Choose the measure and applicant before the percentage
For private residential heating replacement, start with KfW 458. For relevant envelope measures such as insulation and windows, read the BAFA envelope programme. Other programmes have their own routes; a heating checklist is not a universal application process for all renovation.
Record property type, owner/applicant, intended occupation, exact measure and previous funding. In a WEG, establish whether common or private property is affected and who is authorised to apply. Confirm the technical requirements with the appropriate specialist. Eligible expenditure can be smaller than the actual bill and may have limits that depend on the building and application date.
Follow the current contract and application sequence
| Stage | BAFA envelope measure | KfW 458 heating |
|---|---|---|
| Technical preparation | Required energy-efficiency expert; TPB/project description | Expert or qualifying specialist business; BzA |
| Contract before application | Required supply/service contract with grant condition and expected date | Required contract with KfW condition and expected date |
| Application | BAFA portal with applicable TPB-ID | Meine KfW with BzA and required documents |
| Execution | Check receipt, decision and conditions; early start after application is at own risk | Plan execution after commitment under current product conditions |
| Completion/payment evidence | TPN, invoices and required non-cash payment evidence | BnD, invoices and product-specific evidence |
| Payout | After positive evidence review | After positive evidence review |
The current BAFA process requires a contract whose validity depends on the funding decision. Applying is not the same as receiving approval; BAFA explicitly warns that starting after application but before the decision is at your own risk. For KfW, the current458 leaflet treats an unconditional contract or work started before application as a harmful project start. Do not sign unconditionally and assume a clause can simply be added afterwards.
Check the July 2026 changes and the actual leaflet
The current BAFA leaflet, version1.13 effective 21 July 2026 changes the iSFP bonus calculation. For the stated one-dwelling case, the minimum eligible investment is EUR 30,000 in the relevant application; the extra five percentage points apply only to the amount above that threshold. Separate smaller applications are not simply added together to reach it. Different dwelling counts and conditions need their own check.
For a deliberately simplified eligible EUR 40,000 envelope measure, assuming all applicable conditions and the 15% base rate, base support is EUR 6,000. The extra 5% applies to EUR 10,000, giving EUR 500; total EUR 6,500, rather than EUR 8,000 obtained by applying 20% to everything. This is an illustration of the checked rule, not an individual grant decision. Confirm eligible lines, limits and iSFP status before using it.
Keep full cost and cash needs visible
| Item | Amount |
|---|---|
| Defined works assumed eligible | 40 000 |
| Other works not claimed here | 6 000 |
| Planning not claimed here | 2 000 |
| Chosen reserve | 4 000 |
| Full available funding before payout | 52 000 |
| Illustrative grant if fully approved and evidenced | 6 500 |
| Owner cost after that grant | 45 500 |
| Own funds available before payout | 47 000 |
| Temporary funding gap including reserve | 5 000 |
EUR 47,000 is enough for the model’s eventual owner cost but not for the full EUR 52,000 availability before payout. If an actual grant were only EUR 5,500, eventual owner cost would be EUR 46,500. Cash timing still needs checking against each due invoice; a smaller eventual cost is not money already in the account.
Allow for proof, delays and finance costs
KfW currently warns that evidence submission for affected self-occupying owners applying under the new income-bonus conditions is expected from January 2027. Check the live product notice for your case before promising a reimbursement month. This notice does not mean every KfW applicant has the same delay. Keep submission and completion deadlines from the actual commitment.
Retain the applicable leaflet, accepted conditional contract, technical IDs, commitment, approved changes, invoices and traceable transfers. BAFA’s evidence guidance requires project attribution and non-cash payment. Do not claim the same measure twice with KfW and BAFA or add incompatible tax relief; combinations need their own programme check.
A EUR 5,000 bridge loan is finance, not an additional EUR 5,000 construction expense. If the fictional bridge costs EUR 150 interest and EUR 50 fees, add EUR 200: funding including finance becomes EUR 52,200 and owner cost after the assumed EUR 6,500 grant is EUR 45,700. Loan repayment and the grant must each be represented once.
Keep support as a controlled scenario
- Check the correct current programme and applicant.
- Confirm specialist involvement and eligible scope.
- Arrange the required conditional contract and application timing.
- Keep decision, expiry and proof deadlines.
- Finance the full cash need until reimbursement.
- Update the scenario only when documented facts change.
Reno Pro can organise work, invoices and recorded payments. Keep a separate funding worksheet or project note for the application and expected grant; the app does not issue technical confirmations or submit the application. A sound renovation decision still works as a cash plan while support is pending.
Sources, date and scope
- BAFA — Einzelmaßnahmen an der Gebäudehülle
- BAFA — Informationen zur Antragstellung — aktueller Ablauf
- BAFA — Allgemeines Merkblatt zur Antragstellung — Juli 2026
- KfW — Heizungsförderung für Privatpersonen — Wohngebäude (458)
- KfW — Merkblatt 458 — Stand 09/2026
Checked on 19 October 2026. Local examples concern Berlin unless stated otherwise. Check state law, heritage protection, community rules and actual work for the specific project. Teaching figures are invented euro amounts, not market prices or offers. The article projects are independent. Tax and funding calculations apply only under the stated assumptions; competent professionals resolve project-specific technical and legal questions.