Drivers of Thermal Retrofit Decisions – A Survey of German Single- and Two-Family Houses

The report analyzes a survey of 2,000 German homeowners, categorizing them into non-planning, planning, and action households. It finds that motivations shift during the process, with building appearance being a primary initial trigger, while thermal comfort and energy savings become more important for those who have already implemented retrofits. High up-front costs and reluctance to take loans are major barriers, and the study highlights the critical role of the Internet, construction professionals, and personal networks as information sources. Financial support, specifically through KfW programmes, is shown to increase the likelihood of comprehensive retrofits and reduce the tendency to drop planned measures.

• Motivations for thermal retrofits evolve as homeowners progress through the decision-making process. Building appearance is a primary trigger across all stages, but thermal comfort and reduced energy bills become significantly more important for households that have already implemented retrofits.
• Financial constraints and perceived complexity are the primary barriers to retrofitting. Homeowners are particularly concerned about high up-front costs, a reluctance to acquire loans, and the time and effort required to research and evaluate options.
• Homeowners frequently modify their retrofit plans, typically by removing components. Between 75% and 90% of those who change their plans do so because of the costs associated with specific measures.
• Information sources vary by stage: the Internet and construction professionals are key throughout, while mass media is effective for initial awareness but less useful for those in the action stage. Personal communications, such as forums and neighborhood associations, also play a significant role.
• Investment payback is the most significant financial motivator and increases in importance as households move toward implementation. The use of KfW programmes is associated with a higher likelihood of completing comprehensive retrofits and a lower tendency to drop planned energy efficiency options.

APA

Novikova, A., Vieider, F., Neuhoff, K., & Amecke, H. (2011). Drivers of Thermal Retrofit Decisions – A Survey of German Single- and Two-Family Houses. Climate Policy Initiative. https://www.climatepolicyinitiative.org/wp-content/uploads/2011/12/Drivers-of-Thermal-Retrofit-Decisions-A-Survey.pdf

Chicago

Novikova, Aleksandra, Ferdinand Vieider, Karsten Neuhoff, and Hermann Amecke. Drivers of Thermal Retrofit Decisions – A Survey of German Single- and Two-Family Houses. Climate Policy Initiative, 2011. https://www.climatepolicyinitiative.org/wp-content/uploads/2011/12/Drivers-of-Thermal-Retrofit-Decisions-A-Survey.pdf.

Wikipedia

{{cite report |last1=Novikova |first1=Aleksandra |last2=Vieider |first2=Ferdinand |last3=Neuhoff |first3=Karsten |last4=Amecke |first4=Hermann |title=Drivers of Thermal Retrofit Decisions – A Survey of German Single- and Two-Family Houses |publisher=Climate Policy Initiative |date=July 2011 |url=https://www.climatepolicyinitiative.org/wp-content/uploads/2011/12/Drivers-of-Thermal-Retrofit-Decisions-A-Survey.pdf |access-date=17 August 2026 |via=Climate Insights Directory}}

BibTeX

@techreport{novikova2011drivers, author = {Novikova, Aleksandra and Vieider, Ferdinand and Neuhoff, Karsten and Amecke, Hermann}, title = {{Drivers of Thermal Retrofit Decisions – A Survey of German Single- and Two-Family Houses}}, institution = {Climate Policy Initiative}, year = {2011}, month = jul, url = {https://www.climatepolicyinitiative.org/wp-content/uploads/2011/12/Drivers-of-Thermal-Retrofit-Decisions-A-Survey.pdf}, urldate = {2026-08-17}, note = {Indexed by Climate Insights Directory} }