ᐅ Exterior Wall for KfW 40 (+) Standard: With or Without External Thermal Insulation Composite System (ETICS)?

haydee schrieb:

I find it hard to believe that stones will just be dumped at a landfill after 80 or 100 years.

I wonder what will happen to these filled masonry blocks after some time. Are they mineral-filled? Can they be disposed of just like regular stones?

haydee schrieb:

Supposedly, the first externally insulated facade systems (EIFS) made with plastic have been attached to buildings for 50 years without problems.

Not without problems everywhere. On renovated houses, you sometimes see these 5cm (2 inch) spots. Those are the plate anchors used for fastening. If the entire facade isn’t repainted every few years, it looks really bad. Nowadays, the anchors are recessed deeper, then a cover made from insulation material is applied on top, or in new buildings, no anchors at all if allowed by the manufacturer’s specifications.

haydee schrieb:

EIFS made from Neopor/plastic only burn once exposed to air. So windows explode, render peels off, flames break through, and after about 20 minutes the facade catches fire.

Walking down my street, I see a house where the render peeled off over the EIFS and there are open areas near the windows. Also, some edge zones at the junction with the adjacent terraced house were only roughly rendered. This reminds me of a story where the previous owner tried to burn shrubs right next to the facade. Occasionally, unlikely individual cases chain together...

haydee schrieb:

Supposedly, special anchors and screws exist for lamps, mailboxes, and similar items. A former neighbor isn’t satisfied. During construction, firmer material can be installed at lamp outlets.

Correct, but with mineral wool insulation, you have to drill through to the wall. Anchors won’t hold in the insulation wool at all. Anyone not skilled will have a tough time trying to screw anything into the facade.

pagoni2020 schrieb:

For example, we chose continuous exterior insulation above the rafters, and that

May I ask what percentage premium you paid for the continuous exterior insulation?

Kati.com schrieb:

May I ask what percentage extra you paid for the structural insulation above the rafters?

Unfortunately, I can't give you a clear figure since some costs were offset against others, and we supplied the materials ourselves, so it’s hard to say. From what he generally said, there’s no huge difference, and we wanted it that way anyway. I don’t have individual cost items.

Based on what I sometimes read here, it will depend on how your contractor calculates it and whether they are interested in doing it. Ours is willing to build the house this way or sometimes a bit beyond standard, which you can tell, and I think/hopethat he prices it fairly.... 🤨

In any case, you can apply a solid layer of PUR/PIR insulation with the best thermal conductivity values on the outside. At times, the energy consultant even calculated with 30cm (12 inches), but that was adjusted based on other measures.

That’s why I say it’s a package of measures depending on various factors, such as the extra cost from my chosen builder and my own design preferences. Since we also opted for a timber facade, there is insulation underneath that, helping us reach this KfW standard.

This was more of a process we hadn’t originally planned. We initially aimed to meet the energy savings regulations; through available, affordable adaptation options, we ended up very close to KfW40Plus, and our energy consultant even encouraged us to implement it.

So, in a way, it was more of a "from one thing to another" outcome.

pagoni2020 schrieb:

Unfortunately, I can’t tell you exactly, since he deducted one thing and added another, and we provide the materials ourselves, so it’s hard to say. According to his general statement, there isn’t a significant difference, and we wanted it that way anyway. I don’t have individual itemized costs.

Based on what I sometimes read here, it will depend on how your contractor calculates things and whether they’re willing to do it. Ours is willing to build the house as specified, or sometimes slightly different from the standard, which you can tell, and he seems to price that fairly, at least that’s what I see/hope…. 🤨

In any case, you can apply substantial rigid PUR/PIR insulation boards on the exterior with the best thermal conductivity values (WLG). In some places, the energy consultant even suggested 30cm (12 inches), but that was balanced out by other measures.

That’s why I say it’s a package of measures that depends on several parameters, such as the additional costs of my chosen company, my own design preferences, etc. Since we also decided on a wooden facade, there is insulation beneath that as well, which allows us to achieve the KfW standard.

However, that was more of a process that wasn’t originally planned. We intended to build according to the Energy Saving Ordinance, but with the available affordable modification options, we ended up close to KfW40Plus. The energy consultant also encouraged us a bit to implement it.

So, in that sense, it was more of a “from the blue” result.

I really hope you’re not planning to use rigid insulation over the rafters made of PUR without special measures. For good reason, that is no longer considered best practice because it offers no sound insulation. Otherwise, you can expect to end up suing your architect like many others have before you...

But if that’s the case, please clarify that you’re combining it with insulation between the rafters.

Bookstar schrieb:

I really hope for your sake that you’re not planning to use PUR rigid foam insulation above the rafters without any special measures. For good reason, this is no longer considered the state of the art, as it offers no sound insulation. Otherwise, you might as well prepare to sue your architect like many others before you...
But then please mention that you are combining it with insulation between the rafters.

What sources are there that say this is no longer state of the art?
What lawsuits?
What do you mean by special measures?
Soundproofing from the outside?
Between-rafter insulation is not planned, instead there will be an exposed rafter roof structure.
Please share any concrete information on this – I’m eager to hear more.

Solid construction is just one building method, regardless of where the insulation is placed.
From an ecological and energy efficiency standpoint, timber frame construction is a viable alternative even for multi-family buildings.
Especially in metropolitan areas, which for us is the Rhine-Main region, every square meter of living space counts when planning due to land costs.
Often, additional living space cannot be created differently on existing buildings due to weight restrictions.
Fire protection and sound insulation (e.g., near airports) are solvable issues today.

When it comes to durability, I consider skilled workmanship very important. Often, I only approve a trade after 2-3 attempts during site supervision.
Special construction methods, such as fully curved exterior walls, are completely excluded.