Tax Incentives for Thermal Retrofits in Germany: Experiences from Practitioners

This report by the Climate Policy Initiative and DIW Berlin presents findings from a survey of 78 thermal retrofitting practitioners to inform the German government's debate on tax incentives for residential building retrofits. The study evaluates the effectiveness of comprehensive versus single-measure retrofits, the appropriateness of the KfW 85 energy standard, the necessary timeframes for project completion, and the risks associated with stepwise implementation.

• A strong majority of practitioners favor comprehensive thermal retrofits over single measures for long-term benefits. Specifically, 70% of practitioners recommended comprehensive retrofits, with experts citing them as the superior option for energy savings (85%), coordination of measures (90%), and post-retrofit comfort (95%). Conversely, single measures are viewed as more manageable in the short term regarding financing and comfort during construction.
• Practitioners generally view the KfW 85 standard as a practicable target for comprehensive retrofits, even without additional tax incentives. Survey results show that 25% of practitioners recommended standards higher than KfW 85, 15% recommended KfW 85, and 30% recommended KfW 100 or 115. Fewer than 5% recommended the legal minimum standard.
• The proposed 10-year flexibility period for completing retrofits is considered unnecessary by practitioners. While 55% believe extending the existing 36-month KfW flexibility period would encourage deeper retrofits, the vast majority (96%) believe an optimal period would be less than 61 months, with an average recommendation of 50 months.
• Stepwise retrofits carry significant risks if not executed in a specific sequence, potentially leading to structural damage and financial loss. 95% of practitioners stated that a specific sequence is required to avoid such issues. Failure to follow the correct order—prioritizing the building envelope (roof first) before heating systems—can increase the probability of mold by at least 25% for 80% of practitioners, reduce energy savings by 15%, and increase total costs.
• To mitigate the risks of stepwise retrofits and prevent state and homeowner losses, the report suggests making an energy audit a prerequisite for tax incentives. This is based on the finding that uncoordinated retrofits, such as installing heating systems before the building envelope, lead to oversized systems, higher costs, and energy losses.

APA

Amecke, H., Neuhoff, K., & Stelmakh, K. (2012). Tax Incentives for Thermal Retrofits in Germany: Experiences from Practitioners. Climate Policy Initiative. https://www.climatepolicyinitiative.org/wp-content/uploads/2012/01/Tax-Incentives-for-Thermal-Retrofits-English-language.pdf

Chicago

Amecke, Hermann, Karsten Neuhoff, and Kateryna Stelmakh. Tax Incentives for Thermal Retrofits in Germany: Experiences from Practitioners. Climate Policy Initiative, 2012. https://www.climatepolicyinitiative.org/wp-content/uploads/2012/01/Tax-Incentives-for-Thermal-Retrofits-English-language.pdf.

Wikipedia

{{cite report |last1=Amecke |first1=Hermann |last2=Neuhoff |first2=Karsten |last3=Stelmakh |first3=Kateryna |title=Tax Incentives for Thermal Retrofits in Germany: Experiences from Practitioners |publisher=Climate Policy Initiative |date=18 January 2012 |url=https://www.climatepolicyinitiative.org/wp-content/uploads/2012/01/Tax-Incentives-for-Thermal-Retrofits-English-language.pdf |access-date=17 August 2026 |via=Climate Insights Directory}}

BibTeX

@techreport{amecke2012tax, author = {Amecke, Hermann and Neuhoff, Karsten and Stelmakh, Kateryna}, title = {{Tax Incentives for Thermal Retrofits in Germany: Experiences from Practitioners}}, institution = {Climate Policy Initiative}, year = {2012}, month = jan, url = {https://www.climatepolicyinitiative.org/wp-content/uploads/2012/01/Tax-Incentives-for-Thermal-Retrofits-English-language.pdf}, urldate = {2026-08-17}, note = {Indexed by Climate Insights Directory} }