The individual refurbishment roadmap (iSFP – individueller Sanierungsfahrplan) has been the central instrument of nationwide residential energy consulting in Germany since 2017. In 2026 it is not only a consulting document, but also the key to a 5% bonus on subsidies under the federal scheme for efficient buildings (BEG-EM). This article explains the structure, the subsidy logic and the typical pitfalls.
What an iSFP is – and what it is not
The iSFP is a standardised consulting report for a specific residential building. It records the energy as-is state, describes an energy target state (efficiency-house class) and sets out a multi-stage refurbishment path to reach it. Format and content are prescribed by the BAFA guideline and the layout requirements of the German Energy Agency (dena).
An iSFP is not:
- an energy performance certificate (that is a different document with a different purpose and legal basis),
- detailed design of components,
- a heating system quote,
- a subsidy commitment.
Structure of an iSFP report
A complete iSFP typically runs to 30 to 60 pages and follows this structure:
- My house – condition survey: envelope, plant technology, consumption, energy weak points.
- My refurbishment roadmap – the central "roadmap image": one to six refurbishment steps, each with effect on final energy, primary energy, CO2 and with a rough investment estimate.
- My measures in detail – for each step: component description, technical key data (U-values, heating load), subsidy notes, qualitative remarks (mould avoidance, ventilation).
- My economic analysis – cost presentation in a harmonised form, comparison of complete refurbishment vs. step-by-step.
- My subsidies – BAFA and KfW programmes, depending on the step package.
BAFA subsidy logic 2026
Residential building energy consulting is funded under the guideline "Energy Consulting for Residential Buildings (EBW)". As of 2026 (check the current BAFA guideline before applying):
- Grant rate: 50% of eligible consulting costs.
- Maximum amount:
- Single- and two-family houses: up to 650 EUR
- Multi-family houses with three or more units: up to 850 EUR
- Applicant: the energy consultant (listed in the dena-EEE register), not the owner directly.
- Payment: to the owner or directly to the consultant, after submission of the report.
The 5% iSFP bonus
The decisive economic leverage of the iSFP comes after the consultation – when the owner implements one of the recommended refurbishment steps via the federal subsidy for efficient buildings (BEG-EM, individual measures):
- +5 percentage points subsidy uplift on that measure.
- Applicable to: envelope (roof, facade, base slab, windows), plant technology (apart from heating replacement – which has its own bonus), ventilation systems.
- Condition: the measure must be recommended in the iSFP exactly as carried out, and must be implemented within 15 years of iSFP issue.
- Maximum volume: 60,000 EUR eligible costs per dwelling unit and calendar year (BEG-EM cap).
Example calculation (illustrative, as of 2026):
| Item | Value |
|---|---|
| WDVS measure, eligible costs | 40,000 EUR |
| Base BEG-EM subsidy (15%) | 6,000 EUR |
| iSFP bonus (+5%) | 2,000 EUR |
| Total grant | 8,000 EUR |
The iSFP own share of typically 300–500 EUR therefore pays back many times over on the very first subsidised refurbishment step.
The sequencing logic – why it determines economic viability
One of the most important functions of the iSFP is sequencing the refurbishment. Classic mistakes in self-planned refurbishments:
- Heating before insulation: the new heating system is sized for the high heat demand of the uninsulated stock – oversized, inefficient after insulation. Result: a second boiler replacement or permanently poor efficiency.
- Windows before external wall: new airtight windows shift the dew point into the cold external wall – mould risk without accompanying envelope insulation or ventilation concept.
- Attic conversion without an energy concept: thermal bridges at the eaves, incorrectly routed vapour barrier, structural damage after 5–10 years.
An iSFP therefore almost always proceeds in this order: envelope first, then ventilation, then plant technology. Only in justified special cases (a defective heating system as trigger) is this departed from.
Who is authorised to issue an iSFP
Only energy efficiency experts who are entered in the nationwide dena register and who provide annual proof of continuing education are authorised. Architects, engineers, master tradespeople – the listing is open across professions, but tied to a minimum number of training and CPD hours.
In my model for energy consulting in Düsseldorf I take responsibility for on-site data collection, advice and quality control as a chartered architect (AKNW); formal report preparation is carried out in cooperation with listed energy consultant partners. This way both requirements are met: building-engineering depth and formal subsidy eligibility.
Common pitfalls
- iSFP commissioned after the start of works. The iSFP bonus only applies to measures that begin after the consultation. Anyone who has already started refurbishing and then catches up with an iSFP loses the 5% bonus on the ongoing measure.
- Deviating execution. If the executed component differs significantly from the iSFP recommendation (e.g. WDVS 14 cm instead of the recommended 20 cm), the bonus can lapse.
- Loss of the iSFP report. The report must be submitted with the BEG-EM application. No report, no bonus.
- BEG-EM deadline. Submit the application before awarding the contract to the executing company.
Bottom line
The iSFP 2026 is more than a compulsory exercise – it is an economic tool with high leverage. With own shares of just a few hundred euros after BAFA subsidy, it pays back on the first subsidised refurbishment measure. Sequencing is what matters: first the consultation, then the measure – not the other way round. And the quality of the roadmap stands or falls with the building survey – only sound groundwork assessment makes it possible to estimate the costs and risks of the individual steps sensibly.
Related articles:
- What Does Energy Consulting Cost in Düsseldorf?
- GEG 2024/2026: Refurbishment Obligations and Exceptions
- Building Thermography: When It Is Worth It
Next step: Initial discussion for energy consulting and iSFP – free and without obligation.
Next step
Would you like this topic assessed for your property in concrete terms? I offer a free initial consultation — fee ranges, scope and available subsidies discussed openly.