ᐅ Any experiences with KfW 70 or KfW 55 standards?

Hello fellow home builders,

I’m sure this topic has been discussed here quite often. However, I couldn’t find any entries on it right away, so I’m asking my questions quite specifically. We are currently looking around the market regarding house construction.

It seems that there are four builders we could imagine building a house with.

Now the question is whether we want/should build a KfW70 or a KfW55 house.

Which option would you recommend? Also, considering the upcoming Energy Saving Ordinance 2012 – does anyone already know what it will look like?

Are the additional costs worth it in relation to the energy savings?

One builder, Hanlo Häuser, basically builds KfW70 houses and says that is sufficient. According to them, the additional costs are not offset by the energy savings. The walls at Hanlo have a U-value of 0.13, which is quite good. However, the standard is only double-glazed windows. The standard heating system is an air-source heat pump.

Otherwise, Hanse Haus, Fingerhaus, and Bien-Zenker are still in the running. Their U-values are quite similar, as are the heating systems. Regarding windows, however, they use triple glazing. Is double glazing sufficient?

We are quite unsure about this and would really appreciate some advice.

Thanks and best regards

daugstin

Hello,

daugstin schrieb:
...Which option should we choose? Also considering the upcoming Energy Saving Regulation 2012... Does anyone already know what it will look like? Are the additional costs worth it in relation to the energy savings?

It is undisputed that energy prices (all energy sources) will rise significantly in the future. Looking back, annual price increases have often been well above the general inflation rate. This is likely to continue, as energy for heating and hot water is indispensable.
One slogan says: "The best energy is the energy that is never consumed or needed in the first place."
KfW standards always require higher investments compared to the current Energy Saving Regulation requirements. However, this is mainly from a primary energy perspective! This by no means automatically guarantees economic viability for the builder.
Additionally, it is not uncommon that Energy Saving Regulation or KfW verification calculations have been "beautified," and the expectations of builders regarding the final energy consumption have often not been met in reality. This is mostly due to insufficient efficiency of the building services systems. Frequently, even the primary energy requirements of the verification are not fulfilled.
The new Energy Saving Regulation requirements will further increase investment costs significantly!

daugstin schrieb:
...One builder, Hanlo Houses, generally constructs KfW 70 houses and considers that sufficient. According to their statement, the additional costs are not matched by the savings achieved.

Every general contractor (GC), general developer, or property developer has their own sales and pricing strategy. Naturally, their arguments to potential customers align with this. For example, if 80% of customers, for whatever reasons, request a KfW 70 or Energy Saving Regulation-compliant house, the sales approach will be tailored accordingly. Potential buyers who deviate from this prearranged direction often have poor financial prospects.

daugstin schrieb:
...The walls at Hanlo have a U-value of 0.13, which is quite good. However, the standard windows are only double-glazed. The standard heating is an air-source heat pump.

The U-value of individual components is certainly important, but for an economic evaluation, the overall final energy balance is decisive. For heat generators, combination or compact units are often ordered and installed in large numbers at low cost, even though these tend to be significantly less efficient in practice compared to modular systems.

daugstin schrieb:
...We are unfortunately very uncertain about this and would really appreciate any tips you can give us.

Consulting and reviewing the planned building services systems by an independent expert before signing a contract!

Best regards.

According to the planned Energy Saving Ordinance 2012, the current KfW70 standard will soon be outdated, as will double glazing.

Air source heat pumps only make sense for buildings with efficient building envelopes, typically between KfW55 and the 3-liter house standard.

You might want to consider consulting other developers as well. As far as I know, the current KfW70 standard will soon become the minimum requirement under the Energy Saving Ordinance 2012. You should make sure that the energy performance is not just optimistically calculated, but effective and verifiable. In our case, the desire to meet KfW70, for example, led to having both between-rafter and under-rafter insulation in the roof. Triple-glazed windows are already included with DEURA anyway.

parcus schrieb:
....Air source heat pumps only make sense with efficient building envelopes. So between KfW55 and 3-liter house.

Air source heat pumps do not necessarily require a highly efficient building envelope. What matters are the size of the heating surfaces and the temperature difference of the heating medium in relation to the room heating loads.

Best regards

@€uro

Well, go ahead and install an air source heat pump with its seasonal performance factor in older buildings with inefficient building envelopes, and later explain the point when the meter starts spinning.