KfW-Funding Ventilation Unit – a dialog with Joachim Schrader

When you are in the construction or renovation process of a house and think about the financing of your project, the KfW-funding will cross your path sooner or later. Loans, repayment bonus or investment grants – the range of possibilities is vast. What you need to know and how the KfW-funding works is explained in the following interview with the experienced building energy consultant Joachim Schrader, who is active as a ventilation expert and energy consultant since 2005 and gave advice to countless projects with KfW-funding.

Does it pay off for the builder owner, as for private person or entrepreneur to finance the project with KfW?

J. Schrader: Yes, definitely. Oftentimes it is said that the financing of your project with the KfW is not desirable - does not pay off, too complicated, no visible advantages, too much paperwork; these are the common reasons. But the KfW offers Financing models for highly diverse preconditions – it does not need to be the most energy efficient house, even single measures can enable you to get distinct funding advantages and lucrative repayment bonuses (see graphic). Therefore do not get scared because of the first statements but ask until you understand everything. The most important step is to contact an energy consultant who is listed with the KfW. One more tip: Request references from your energy consultant to get an idea of how experienced they are in advising you with a KfW funding. 

What is the meaning of the different efficiency house standards at the KfW and what specifics have to be taken into consideration for such an application?

J. Schrader: According to the relevant Energy Saving Regulations (EnEV) a reference house is defined by a certain primary energy consumption. This can be called efficiency house 100. The KfW-efficiency house-standard therefore names the difference between the primary energy consumption of the project to the EnEV reference house. Say I have KfW efficiency house 55, what it means is that it only uses 55% of the energy the reference house would need. And this is what determines the possible amount than can be funded with the KfW .
For that matter I recommend to aim at the optimistically highest standard for the application. That is because for the ultimate certification, you can always adjust to a lower efficiency house , for example from KfW 55 to KfW 70, but never from the worse to the better and therefore not from KfW 70 to KfW55. An optimistic planning grants you the highest possible funding rate.
It is also important to know that valid is always the EnEV that has been relevant by the time the building license had been issued. That has to be considered for the data that needs to be entered into the online formula of the KfW.

Is a decentralised ventilation fundable through the KfW?
J. Schrader: Of course. Next to other variations of controlled ventilation, the decentralised ventilation units are fundable as well.  One has to consider the requirements of the EnEV in respect to the ventilating space and the air exchange rate. Besides, this is valid for every system - regardless if it is centralised or decentralised. The calculations of the EnEV function as certification that the building is indeed as energy-efficient as stated and doubles as basis for the respective efficiency house standard. For the efficiency house 40 and 40 Plus, the ventilation system needs to be interpreted according to the nominal ventilation (DIN 1946-6) – which is also useful for the other standards. It is inevitable to name the correct figures for the calculation of the ENEV. This includes the correct manufacturer's data for the ventilation systems as well as the space that needs to be ventilated. If, for example, only 50 % of the living space is efficiently ventilated, the energy efficiency house standard might worsen. This is up to each builder owner's priorities. 

When is the time to submit such an application?

J. Schrader: It is inevitable to submit the application before the respective measures are executed, even before the installers are commissioned. This is by the way also the case for the benefits for the construction-accompanying program (Program 431)!

How are KfW applications granted?

J. Schrader: Your application is submitted by your energy consultant online. He uploads the outcome of the EnEV calculations there, which will be verified through a KfW-program. You will shortly get feedback on whether the application was successful or where need to adjust things. This process is thoroughly electronic and therefore only takes up little time. If the application went through, your energy consultant promptly receives the PDF file that is the affirmation of the application, which he can download.
Next you will need to take this printout to your bank that grants you safety for the KfW. Your local banc consultant can inform you about which safety measures apply between your bank and the KfW. The agency bank then exclusively communicates with the KfW.

What part does the energy consultant play in the further steps of the project?

J. Schrader: For the efficiency house 40 and 40 Plus in newly built houses and the efficiency house 55 for renovations the energy consultant additionally needs to accompany the project, which is optional for other measures. Ultimately, the energy consultant needs to issue a report of the inspection. Additionally to the construction documents, that need to be kept, the report of the energy consultant is crucial for the payout of the funding – this is valid for every funding you want to apply for (find further information here).

How do you as energy consultant advise your customers in respect to the controlled ventilation of living spaces?

J. Schrader: I do automatically create a ventilation concept according to the legal guidelines. This is important to benefit the health of my customers and their tenants as well as to protect the building stock. If the result of the ventilation concept should require an automatic ventilation, I am only willing to accompany the client in their KfW application if they decide to execute this recommendation. A holistic concept for energy saving measures is of essential meaning in order to avoid construction defects and for the future resident live a carefree life in their house.

Thank you very much Mr. Schrader for the insightful interview about your work.

Energy consultant  Joachim Schrader – Life


  • Since 2005: Expert for ventilation and energy consultant of Bauen + Energie
  • 2003 to 2005: Planning and construction manager of the passive housing estate Koblenz-Asterstein.
  • 1999 to 2003: CEO BAUTEAM Rote Schule, Andernach
  • 1990 to 1998: CEO WHS Hochbau, Siegburg


  • 2002 to 2003: Study Building Energy Consultant, University of Kassel
  • 1986 to 1989: IHK Industrial Management Assistant, EHL Beton, Andernach

Comments (0)

No comments found!

Write new comment