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 August 2026 — important: the EBW guideline expires on 31 December 2026; whether and how the programme continues in 2027 is open. Anyone planning a subsidised consultation should apply before the end of the year. The conditions in detail:
- 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
- Application: in the BAFA portal; eligible applicants are owners, homeowner associations, tenants and usufructuaries. The consultation itself may only be carried out by an energy efficiency expert on the dena register.
- Payment: after submission of the report, since April 2025 exclusively to the consulting recipient — direct payment to the energy consultant is no longer possible.
The 5% iSFP bonus
The economic effect 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):
The iSFP bonus raises BEG funding for building-envelope measures by 5 percentage points — since 21 July 2026, however, only from an eligible investment volume of 30,000 EUR and only on the amount above it.
- +5 percentage points of subsidy — since 21 July 2026 only on the part of the eligible costs above the minimum volume (30,000 EUR for one dwelling unit; for multi-family buildings the minimum volume equals the respective cap without an iSFP).
- 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.
- Caps (per calendar year, tiered): without an iSFP 30,000 EUR for the first, 15,000 EUR each for the second to sixth and 8,000 EUR from the seventh dwelling unit; with an iSFP doubled to 60,000 / 30,000 / 15,000 EUR.
Example calculation (illustrative, legal position since 21 July 2026):
| Item | Value |
|---|---|
| WDVS measure, eligible costs | 40,000 EUR |
| Base BEG-EM subsidy (15%) | 6,000 EUR |
| iSFP bonus (+5% on the 10,000 EUR above the 30,000 EUR minimum volume) | 500 EUR |
| Total grant | 6,500 EUR |
The own share remaining after the BAFA grant pays back as soon as a recommended refurbishment step exceeds the minimum volume — for smaller individual measures the roadmap earns its keep through sequencing, no longer through the bonus.
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 an energy planning tool with subsidy access — since the reform of 21 July 2026 with considerably tighter bonus conditions. The own share after the BAFA grant pays back through the bonus on larger refurbishment steps; for smaller ones the value lies in correct sequencing — it prevents costly duplicated work. 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:
- Is an Energy Audit Enough? Why Existing Buildings Need More Than an iSFP
- 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.
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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.