outside? We are also preparing to build with 36cm (14 inches) Ytong blocks on the exterior and 11.5cm (4.5 inches) on the interior. This issue is still on my mind.
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guckuck2
23 May 2019 12:15
Use sand-lime bricks for the interior walls. At least if you have kids.
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Nordlys
23 May 2019 12:29
I want to describe the feeling more closely. Inside. When I watch TV in the guest room and she is in the living room, it doesn’t bother her at all. But if one of us wants to listen to music a bit louder, the other would notice it. From outside, you can clearly hear the garbage truck, a car a little bit. Birdsong is not heard at all. K.
Milchmann23 May 2019 12:30
Is it really that bad @Nordlys?
My main concern is noise coming from the bathroom, specifically whether every conversation and movement can be heard.

Sand-lime brick is disproportionately expensive with the general contractor – likewise, 17.5cm (7 inches) Ytong interior walls already add an extra 6,500€ in costs...