KFW - fulfilled by which measures?

Hi,

which construction measures have you implemented to achieve KFW55 and thus the funding?

Specifically, I am interested in:
- Which heating system
- Which brick for solid construction
- Ventilation system with heat recovery (yes/no?)
- Insulation value of the windows

Thanks!

Hello,

which structural measures have you implemented to achieve KFW55 and thus the funding?

Specifically, I am interested in:
- Which heating system
- Which bricks for solid construction
- Ventilation system with heat recovery (yes/no?)
- Insulation value of the windows

Thanks!

- Optimized construction without projections, bay windows, dormers, etc. Simply rectangular
- small windows on the north side
- almost no windows on the east side
- many & large windows on the south side
- large windows on the west side
- air-water heat pump
- hollow brick T8 36.5 cm unfilled
- roof insulation 24 cm Styrodur
- basement floor insulation 8 cm Styrodur
- triple-glazed windows & doors with warm edge
- basement with 12 cm perimeter insulation
- ventilation system with heat recovery
- individual verification of thermal bridges
- blower door test

Addon:
- photovoltaic system 8.82 kWp
- fireplace

With this, I am exactly 0.001 below the reference value.

The U-value and the energy value are two completely different things. The ventilation system does not compensate for a poor U-value. If the insulation of the building envelope is poor, then you will not achieve the reference value even if you fill your house with technology.

In my case, I only barely achieve KfW55 even though the technology exceeds the requirement threefold.

Optimized design without projections, bay windows, dormers, etc. Simply rectangular

Does it make that much of a difference? Because we have a bay window and the front door between the house and garage.

I understand windows facing true north, but would windows facing east be negative?

For the rest, we are basically on the same page as you. I would just like to save all the effort if it’s clear that we won’t get there anyway or would have to invest something extra.

What does saving effort mean? Whether you achieve KfW55 can only be told to you by your energy consultant! If you do not achieve it with the means described above, then something has to be improved somewhere. Possibly 42.5 cm bricks, better insulation of the basement floor, even better windows, etc.

What does saving effort mean? Only your energy consultant can tell you if you can achieve KfW55!

Exactly that effort. As far as we know, our architect said it is only necessary if you want to sell a house or if you have something to do with KfW?

Exactly this effort. As far as our architect told us, it is only necessary if you want to sell a house or if it has something to do with KfW?

You have to achieve certain measurement values so that your house reaches KfW55 and you get the corresponding funds. It is a simple cost-benefit calculation of what the additional effort brings you (energy saving or cheap loan).

It's like buying a Tesla, you have a nice electric vehicle for €90,000. cheap in consumption, expensive in purchase.