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

This report by the Climate Policy Initiative analyzes the decision-making process of 2,000 German owners of single- and two-family houses regarding thermal efficiency retrofits. The study categorizes households into non-planning, planning, and action stages to identify how motivations, financial barriers, and information sources evolve throughout the process. Key findings highlight that while building appearance is a primary initial trigger, financial concerns and the desire for thermal comfort and energy savings become more prominent as households move toward implementation.

• The motivations for pursuing thermal retrofits evolve as homeowners progress through the decision-making process. Building appearance is the primary trigger for those not yet planning or just starting to plan, while thermal comfort, high energy bills, and structural redesign become more significant for those who have already implemented retrofits.
• Financial constraints are a major barrier to thermal retrofits, specifically high up-front costs and a reluctance to take on loans. Between 75% and 90% of households that modify their plans by dropping components do so because of high costs.
• The perception of the retrofit process is consistently negative across all stages, with homeowners viewing it as too complicated and time-consuming to research and evaluate options.
• Information sources shift during the process: mass media (press and TV) are effective for raising initial awareness, but households in the action stage rely more on the Internet, construction industry professionals, and personal communications such as friends and colleagues.
• Investment payback is the most significant financial motivator, and its importance increases as households move toward implementation. Additionally, households utilizing KfW support are more likely to implement comprehensive retrofits and are less likely to drop energy efficiency options during the process.
• The German government aims to reduce the primary energy demand of buildings by 80% by 2050, which necessitates increasing the annual thermal retrofit rate from 0.8% to 2.0%.

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} }