KfW loan 358/359 via your bank

As of 2026 — terms and income thresholds can change; verify with your bank/KfW.

Alongside the grant there's a low-interest supplementary loan (Ergänzungskredit) to finance your share. Importantly, it's applied for not directly with KfW but through your house bank.

358 vs 359 — the difference

• KfW 358: the income-dependent variant — below a household-income threshold (order of magnitude ~€90,000 taxable income) there's a particularly favourable interest rate.
• KfW 359: the standard variant without an income limit.

Both go up to €120,000 per residential unit and complement the grant (they finance the part the grant doesn't cover).

How it fits the sequence

The loan requires the funding approval. So: first BzA → application → KfW approval, then with that approval to your house bank. The bank passes the KfW loan through ("Durchleitung").

Practical tip: you can prepare the bank conversation in parallel before the approval arrives — then it's faster once it does. Ask early what documents the bank needs.

What the bank checks

• Creditworthiness / income proof, possibly a land-register extract (as with other loans).
• For §358, the income threshold (decides whether you get the cheaper rate).
• Whether it brokers the KfW loan at all — not every bank actively does the pass-through. If your house bank is reluctant, you can use another pass-through bank.

If KfW doesn't fit

If the supplementary loan doesn't cover everything (or you want to finance more), ask the bank about alternative loans — often the rest can be a regular loan or folded into an existing mortgage. Get the interest rate, term and conditions.

In short: 358 = income-dependent/cheaper, 359 = no income limit, both up to €120,000/unit, via your house bank after the KfW approval. Prepare the bank talk in parallel; not every bank actively passes through.

On to the layer below: stacking municipal grants.