Costs for construction drawings?

So KfW 153 requires energetic specialist planning + construction supervision by an expert for KfW55 certification - see KfW leaflet for details (on the pages of KfW). To be commissioned independently of the construction project! That means the costs should be taken into account. If you need a new building application - you also need to prepare all the documents anew. Effort? And the building application also requires some time and money...

Hello Roger,

Hm ..

That’s how I just felt when I read your answer.

Now we are at this point and I have the following statement from the structural engineer, who is also doing the heat calculation: We are somewhere in the middle between KfW 55 and KfW 70 with the current planning. To achieve KfW 55 I have to do 3 measures:

1. Insulate the floor slab with 5cm more
2. Increase roof insulation above the rafters from 6 to 12 cm
3. Improve windows from 0.9 to 0.7

Insulate below the floor slab? You mean the insulation between the rafters is so far “only” 60 mm?

KfW 55 means a subsidy of 5,000 euros. Now I gathered from the tender documents that 5 cm under the floor slab will cost me about 1,000 euros. The walls from 36 cm to 42 cm cost me about 5,000 euros according to the construction company. The 6 cm thickness of the ceiling insulation is still unknown, but that shouldn’t cost a fortune, right? Now I have extra costs of about 7,500 euros to reach KfW 55, 5,000 will come back from the bank. And I find the 2,500 euros – now just speaking without calculation – okay. There is also a bit more sound insulation, etc.

Not quite right. You have to – regardless of the costs of adding insulation – consider the costs of an amendment from your architect to the building application as well as the costs of an external expert, who is mandatory for KfW 55, otherwise you don’t get the subsidy. The structural engineer who has to recalculate is added on top.

Unfortunately the structural engineer now wants another 1,000 euros to change the plan again .. this just seems a bit much to me, so I’m asking here. I suspect he’s trying to take advantage of my situation that I can only take him for this. That alone would currently prevent me from doing it .. also kind of a gut feeling ..

That is – sorry – the typical statement from an amateur. The structural engineer has to recalculate your building project completely if you want to switch to KfW 55. For this, the thousand euros are a bargain.

Rhenish regards

Hello, just to clarify again: Roof space insulation is 18 or 20 cm between the rafters and according to my architect’s plan, then another continuous layer of 6 cm ABOVE the rafters. I have ultimately also seen this once at a trade fair, you surely know what I mean. The structural engineer / energy consultant wants to increase this layer to 12 cm. My architect also imposed a Swedish panel on me without consultation. According to the specification, it contains 20 cm of insulation, according to the structural engineer he was given the requirement of 15 cm. Another one of the many inconsistencies which I don’t understand ... but the structural engineer / energy consultant said that 20 cm is necessary here. My architect is doing the change order free of charge .. I think he sees it a bit as compensation. It’s still annoying though .. I at least partly already have the energy expert and construction supervision, but I still have to read the contract carefully again. In my eyes it is commissioned .. The structural engineer told me on inquiry, however, that the structural calculations do not have to be redone but only the drawings have to be redone. I was also under the impression that the structural calculations had to be redone, as the house then becomes a bit heavier. But he said that the difference is so little that it can be disregarded. But again the question: Changing the plans in the CAD program, how big is the effort approximately? Does he want to take advantage of my situation or is that realistic? Regards Roger

Hello,

..... My architect also imposed a Swedish panel on me without consultation.....

Was a detailed calculation of the thermal bridges carried out here or was the flat surcharge of 0.05 W/mK used?
In the latter case, I would be interested in the equivalence proof.
The KfW efficiency levels are characterized by two values that must be met. Ht´ for the quality of the building envelope and qp´´ for the primary energy.
If there is a problem with the Ht´ value, improvements are first made to the exterior walls, roof, windows. Floor slabs usually only account for a few percent of the overall balance. Excessive insulation here is often not worthwhile!

Best regards,

NB: I am not a fan of Swedish panels or BKA at all!

That can't be more than 2-3 hours of work on the computer, can it

Hm, I always have to smile at statements like that. With mental work, customers only ever see the time spent. Hardly anyone sees the responsibility behind it....

Regards

1. Insulate the base slab with 5cm more 2. Increase roof insulation above the rafters from 6 to 12cm 3. Improve windows from 0.9 to 0.7

I dare to doubt that these measures alone will get you from KfW 62.5 to KfW 55...... it’s just a gut feeling. And I have a lot of those.