Thermal Efficiency Retrofit of Residential Buildings: The German Experience

The report examines the gap between Germany's thermal retrofit targets and current progress, identifying that the retrofit rate for residential outer walls is approximately 0.8% per year against a 2% target. It argues that deep retrofits are most economically viable when integrated into general building renovations. The analysis breaks down the homeowner decision process into three stages—encouraging interest, planning/deciding, and implementation—and maps corresponding policy instruments including information tools, KfW financial incentives, and contractor certification.

• Germany aims to reduce the primary energy demand of buildings by 80% by 2050, with an interim target of a 20% reduction in heat demand by 2020. However, the current annual retrofit rate for residential outer walls is approximately 0.8%, falling short of the government target of 2%.
• Deep thermal retrofits are more economically viable when combined with non-thermal renovations (such as aesthetic improvements) rather than as standalone projects. In such cases, the cost of the thermal component can be reduced to about one-third of the full cost of a standalone thermal retrofit.
• Homeowners' awareness of co-benefits like thermal comfort and lower energy bills is higher among those already planning or implementing retrofits than those who are uninterested. Information channels such as TV and print press are more effective for reaching households in the early, uninterested stage.
• Contractors and public authorities are highly trusted sources of information for homeowners in the planning stage, with 56% of households trusting each. Conversely, while the internet is frequently used, it is not highly trusted due to inconsistent information.
• Financial incentives provided by KfW, including preferential loans and grants, increase in value as the post-retrofit thermal performance improves. However, the low volume of investments under the stricter KfW 55 and KfW 70 standards suggests that marginal increases in financial support (from 14% to 18%) are insufficient to drive most owners toward deeper retrofits.
• The quality of implementation depends on contractor skill, but current education for contractors is deemed insufficient regarding the coordination and communication of deep thermal retrofits. Certification schemes are proposed to incentivize training and increase homeowner trust.

APA

Neuhoff, K., Amecke, H., Novikova, A., & Stelmakh, K. (2011). Thermal Efficiency Retrofit of Residential Buildings: The German Experience. Climate Policy Initiative. https://www.climatepolicyinitiative.org/wp-content/uploads/2011/12/Policies-Supporting-Thermal-Efficiency-in-Germanys-Building-Sector.pdf

Chicago

Neuhoff, Karsten, Hermann Amecke, Aleksandra Novikova, and Kateryna Stelmakh. Thermal Efficiency Retrofit of Residential Buildings: The German Experience. Climate Policy Initiative, 2011. https://www.climatepolicyinitiative.org/wp-content/uploads/2011/12/Policies-Supporting-Thermal-Efficiency-in-Germanys-Building-Sector.pdf.

Wikipedia

{{cite report |last1=Neuhoff |first1=Karsten |last2=Amecke |first2=Hermann |last3=Novikova |first3=Aleksandra |last4=Stelmakh |first4=Kateryna |title=Thermal Efficiency Retrofit of Residential Buildings: The German Experience |publisher=Climate Policy Initiative |date=September 2011 |url=https://www.climatepolicyinitiative.org/wp-content/uploads/2011/12/Policies-Supporting-Thermal-Efficiency-in-Germanys-Building-Sector.pdf |access-date=17 August 2026 |via=Climate Insights Directory}}

BibTeX

@techreport{neuhoff2011thermal, author = {Neuhoff, Karsten and Amecke, Hermann and Novikova, Aleksandra and Stelmakh, Kateryna}, title = {{Thermal Efficiency Retrofit of Residential Buildings: The German Experience}}, institution = {Climate Policy Initiative}, year = {2011}, month = sep, url = {https://www.climatepolicyinitiative.org/wp-content/uploads/2011/12/Policies-Supporting-Thermal-Efficiency-in-Germanys-Building-Sector.pdf}, urldate = {2026-08-17}, note = {Indexed by Climate Insights Directory} }