Improving policy instruments to better tap into homeowner refurbishment potential: Lessons learned from a case study in Germany Julika Weiss n , Elisa Dunkelberg, Thomas Vogelpohl Institute for Ecological Economy Research (IO ¨ W), Potsdamer Str. 105, D-10785 Berlin, Germany article info Article history: Received 26 May 2011 Accepted 2 February 2012 Available online 22 February 2012 Keywords: Energy efficiency Policy instruments Homeowners abstract Increasing energy efficiency in residential dwellings remains one of the top climate protection priorities in many European countries. In Germany regulatory instruments and subsidy programs, together with communicative instruments, represent the most important measures for motivating homeowners to pursue energy-efficient retrofitting—to date, however, with little success; a tremendous potential for energy savings still exists particularly in the category of single-family houses. The present article primarily addresses the question of how to improve or supplement the political instruments in order to increase refurbishment rates and tap these potential savings; it presents the results of an analysis of existing policy instruments in Germany focussing on the most promising types of building and refurbishment measures that also takes into account the barriers responsible for the discrepancy between potential and actual refurbishment rates. It is shown that consideration of the specific peculiarities and situations homeowners face, coupled with an analysis of the energy saving potentials of their buildings, offers valuable insights and is critical for evaluating policy instruments and finding the mix of instruments that will purposefully encourage the most effective refurbishment measures. Drawing on these results, recommendations for the improvement of current policy instruments and implementation of new instruments are provided. & 2012 Elsevier Ltd. All rights reserved. 1. Introduction Buildings are responsible for more than 40% of the energy consumption and greenhouse gas (GHG) emissions in Europe (Lechtenb ¨ ohmer and Sch ¨ uring, 2011). Of this, residential building stock represents the most important aspect, with an EU-wide average of 30% of total final energy consumption (Itard et al., 2008). Existing buildings are of particular importance for effective GHG mitigation simply because they will continue in existence for some time into the future. In the United Kingdom, for example, it is estimated that approx. 75% of all dwellings existing in the year 2050 already exist today (Ravetz, 2008). In Germany, more than a quarter of total end-user energy consumption is attributed to the provision of heating and hot water in private households (BMWi [Bundesministerium f¨ ur Wirtschaft und Technologie], 2007); single-family and semi-detached houses in Germany are particularly significant for the reduction of GHG emissions. This is due to two reasons: first, the specific heating requirements per square metre of living space for single-family and semi-detached are higher as compared to multi-family dwellings, and secondly, these two building types make up 80% of all residential housing (Destatis, 2008) and 47% of all accom- modation units (Lechtenb ¨ ohmer and Sch ¨ uring, 2011), and thus represent the largest share of building stock in Germany. In consequence, existing single-family and semi-detached houses are particularly relevant for climate protection. Since the demolition of an existing building has a negative environmental impact, refurbishment of residential buildings is commonly recommended (cf. Power, 2008). Various energy refurbishment measures are available. In this article, we distin- guish between measures that address the building envelope (insulation of exterior walls, roof, upper storey ceiling, basement ceiling, and window replacement) and measures that deal with the heating system (installation of a high-efficiency boiler and heating systems based on renewable energy). Other authors as, e.g. Roberts (2008) distinguish between passive measures (mainly those involving the building envelope) and active measures (i.e. the heating system). At the EU level, the Energy Performance of Buildings Directive (EPBD), introduced in 2002 and recast in 2010, establishes the framework for the EU countries’ national policies on building energy efficiency. Germany’s energy savings regulations are often regarded as fairly progressive because Germany was one of the first EU countries to implement such policies (Eichhammer et al., 2009), beginning in 1977 with the implementation of the so- called W ¨ armeschutzverordnung (Thermal Insulation Ordinance) Contents lists available at SciVerse ScienceDirect journal homepage: www.elsevier.com/locate/enpol Energy Policy 0301-4215/$ - see front matter & 2012 Elsevier Ltd. All rights reserved. doi:10.1016/j.enpol.2012.02.006 n Corresponding author. Tel.: þ49 30 8845940; fax: þ49 30 8825439. E-mail address: julika.weiss@ioew.de (J. Weiss). Energy Policy 44 (2012) 406–415