ᐅ New Construction KfW 70 House and Your Feedback on Our Project

Hello,

We are currently planning a new build for our family.
The plan is for a bungalow with an attic space for storage (wood-beam ceiling).
This week, the energy consultant came and presented the calculation for the planned KfW 70 house.

I will upload the documents from the energy consultant later or add them to this thread.

One of my first questions was how to improve from KfW 70 to KfW 55 and what the cost implications would be.

Now I would like to hear your opinions on the documents and then ask my questions.

So far, these are the facts:

- Single-layer wall construction 36.5 cm (14.4 inches) Bisotherm Bisoplan 0.09
- Air-to-water heat pump
- Underfloor heating
- No mechanical ventilation with heat recovery
- 5 cm (2 inches) insulation below and 8 cm (3 inches) insulation above the foundation slab

These are my questions:
- Are the additional costs for a Bisotherm block with integrated insulation worthwhile or wasted money?
- Should I rather increase the insulation in other areas such as below and above the foundation slab or in the ceiling?
- ..........