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Department of Architecture

'A Critical Appraisal of Germany's Thermal Retrofit Policy,Turning Down the Heat ': a new book on energy policy by Minna Sunikka-Blank and Ray Galvin

Germany is seen as a leader in thermal retrofit policy and practice, but how effective is its approach? A Critical Appraisal of Germany's Thermal Retrofit Policy examines this policy in context and assesses its effectiveness. The book finds that technical constraints and the costs of retrofitting still reduce the rate of progress. The book introduces a new concept of ‘prebound effect’. There is a gap between the predicted energy use, based on the technical performance of a dwelling, and how much a household living in it actually consumes. On average, a German household consumes 30% less than estimated based on the Energy performance Rating (EPR). This gap increases and the EPR increases, so that households living in the most energy inefficient houses consume much less than thought. As you cannot save energy that is not being consumed, this is likely to increase payback times and result in less savings. The book finds that most energy use reductions in Germany took place in non-retrofitted households, showing that people are already adjusting their behaviour.

The book suggests a new policy paradigm that would encourage a better balance of partial and comprehensive retrofits, utilizing household behavior changes based on a better understanding of fuel saving motivation and fuel price elasticity. In this approach, the thermal building regulations would be made more flexible, following the ‘CUT-model’ so that policymakers and planners would:

- Promote partial, transitional and cost-optimal retrofits, which are more certain to pay back through fuel savings if they are appropriate to building typology and homeowner budgets.

- Invest more heavily in educating households to heat economically, learning from the prebound effect so as to maximize the utility of the homes they currently occupy, and base payback time calculations on actual consumption.

- Promote comprehensive retrofits for reasons other than economic gain, focusing

instead on the comfort and environmental benefits of energy-efficient homes.

Contents: 1. Introduction; 2. Development of German Retrofit Policy; 3. German Retrofit Policy in Context; 4. The Technical Potential and Limitations of Thermal Retrofits in Germany; 5. The prebound effect: discrepancies between measured and calculated consumption; 6. The economics of thermal retrofits in Germany; 7. Why is domestic heating fuel consumption falling in Germany? 8. How fuel price elasticity affects the economics of thermal retrofits; 9. Conclusions.

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