Insulating prefabricated house with additional insulation, DIY, inexpensive styrofoam

Hello everyone,

my prefab house provider offers me a standard low-energy house Kfw70.
I have now received the price if we take an insulation package KFW 55, and have found that only the insulation in the roof and upper floor changes here. Exterior walls are already basically in the Kfw 55 standard and are not further reinforced with this package. Cost of the package about 6000 euros

The question to the experts now is, can I also take the standard package and simply add additional insulation in the attic through self-labor?
For example, just laying everything out with Styrofoam in the attic as no one really goes up there anyway.
How do you assess this measure?

Thanks and best regards

Hello,

my prefabricated house provider offers me a low-energy house KfW70 as standard.

Which provider is it? It is strange that he does not already offer you KfW 55 as standard? This branch of providers can still score points with it, and therefore it does not make sense to me that yours omits it?

The question to the experts is now, can I also take the standard package and simply add additional insulation in the attic by myself?

Sigh ... you can do a lot if you have the craftsmanship. If you need proof that it is actually a KfW 55 efficiency house, the situation looks quite different in my opinion.

What kind of technology is being offered?

Kind regards from on the road

Hi. The provider is Bien-Zenker. Bien-Zenker offers an air heat pump technology which I want to support in winter with a 7kW stove running on wood. I have also already spoken with several families using this technology; all were satisfied. Therefore, the question is whether it would not be better to insulate more in order to achieve a better value (kW per m²). I am specifically concerned about ceilings and the roof.

Hello,

Provider is Bien-Zenker.

I am currently waiting for the documents from my clients – I hope they will be available after my return. Therefore, I cannot say much about the provider itself or its services.

As technology, he offers an air heat pump which I want to support in winter with a 7 kW stove running on wood. I have also already spoken with several families who use this technology, all were satisfied. Therefore, the question is whether it is not better to insulate more in order to achieve a better value (kW per m²). I am specifically concerned about ceilings and roof.

7 kW is quite something – I also assume you mean an air-to-water heat pump?

If you have already spoken with the provider’s customers anyway, why didn’t you ask them what they think of your idea, or whether they have upgraded to kfW 55? You should get information from first hand here, right?

Best regards from the road

Hello,


I am currently waiting for the documents from my clients - I hope they will be available when I return. Therefore, I can't say much about the provider itself or their services.


7 kW is quite significant - I also assume that you mean an air-to-water heat pump?

If you have already spoken with the clients of the provider, why didn't you ask them what they think about your idea, or whether they upgraded to kfW 55? You should be able to get information firsthand here?

Best regards from the road

They said that they insulated with kfW 40 but using 2007 standards so to speak. Since I cannot compare that, my idea was to go for kfW 70 and then insulate the roof additionally.
Tell me, do you have experience with air-to-air heat pumps in combination with wood stoves?
Do you also have experience regarding soundproofing with providers like Bien-Zenker compared to solid houses?

Hello,

my prefabricated house provider offers me a standard low-energy house kfw70.
I have now received the price if we take a KfW 55 insulation package, and have noticed that only the insulation in the roof and upper floor changes here.

The two standards differ in the Qp´´ value. So not only by the Ht´ value (insulation).

...The question to the experts now is, can I also take the standard package and simply add insulation in the attic by myself? e.g. just lay everything out with Styrofoam in the attic since nobody walks on the roof anyway.

Unfortunately, it’s not that simple if it is actually sufficient; a professional execution is required (among other things, airtightness, dew point issues, etc..[/quote] So just throwing in a few insulation boards is not an option!
For the additional €6k, one could also stay with KfW 70 and instead of the air heat pump choose a brine heat pump with various different, inexpensive sources. This can still leave some investment with simultaneously lower consumption ;-)
But without sufficient basic investigation, no precise statements!
It does not always make sense to blindly chase a subsidy.

Best regards