ETICS, exterior wall, insulation, energy experts' experience reports

Pay attention to the diffusion capability of the ETICS here. The higher the share of the load-bearing Poroton in the total thermal resistance, the more "diffusion-open" the insulation must be. This can sometimes limit the choice of suitable building materials.

Best regards.

.. so basically you can't go wrong if for the aforementioned reasons you prefer a thicker brick wall?

With what kind of cost/benefit factor can I calculate this if instead of the 24 cm brick + 16 cm ETICS that my architect suggests .. I switch to e.g. 30 cm brick + 10 cm ETICS?

Thanks + best regards

Hello,

but what exactly are the advantages and disadvantages of a thicker monolithic wall?

Here, the initial question referred to purely monolithic or stone + ETICS.
A thicker stone plus ETICS usually only makes sense if KFW 55 or lower is the goal; here 42.5 cm stone plus 12 cm ETICS.

How does it look price-wise? --> if you plan a thicker wall and therefore less ETICS?

As described before, for a "normal" house size of about 140 sqm, about EUR 6,000 extra. On the other hand, 36.5 cm solid brick versus 17.5 cm plus 12 cm ETICS is roughly cost-neutral.

Currently, our new build is planned with 24 cm Poroton + 16 cm ETICS

Why?

Best regards

@Bauexperte

currently because the architect says so -->
I'm trying to find out through my many questions whether there are alternatives to what is currently planned without letting costs explode

--> a KfW 55 is intended.

best regards

,,, whether there are alternatives to the current plan without letting costs explode --> a KFW 55 is being considered.

Separation of powers is usually the better approach. However, one must not lose sight of the complex relationship between the building structure and system technology when it comes to an overall economical solution. Initial investment, or the capital service for it, must be in a balanced ratio to the consumption costs. Even a KfW 55 can lead to an economic imbalance.

best regards

Hello,

currently because the architect says so -->
that's what I'm trying to find out through my many questions, whether there are alternatives to how it is currently planned without letting the costs explode --> a KFW 55 is planned.

With conventional house construction, you have to invest a good EUR 20-25 thousand more to realize a KFW 55 efficiency house. This additional cost consists of thicker masonry, stronger insulation, and a lot more technology. So the question - as €uro probably means - is the cost/benefit ratio.

I have often debated this with our structural engineer, and we largely agree that the predetermined focus on the KfW should not be the be-all and end-all. If a single-family house is built according to today's valid technology and standards, it is by no means a bad house; importantly, the outer shell should correspond to the values of a Kfw 70 efficiency house.

The insulation and technology madness demanded from Brussels is a different matter; after all, the ladies and gentlemen there are not the ones paying the bill. The lower the targeted end goal - here e.g. KfW 55 - the more money has to be spent, and therefore not only the question of amortization of the required funds should be questioned but also personally, whether 1 or 2 percentage points of cheaper money are really worth all the technical madness. Is a house built analogously to the valid energy saving ordinance really worse?

I therefore always recommend to our customers to adapt the outer shell including glazing to the KfW 70 requirements (without ETICS). I gladly recommend using renewable technology – where possible a geothermal heat pump, where not alternatively an air-to-water heat pump, and definitely installing a ventilation system. With these measures, a solid and durable single-family house can be realized, whose future residents will not have the feeling of living in a technology-heavy plastic shell.

In the coming years, many new technologies will conquer the market, starting with small wind turbines for the roof and ending with storable modules for electricity. When we reach this point – and the above recommendations were taken into account during construction – it will be possible to retrofit an autonomously functioning house. I am sure then there will be a lot of subsidies to apply for again and – what may be even more important: at that point, the private coffers will have also recovered from the efforts of today's new builds.

Kind regards

Thanks first of all €uro and Bauexperte for the clear and understandable explanation.

Now I would only be interested in what kind of building envelope one should aim for?

The 24 cm + 16 cm ETICS planned for me is, in my opinion, a bit too little masonry and too much insulation.

My problem is just that I actually don't have much knowledge about the whole thing.

Would it still be possible to explain the advantage/disadvantage of a thicker wall with less ETICS instead?

Thank you very much in advance