ᐅ We are planning to build a house and are looking for advice and shared experiences.

Hello everyone,
Since we have an idea about certain things and have already done some research on Google, knowing that everything is a matter of personal taste, we still have a few questions.
Our house should have approximately 170 sqm (1830 sq ft) of living space.
Upper floor with knee wall
No basement
It will be a solid construction house.
We are already debating the choice of blocks. But I think Ytong stands out, based on online research and many masons we have consulted.
Our planner says that building with Ytong meets the current standard for thermal insulation.
Do you also think that is sufficient? Or would additional insulation still be advisable despite using Ytong?
The exterior will be plastered as well.

Now regarding heating.
We want underfloor heating downstairs and in the bathroom upstairs. No heating in the bedrooms, where we might consider cork or something similar, plus radiators naturally.
We decided to go with gas and want to add solar panels for domestic hot water.
We have already ruled out an air-source heat pump due to cost reasons.
We might also want a water-backed fireplace.

Our questions:
Is underfloor heating alone enough to heat the house during winter? If not, wouldn’t it be better to skip it and only install radiators? Running both means basically double costs in the end.
In our rented apartment (25 years old), the underfloor heating is not sufficient without radiators. That’s why we wonder if it might be because of the building’s age.

Which gas heating system would you install?
Would you install a mechanical ventilation system with heat recovery?

These are our current questions.
I hope someone can help us before we get started :-)
Thank you

Regarding heating:
Underfloor heating is sufficient if properly sized. However, it is best to choose either only radiators or only underfloor heating, since different supply temperatures are required, or you need to use appropriately large low-temperature radiators.

Gas and solar combined with suitable Ytong stones would have worked for us as an energy efficiency regulation-compliant house. Since we went with a heat pump and ground loop collectors instead, we achieved the KfW70 standard.
With the recent adjustment of the energy efficiency regulation, I am not sure whether Ytong + gas + solar will still be sufficient in the future, or if controlled mechanical ventilation or other measures will become necessary.

Are Ytong blocks sufficient for good sound insulation? I mean so you don’t hear everything from outside, like shouting, playing children, etc. :-)
Did you use only the Ytong blocks without any additional insulation?

Certainly, sand-lime brick provides better sound insulation – but if you don’t live next to a railway and aren’t aiming for 15 cm (6 inch) thick masonry, Ytong is probably fine as well. Masons like building with it because the blocks are lightweight 😀

Are you planning to add brick cladding?

For heating, it makes sense to use one system consistently, considering the mentioned supply temperature – options include large-area radiators operating at low temperatures, wall heating, etc.

Yes, underfloor heating is sufficient.

We also considered a water-based fireplace, but it doesn’t quite fit the overall concept, it’s a considerable investment, and you’d need to chop wood.

We have now been living for just over 3 months in a house made of aerated concrete.

I have the impression that certain sound waves pass through the masonry quite easily, while others are less noticeable. For example, I was surprised when a fireworks display took place at a considerable distance. It sounded as if you were outdoors in the open air.

Similarly, construction vehicles can be heard quite clearly. On the other hand, the many children in the housing development or the regular cars in the residential area are barely audible.

For a railway line or a major road nearby, I would only recommend aerated concrete with additional sound insulation measures.

Good morning,

Musketier schrieb:

For example, I was startled when fireworks went off at a distance. It sounded as if you were standing outside in the open air.

That should not happen, because aerated concrete also comes in different densities. For exterior walls, denser blocks are usually used.

Regards, Bauexperte