Hello everyone,
we are planning to build a single-family house with the following specifications:
- one and a half stories
- on a slab foundation
- approximately 125 sqm (1350 sq ft)
- 36cm (14 inches) Ytong blocks (without additional insulation)
- mineral-based exterior plaster
- KfW 70 energy standard
- triple-glazed windows
- heating: gas/solar; underfloor heating throughout the entire house
Regarding a ventilation system, we are unsure about which option would be the most suitable.
Our options are:
- no ventilation system (our builder believes it is not necessary)
- decentralized ventilation system
- decentralized ventilation system with heat recovery
- centralized ventilation system with heat recovery
We have already read a lot on online forums, and the more we read, the more confused and uncertain we become...
Thank you very much in advance for your support!
we are planning to build a single-family house with the following specifications:
- one and a half stories
- on a slab foundation
- approximately 125 sqm (1350 sq ft)
- 36cm (14 inches) Ytong blocks (without additional insulation)
- mineral-based exterior plaster
- KfW 70 energy standard
- triple-glazed windows
- heating: gas/solar; underfloor heating throughout the entire house
Regarding a ventilation system, we are unsure about which option would be the most suitable.
Our options are:
- no ventilation system (our builder believes it is not necessary)
- decentralized ventilation system
- decentralized ventilation system with heat recovery
- centralized ventilation system with heat recovery
We have already read a lot on online forums, and the more we read, the more confused and uncertain we become...
Thank you very much in advance for your support!
B
Bauexperte30 Sep 2013 10:42Hello €uro,
I obviously see this differently! If what you described above were true, I would certainly have a lot of customer complaints. Moreover, sound insulation is really not an issue with a wall thickness of 36.5cm (14 inches).
Regards, Bauexperte
€uro schrieb:
A monolithic wall construction is a compromise when it comes to competing requirements. [...] When building on order, one should be less willing to accept compromises. Although all functional requirements are generally met, the details are less satisfactory: (load transfer (thickness of the load-bearing shell), point load distribution, sound insulation, thermal insulation relative to insulation layer thickness, summer heat protection, etc.).
In other words: it works somehow, but it is not optimal!
I obviously see this differently! If what you described above were true, I would certainly have a lot of customer complaints. Moreover, sound insulation is really not an issue with a wall thickness of 36.5cm (14 inches).
Regards, Bauexperte
Hello,
an alternative would be a cavity wall construction...
We are building, based on our architect’s advice, with the following layers: 17.5cm (7 inches) load-bearing sand-lime brick inner shell, 15cm (6 inches) core insulation with a thermal conductivity of WLG032, and an 11.5cm (4.5 inches) brick veneer outer shell.
This provides good sound insulation, a pleasant indoor climate, reasonably good thermal performance of the wall (about 0.19 W/m²*K), and a façade that lasts, without wrapping the house in plastic.
However, the wall build-up is somewhat thicker at 44cm (17 inches).
Regards,
fragri
an alternative would be a cavity wall construction...
We are building, based on our architect’s advice, with the following layers: 17.5cm (7 inches) load-bearing sand-lime brick inner shell, 15cm (6 inches) core insulation with a thermal conductivity of WLG032, and an 11.5cm (4.5 inches) brick veneer outer shell.
This provides good sound insulation, a pleasant indoor climate, reasonably good thermal performance of the wall (about 0.19 W/m²*K), and a façade that lasts, without wrapping the house in plastic.
However, the wall build-up is somewhat thicker at 44cm (17 inches).
Regards,
fragri
N
nordanney3 Dec 2013 11:52fragri schrieb:
Hello,
one alternative would be a cavity wall construction...
we are building based on our architect’s advice like this: 17.5 cm (7 inches) load-bearing lime sand brick shell, 15 cm (6 inches) core insulation with a thermal conductivity of WLG032, and an 11.5 cm (4.5 inches) facing brick layer.
This provides good sound insulation, a healthy indoor climate, fairly good thermal performance of the wall (about 0.19 W/m²*K), and a durable facade that doesn't encase the house in plastic.
However, the wall construction is somewhat thicker... 44 cm (17 inches).
Regards, Fragri But you are still wrapping your house! You probably don’t have a ventilation system – how do you manage moisture through a 44 cm (17 inch) wall assembly?
Hello,
If facing brick is too expensive, calcium silicate with render can also be used as the outer layer.
In my opinion, this is fundamentally the best wall construction you can choose! Typical external wall insulation systems (EWIS / ETICS) usually do not achieve comparable solar gains of opaque building components.
Usually, cost is the main reason why this optimal solution is chosen less frequently. However, it might be worth considering reducing a few cubic meters of usable space or eliminating unnecessary extras to keep the budget balanced!
Best regards.
fragri schrieb:You have a good architect, although depending on the insulation material used, I might consider ventilating the insulation layer.
....on the advice of our architect, we are building like this: 17.5 cm (7 inches) calcium silicate load-bearing shell, 15 cm (6 inches) core insulation with WLG032, and 11.5 cm (4.5 inches) facing brick as the outer leaf.
If facing brick is too expensive, calcium silicate with render can also be used as the outer layer.
In my opinion, this is fundamentally the best wall construction you can choose! Typical external wall insulation systems (EWIS / ETICS) usually do not achieve comparable solar gains of opaque building components.
Usually, cost is the main reason why this optimal solution is chosen less frequently. However, it might be worth considering reducing a few cubic meters of usable space or eliminating unnecessary extras to keep the budget balanced!
Best regards.
B
brokenlink3 Dec 2013 12:05Explosiv schrieb:
Hi
We have just received the documents for the KFW 70 application. We are building with 36.5 cm (14 inches) Ytong elements. They are prefabricated floor-to-ceiling in the factory and delivered as elements about 1.8 m (6 feet) wide. This eliminates horizontal joints as thermal bridges in the wall.
In combination with a gas condensing boiler, solar panels for domestic hot water, and insulated ground slab, we comfortably meet KFW 70 standards for our 100 sqm (1,076 sq ft) bungalow.
What could be worse about a neatly plastered Ytong wall compared to other walls with polystyrene insulation on the outside?Then the solar system must be very large. Personally, I don’t believe that or my general contractor is too inexperienced.
How much insulation do you have under and on top of the ground slab?
How thick is the roof insulation?
Is there a chance you are using biogas?
@ Euro,
Thank you!
This is certainly not the cheapest wall construction, but probably one of the best.
I was a bit careless with the ventilation gap... you are of course right, but it is also included in the plan. Here it is about 1–2cm (0.4–0.8 inches) that are added. The plan is to use cavity insulation with mineral wool (Kontur KP 1-032).
Thank you!
This is certainly not the cheapest wall construction, but probably one of the best.
I was a bit careless with the ventilation gap... you are of course right, but it is also included in the plan. Here it is about 1–2cm (0.4–0.8 inches) that are added. The plan is to use cavity insulation with mineral wool (Kontur KP 1-032).
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