KfW-40 Subsidy: the Process in 7 Steps
From budget planning to verification after completion — with the one rule on which everything depends: The application must be submitted before construction begins.
Application BEFORE construction begins — otherwise the subsidy is lost
The KfW only subsidizes projects that have not yet started at the time of application. Even the conclusion of a construction or supply contract counts as the start. Therefore, sign the contract only after the subsidy approval — not before (Source: kfw.de, Program 297/298, Stand 2026).
The 7 Steps in Detail
- 1
Budget and Subsidy Check
Clarify total costs, equity capital and possible programs (KFN 297/298, WEF 300, state and municipal subsidy). This way you know early which subsidy framework is realistic.
- 2
Involve energy efficiency experts
Commission a listed expert from the energy efficiency expert list. The expert plans the EH40 verification and later prepares the confirmation for the application (BzA).
- 3
Select provider — with EH40 commitment
Compare offers and select a provider that contractually guarantees the Efficiency House 40 standard. No signature yet — the contract waits for the subsidy approval.
- 4
Have the BzA prepared
The energy efficiency expert prepares the confirmation for the application (BzA). It is the prerequisite for the KfW application and confirms that the project will achieve the EH40 standard.
- 5
Application via house bank/financing partner
The KfW subsidy is applied for via your bank, savings bank or an intermediary — never directly with the KfW. The partner submits the application including the BzA.
- 6
Wait for approval — then contract & construction start
Only after receipt of the subsidy approval may the construction contract be signed and construction begun. Acting prior to this leads to rejection of the application.
- 7
Verification (BnD) after completion
After construction is completed the expert provides the confirmation after implementation (BnD). It verifies the achieved standard and is a prerequisite for the final subsidy disbursement.
In-depth on the individual steps
Which technical limit values your house must meet in the step "EH40 commitment", read under EH40 Requirements. The tasks of the expert in step 2 and 4 are explained on the page Energy Efficiency Expert & Verification. Which programs you should check in step 1 is shown in the overview of the Subsidy Programs. Depending on the situation up to 270.000 € low-interest subsidy loan is possible via KFN (297/298) and WEF 300 (Stand 2026, range depending on QNG and number of children).
The typical pitfalls and what they cost have been compiled separately under The Most Expensive Subsidy Mistakes compiled. How several subsidy sources can be sensibly combined is described under Combining Subsidies. The current conditions of the KfW.
Frequently Asked Questions on the Subsidy Process
Answers on application timing, financing partner, expert and verification (Stand 2026).
Why must the subsidy application be submitted before construction begins?
Do I apply for the KfW subsidy directly with the KfW?
When do I need the energy efficiency expert?
How long does it take until subsidy approval?
Can I already plan and obtain offers before the approval?
What happens if the house narrowly misses the EH40 requirement in the end?
Start with step 1: Clarify budget and subsidy
Request offers from eligible providers and establish the basis for a smooth application — free of charge and without obligation.
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