KfW Efficiency House 70 (153) requirement?

Hello everyone here in the forum,

how is it actually. What are the requirements for a house to achieve [Kfw70]? I have already read a little about [KfW], but I haven’t really understood what [Kfw70] requires.

Can someone help me here?

Hello,

What exactly does a house need to have to achieve KFW70??

KfW Efficiency House 70

KfW Efficiency House 70 (formerly KfW 60) refers to houses with a minimum energy efficiency. This is based on the Energy Saving Ordinance (Energieeinsparverordnung), which sets the criteria for the modern, efficient building standard (KFW 100). The KfW 70 efficiency house is only allowed to consume 70% of the energy compared to that standard. This categorization also affects subsidies provided by the KfW. This is where the name KfW Efficiency House 70 comes from.

Definition KfW Efficiency House 70

Compared to the house type KfW 55 (formerly KfW 40), the subsidy criteria for KfW Efficiency House 70 (formerly KfW 60) are less strict. Because the improvements compared to the standard KfW 100 (low-energy house) according to the Energy Saving Ordinance are smaller as well:

· Annual primary energy demand Qp and transmission heat loss HT´ maximum 70% of the values allowed according to Energy Saving Ordinance 2007 and
· Annual primary energy demand maximum 60 kWh per m2 of usable building area AN

How is KfW 70 achieved?

Windows and doors insulate almost as well as the exterior walls. Buildings with oil or gas condensing boilers or heat pumps, built with ETICS (externally insulated composite systems), generally require a central ventilation system with heat recovery.
Depending on which masonry and thickness (e.g., 36.5 cm) are installed, a ventilation system can be omitted. However, the technology must be upgraded accordingly to meet the annual primary energy demand; for example, with a geothermal or air/water heat pump.

Subsidies for KfW Efficiency House 70

The KfW (Kreditanstalt für Wiederaufbau) promotes the purchase or construction of energy-saving houses with low-interest loans. One house type is called KfW Efficiency House 70 (formerly KfW 60). The KfW subsidy program is called “Ecological Building” and provides loans up to an amount of €50,000.00.

Kind regards

Planned is a condensing boiler with solar underfloor heating, triple glazing, and 42cm masonry; is a ventilation system still needed for this or can it be omitted

I would fundamentally recommend that to you... You will not really and even remotely ventilate the house as well as the controlled residential ventilation system will do. Regardless of whether it is a central or decentralized system.

The ventilation heat lost (irretrievably) through proper shock ventilation / cross ventilation, if done properly, cannot be immediately replenished. The heating capacity corresponding to the house is no longer able to do so! Anyone planning to build should keep this in mind clearly!

Hello,

....is a ventilation system still needed for this or can it be dispensed with

Ventilation systems are primarily comfortable! Comfort means CoSten approx. 5...10 k€ for a single-family house!
They are not mandatory, but sometimes necessary and indispensable!
You can get professional and independent advice on this. The cost of advice is not comparable to the system and operating costs.

Best regards.

I would like to join in and additionally ask:

How much final energy demand (not primary energy demand!) is to be expected for a KfW Efficiency House 70 per m²a? For the KfW 60 house, it was 60 (primary energy), which then automatically corresponds to 60 final energy with a gas heating system. But since the calculation basis was somehow changed, no one really understands it anymore...

Does anyone have experience? An order of magnitude of +/- 5 kWh/m²a would be sufficient for me. (BTW: is that the actual m² or a fictitious m² according to the reference building stuff...)?

Thanks