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24.9.2025

The 2025 Funding Guide: Which roof extension funding should you recommend to your customers?

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Table of contents

The 2025 Funding Guide: Which roof extension funding should you recommend to your customers?

As a roofer, carpentry or PV installer, this gives you a complete overview of all available funding programs for roof construction 2025, with specific funding amounts, precise technical requirements and practice-oriented recommendations for your customer advice — so that you can recommend the optimal funding for every project.

2025 funding landscape at a glance: BAFA, KfW and regional programs

BEG funding 2025 is based on three pillars: BAFA subsidies for individual measures (15—20%), KfW loans with repayment subsidy for complete renovations (up to 31%) and tax support (20% over three years). States and municipalities offer additional programs, which can often be combined.

BAFA BEG EM: 15-20% subsidy for individual energy measures

The BAFA program “Federal Funding for Efficient Buildings — Individual Measures” (BEG EM) is the first choice for most roofing projects. The basic funding amounts to 15% of the eligible costs, with an additional 5% bonus when using an individual restructuring schedule (ISfP).

Funding conditions in detail:

Maximum eligible costs: €30,000 without ISfP, €60,000 with ISfP per residential unit
Maximum funding amount: €12,000 per residential unit with 20% funding
Minimum investment: €300 gross for the application
Energy efficiency expert: Mandatory inclusion for application and proof of use

For a typical roof renovation project, this means: With a 120m² roof area with a cost of €150/m² (€18,000 total costs), there is BAFA funding of €2,700 (15% basic funding) to €3,600 (20% with ISFP bonus).

KfW programs: Loans with repayment subsidy for efficiency house renovations

In 2025, KfW offers three relevant programs for roof renovation: KfW 261 for efficiency house renovations with up to 31% repayment subsidy (maximum €37,500) and the KfW 358/359 supplementary loans with up to €120,000 credit volume with interest reductions for households with an annual income of less than €90,000.

KfW 261 - Efficiency house renovation:

Credit volume: up to €150,000 per residential unit
Repayment subsidy: up to 31% (maximum €37,500) depending on the efficiency house standard achieved
Interest rate: 1.81-2.63% effective (as of September 2025)

KfW programs are suitable for comprehensive roof renovations as part of an overall building renovation, as they offer different financing conditions and technical requirements than individual BAFA measures.

Customer advice: funding recommendations by project type

Roof insulation with new covering: optimal BAFA funding

BAFA funding is usually the best recommendation for classic roof renovation with insulation and new covering. The program covers both insulation measures and accompanying work such as airtightness and vapor control, provided that the minimum technical requirements are met.

Practical tip for customer advice:

For individual measures below €30,000: recommend BAFA BEG EM
For costs above €30,000: Use the ISFP bonus for double eligible costs
Recommend tax bonus only to customers without other federal funding

For 120m² roof renovation with €150/m², there are the following funding options: BAFA 15% = €2,700, BAFA 20% (with ISfP) = €3,600, or tax bonus 20% = €3,600 spread over three years.

PV integration: Combined funding strategies for solar roof projects

Roof renovation with PV installation opens up combination options that are particularly attractive for your customers. BAFA funding for the building envelope (roof insulation) can be combined with other funding programs for the PV system.

Make optimal use of the funding combination:

BAFA BEG EM for roof insulation (15-20%)
KfW 270 for PV system (low-interest loan)
Regional PV funding is also possible (e.g. Hanover: €50/m² for a roof-solar combination)

In Baden-Württemberg, there is a PV installation requirement within two years for major roof renovations — an important advisory aspect for your customers in this federal state (as of current state building regulations).

Complete restructuring: KfW 261 with up to 31% funding

KfW 261 will be the first choice for comprehensive renovation projects involving roof, façade and building technology. Funding increases with the efficiency house standard achieved: 20% for EH 85, 25% for EH 70, and 31% for EH 55.

The same 120m² roof project as part of an efficiency house renovation results in the following funding amounts: EH 85 = €3,600 (20%), EH 70 = €4,500 (25%), EH 55 = €5,580 (31%).

Application process and timing: What tradesmen need to know

Before awarding a contract: funding application and involvement of energy consultants

Since 2024, the application process has changed: You can already conclude a contract with your customer, but must incorporate resolving conditions in the event of a funding rejection. The funding application must be submitted before work starts.

The 5-step process:

Energy efficiency expert prepares technical project description (TPB)
Conclude a contract with resolving conditions
Customer submits funding application with TPB
When approved: Start work
After completion: Technical project proof (TPN) and proof of use

The work must be completed within 36 months of approval; extension of 12 months is possible. 50% of energy consulting costs are subsidized (max. €2,500 for single-family homes).

Minimum technical requirements for roof insulation

The technical requirements for funding are significantly stricter than the minimum legal standards. While the GEG requires a U-value of 0.24 W/ (m²·K) for renovations, funding programs require 0.14 W/ (m²·K) for pitched roofs.

DIN-compliant minimum requirements:

Pitched roofs: U value ≤ 0.14 W/ (m²·K) (vs. GEG: 0.24 W/ (m²·K))
flat roofs: U value ≤ 0.20 W/ (m²·K)
In case of technical restrictions: maximum insulation thickness with λ ≤ 0.035 W/ (m·K)

In practice, this means that mineral wool with λ = 0.035 W/ (m·K) requires at least 25-30 cm insulation thickness for the conveying U-value of 0.14 W/ (m²·K).

3D roof measurement for precise funding applications: With DIN-compliant Airteam measurements You will receive exact roof data for your funding applications in 24 hours — without a ladder, with centimeter precision for correct U-value calculations.

Funding amounts and project calculations 2025

The specific funding amounts vary considerably depending on the size of the project and the selected program. Here are the most important calculation bases for preparing your offer:

Sample project 120m² pitched roof (€18,000 total costs):

BAFA 15%: €2,700 funding
BAFA 20% (with ISfP): €3,600 funding
20% tax bonus: €3,600 over three years (7%-7% -6%)
KfW EH 85 (20%): €3,600 funding
KfW EH 55 (31%): €5,580 funding

Sample project 80m² flat roof with PV preparation (€14,000 total costs):

BAFA roof insulation 20%: €2,800
Regional PV funding: ~€2,400 (80m² × €30/m²)
Total funding: up to €5,200

The choice of funding program should be based on processing time, documentation costs and specific customer goals — BAFA for individual measures, KfW for comprehensive restructuring.

Additional regional funding: making optimal use of local pots

In addition to federal programs, many states and municipalities offer additional funding, some of which can be combined. The programs vary widely regionally and change frequently due to limited budgets.

Current regional highlights 2025:

Hanover (ProKlima): €100/kWp for full PV occupancy + up to €9,000 additional bonuses
NRW: Progres.NRW restart planned with €60M budget until 2028
Berlin: SolarPlus program available again since March 2025

As a rule of thumb, you can expect €30/m² additional funding for regional programs, i.e. around €3,600 additional for a 120m² roof — but the fluctuation range is ± 50% depending on the region and program availability.

Practical tip: Before making any offer, check the current regional programs in your project region, as these are often paused or relaunched at short notice.

Frequently asked questions (FAQ)

Which funding is best for my roof project?

For individual measures up to €30,000, BAFA BEG EM is ideal (15-20% subsidy). For total renovations of over €50,000, KfW 261 can become more interesting with a repayment subsidy of up to 31%.

Can I combine BAFA funding with regional programs?

Yes, BAFA funding for building envelopes can generally be combined with regional PV or special programs, as long as they support various measures.

How long does it take to process funding applications?

BAFA applications: 6-8 weeks; KfW applications: 8-12 weeks. Plan appropriate lead times into your project planning.

What happens if the funding application is rejected?

With resolving conditions in the contract, both you and the customer can withdraw from the order at no cost.

Make optimal use of funding: With precise DIN-compliant Airteam roof measurements Create 90% faster offers and reduce production risks through accurate quantity and U-value calculations. Your customers benefit from maximum funding utilization with minimal supplements.