ᐅ ETICS: Structure, Recommendations, Materials, Tips

Hello everyone,

The wall construction for our house build consists of concrete plus ETICS (External Thermal Insulation Composite System) for the basement level (due to the sloped site, it’s basically 2/5 basement and 3/5 garden level with ground-level garden access) and masonry plus ETICS for the ground floor.

We now want to take a closer look at ETICS. We are building according to the Energy Saving Ordinance, but we are not aiming for a KfW standard beyond that.

Starting from the masonry units up to the plaster and paint, what would you recommend here?
Are there significant differences between various ETICS?
What should we pay attention to, and do you have any tips?

Thanks for your help!

Well, I could recommend a ventilated facade—I used this method myself on the upper floor. This involves mineral wool boards laminated with fleece, with wooden battens installed on top. The advantage is that any moisture from inside can dry out easily, and cold wind doesn’t blow directly on the exterior wall because there is always an air gap in between. It also works well in strong sunlight. The previous owner once called it the "wetsuit principle."

I actually like it quite a lot. On the ground floor, we have concrete blocks and Neopor insulation. We are now adding flexible cladding panels there, but visually, I personally prefer the wooden facade first.

Elina schrieb:

These would be mineral wool boards laminated with fleece, and I have wooden profiles on top of them. The advantage would be that any possible moisture from inside can dry out easily, and no icy wind blows directly on the exterior wall, since there is still an air layer in between.

Did you perhaps misunderstand something here (or just phrase it awkwardly)?
A ventilated façade is called that because there is an (airflow) air gap behind the cladding (in your case wood). However, the actual insulation underneath lies directly on the masonry.
If you placed the air gap between the masonry and the insulation, the insulating effect would be lost because cold air would continuously flow in, making no difference compared to an uninsulated wall that is permanently exposed to outdoor air. For the same reason, insulating the cladding in a cavity wall system does not make sense if the cavity itself is not insulated simultaneously.
The "diving suit principle," by contrast, works with a sealed air layer, meaning without ventilation (and thus without drying). Since air still has a significantly higher thermal transmittance than any commercially available insulation material, this is not a viable option in any case.

@Bauherr am L:

An "External Thermal Insulation [S]ystem" (ETICS) is generally the (usually more cost-effective) alternative to a ventilated curtain wall (see Elina). The insulation material is simply plastered over rather than being elaborately clad.
Which of the various systems is suitable for you depends, in addition to cost, on what is "common" in your area (meaning often installed and well known by local tradespeople), as well as your personal preferences regarding appearance, environmental considerations, fire safety, long-term costs, and so forth. Just google the term—it’s faster than waiting for explanations here on the forum.

The cheapest ETICS is made from expanded polystyrene (EPS). The "Neopor" that Elina mentioned is a variant of EPS with slightly better insulation properties. Including plaster, an EPS-based ETICS should cost around €150/m² (about $140/ft²) depending on the region. At our neighbors’ place, part of the façade is currently being finished with a ventilated curtain wall (with rhombus battens), which already costs around €250/m² (about $230/ft²).

@Dr Hix

Thank you for the explanations. However, I am currently focused on specific materials within the ETICS (unfortunately, the ventilated façade was omitted in our case due to cost reasons), starting from the brick through to the render.

Experiences from others could be helpful, for example, if someone has a system that tends to develop algae...

Bauherr am L schrieb:

Right now, I’m specifically interested in the materials used within the ETICS (external thermal insulation composite system).

Use whatever your builder, painter, or whichever tradesperson offers. They all handle insulation—some better (which means more expensive or thicker). Afterwards, you can plaster (and paint) or apply brick slips. In the end, it’s really a matter of personal taste. Everything can look good. Don’t stress, especially if you’re not aiming for a particular standard anyway.

I wouldn’t make such a general statement.
If we are talking about a standard house, the choice usually comes down to EPS or mineral wool. EPS is cheaper, as already mentioned. Personally, if I had to insulate, I would choose mineral-based insulation. You can find plenty of information online about the pros and cons of each system.
From my perspective, it is important with both systems that the plaster is not applied too thinly (especially the reinforcing layer). Unfortunately, this is often where savings are made. If it’s too thin, the plaster can flex on the insulation, which leads to damage over time. (I often see damage cases where the reinforcing layer barely covers the mesh with only about 2-3mm (0.08-0.12 inches) of material. The finish coat is then a matter of taste and budget.)

Find reliable contractors or an external consultant and get professional advice. A good execution of the work is more important than trying to perfect every detail of the materials.