Completely renovate Streif bungalow prefabricated house

Hello everyone,

my girlfriend and I live in a Streif Haus bungalow house with a hip roof from 1974. Since a new build would be too expensive for us (an old cellar would not support a new house either), we want to completely renovate our bungalow from the ground up. What is especially important to us is the facade including new windows and doors, so that the heat doesn’t just fly out in the winter.

I now have two offers (more to follow). Both offer to remove the old insulation, treat the stud frame, dismantle the old Eternit panels, and install new insulation. One company offers an external thermal insulation composite system with external plaster, and the other offers an Isoklinker. Both are roughly the same price (around €38,000, approx. €330 per sqm including installation).

Yesterday I spoke with a third provider and when I asked if they also work with brick slips Isoklinker, he said that should not be done because they are very susceptible (the joints) and there could be problems in the wall because moisture cannot properly escape. Therefore, they would plaster.

Today I then spoke with an expert (through a short contact at work) and he asked why we don’t just leave everything as it is and only fully brick the facade. That would be much cheaper, after all. He said it would cost about €130 per sqm plus foundation. But then I would still have the contaminated waste in the wall. What are your opinions on this?

My girlfriend and I lean towards the bricks because it looks quite nice, but if it really is susceptible, then of course we would refrain from it. Thanks for your assessments!

Fachwirt

Thank you for your assessments!

The expert's statement makes the most sense to me; on the other hand, I am not exactly an expert in prefabricated houses. This is also not a question for a forum, but rather for an expert/architect who is familiar with prefabricated houses and their particularities; who can support you professionally and, if applicable, regarding funding. Rhineland greetings

Primarily, it is important to us to remove the contaminants from the walls (Asbestos, PCP, Formaldehyde...) and of course also save some heating costs. If I only apply brick slips and leave the waste inside, I have gained nothing in terms of contaminants. Likewise, many old prefabricated houses have a musty smell because the old materials used react with each other...this has not been the case with us so far but can happen at any time, which is another reason why the old insulation should be removed.

Both offers would be eligible for up to €50,000 KfW funding; the providers have already submitted the corresponding calculations. The "Isoklinker" option has already been approved by an energy consultant.

I asked this question here because there are surely people who can help me here based on their experience.

First and foremost, it is about getting the pollutants out of the walls (asbestos, PCP, formaldehyde...) and of course also saving some heating costs. If I only brick-veneer and leave the garbage inside, I haven't gained anything regarding the pollutants.

I'll be heretical now – if I follow this whole fuss about HBCD, I can only shake my head again and again. Yesterday, it was conventionally thrown into the incinerator; today everyone screams Jehovah.

Many old and beautiful city villas have half the gable clad with asbestos shingles; if their owners don't turn them into breadcrumbs, nothing happens. Please tell me, what exactly should react in your prefabricated house that hasn't reacted until today?

I asked the question here because there are certainly people who can help me here with their practical experience.

If at all, Will will probably answer; whether the content differs significantly from my answer remains to be seen.

Rhineland greetings

Construction expert: I agree with you on asbestos, but substances like formaldehyde can definitely be present in indoor air. If that is the case, it is certainly not healthy... Something like that should be fairly easy to test, though? The first Google hit for "formaldehyde + test" at least brings up results... And if it only leads to sleeping afterwards without any further worries