Improving policy instruments to better tap into homeowner refurbishment potential: Lessons learned from a case study in Germany

Energy Policy 44 (2012) 406–415

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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 ¨ W), Potsdamer Str. 105, D-10785 Berlin, Germany Institute for Ecological Economy Research (IO

a r t i c l e i n f o

a b s t r a c t

Article history: Received 26 May 2011 Accepted 2 February 2012 Available online 22 February 2012

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.

Keywords: Energy efficiency Policy instruments Homeowners

1. Introduction Buildings are responsible for more than 40% of the energy consumption and greenhouse gas (GHG) emissions in Europe ¨ ¨ (Lechtenbohmer and Schuring, 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 ¨ Wirtschaft und households (BMWi [Bundesministerium fur 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%

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of all residential housing (Destatis, 2008) and 47% of all accom¨ ¨ modation units (Lechtenbohmer and Schuring, 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 distinguish 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 Warmeschutzverordnung (Thermal Insulation Ordinance)

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and followed by further additions over the decades. When the EPBD was initially introduced, in 2002, German energy savings regulations already fulfilled almost all of the prescribed requirements (CA EPBD, 2011). Likewise, funding programmes for energy-efficient space heating have enjoyed a long tradition in Germany, and the range of products has been broad compared to some other European countries (cp. Schaefer et al., 2000). Because of this pioneering role, it is thus worthwhile to take a closer look at German regulations and policies—their successes as well as shortcomings. In Germany, an extensive database of more than 7500 houses representing the residential building stock demonstrates that current refurbishment rates are rather low: the annual refurbishment rate for building facade insulation was roughly 0.8% between 2005 and 2008, and the annual rate for roof insulation 1.3% (Diefenbach et al., 2010). Taking into account these rates, it is questionable whether Germany will achieve the ambitious energy saving aims called for in the new German energy concept without ¨ Wirtschaft additional effort (BMWi/BMU [Bundesministerium fur ¨ Umwelt, Naturschutz und Technologie/Bundesministerium fur und Reaktorsicherheit], 2010). In order to estimate the success of Germany’s energy efficiency policy approach, one should view the current results in context by comparing them with refurbishment rates in other European countries: in northwestern Europe renovation rates for existing buildings have been about 1.2% during recent years with only 40–60% of these including significant energy performance improvement measures (Eichhammer et al., 2009); the situation in the German building sector thus appears comparable to and not significantly better than that of other European countries. This article presents the results of an analysis of policy instruments addressing the energy efficient refurbishment of single-family and semi-detached houses in Germany in the year 2010.1 The analysis was based on the question of whether the current instruments are able to overcome the refurbishment barriers homeowners face, as well as whether they focus on the most significant saving potentials; thus the barriers identified in the project and the various savings potentials are briefly discussed. Subsequently, the relevant policy instruments in Germany are introduced and their suitability for addressing these barriers and achieving the most desirable energy savings potentials are analysed and followed by recommendations on how they could be further improved and/or supplemented by additional new measures. The paper winds up with a discussion of the results and some final conclusions.

2. Refurbishment rates, savings potentials and barriers to energy efficiency improvements 2.1. Refurbishment rates A representative survey (N ¼1270) conducted during the course of the Enef-Haus project provided data on refurbishment rates for the period 2005–2009 specifically for single-family and semi-detached houses. Our findings show that the annual rate of all energy-related modernisation and refurbishment measures in this period has been roughly half that expected based upon theoretical refurbishment cycles. The theoretical refurbishment cycle is an estimate or assumption made as to how frequently a specific structural building part will have to be refurbished. 1 The findings presented are from the project Enef-Haus, which was funded by the German Federal Ministry of Education and Research under the auspices of the research programme Social–Ecological Research. Further information about the project is available at: www.enef-haus.de.

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The VDI 2067 guideline establishes 20 years as the theoretical duration of use for heating systems; for windows and facades a cycle of 40 years was assumed. The actual refurbishment cycle can obviously be greater, e.g. in the case of a still properly functioning heating system. The results, however, demonstrate, furthermore, that homeowners frequently refurbish building components such as facades and roofs without improving existing or adding new insulation measures and thus miss out on the most opportune moment to make relatively inexpensive energy efficiency improvements, as these areas of the building may not receive further refurbishment attention for years or even decades to come. If this trend continues, by 2020 less than 45% of the facade walls of single-family and semi-detached homes will be insulated and 100% participation will not be achieved until 2080 (cp. Weiss and Dunkelberg, 2010). With respect to climate protection, heating system modernisation and refurbishment measures are also less than satisfactory. Even recently, 0.5% of homeowners annually were still installing low-temperature boilers—almost as many as those installing the more efficient, state-of-the-art condensing boiler. The findings further show that energy-efficiency modernisation measures generally are carried out as isolated projects, with a comprehensive approach being rare. Another problem that could not be examined in the study but which further influences the overall impact of energy-efficient retrofitting is the quality of the measures implemented.

2.2. Key areas for potential savings In order to analyse the key areas for potential energy and GHG savings, a database of existing single-family and semi-detached houses in Germany (n¼ 2000) was used. The database documents buildings for which an Energy Performance Certificate (EPC) was issued in 2008 or 2009; it is not representative but represents a valuable approximation of the current single family and semidetached building stock, as no truly representative data is available for 2009.2 Energy efficiency calculations were carried out using a tool provided by the Institut Wohnen und Umwelt (IWU, 2006). The results demonstrate that three measures in particular are responsible for large reductions in the primary energy requirement and GHG emissions: insulation of facade walls, insulation of the roof, and deployment of renewable energy heating systems (see Table 1). User behaviour and further measures such as building automation were not taken into account due to the lack of adequate data; even so, their influence on the actual energy consumption must be considered (cp. Linde´n et al., 2006). Without any modifications to the existing heating systems, insulation of the building facade alone reduces the primary energy requirement by approx. 20%. This value and those presented in Table 1 take into account the current energy efficiency status of the dwellings (e.g. already existing insulation measures); thus the table illustrates still unused energy saving potentials. The values are therefore obviously lower than the energy reduction that can be achieved by refurbishing a fully unrenovated building. Regarding the primary energy requirement, the installation of geothermal heat pumps and solar heating systems would allow a further reduction of roughly 30%, the utilisation of wood pellets or firewood boilers even as much as 70%. All in all, the untapped primary energy savings of combined measures (heating system and building envelope) as well as the potential GHG savings are substantial. 2 A broader database (Diefenbach et al., 2010) of more than 7500 houses representing the entire residential building stock has only existed since 2010.

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Table 1 Mean values of existing primary energy saving potentials through various refurbishment measures in the single family and semi-detached building stock (kWh m  2 a  1). Calculations based on a database of 2000 houses. Year of building construction

o 1969

1969–1978

1979–1994

41994

Facade insulation EnEV 2009 PHa

70.6 77.2

38.7 51.5

26.1 36.2

16.7 24.7

Roof insulation EnEV 2009 PH

27.4 30.3

12.7 15.3

10.6 12.7

6.8 8.5

8.3 9.9

3.8 5.2

1.4 2.0

0.9 1.3

20.5 23.8

18.0 21.3

10.1 12.5

7.6 9.7

4.8 8.0

5.2 8.8

6.8 11.1

0.0 0.1

29.7 77.4 185.4

17.6 56.9 144.0

16.0 47.4 117.7

8.9 32.4 88.4

Upper storey ceiling insulation EnEV 2009 PH Basement ceiling insulation EnEV 2009 PH Window replacement Triple glazing Heatsaving glazing Heating systems Condensing boiler Heating pumps Wood pellet/briquettes a

Table 2 Total costs of various energy efficiency refurbishment measures vs. additional costs in comparison to a refurbishment without energy efficiency measures. ¨ Calculations based on Ebert and Bohnenschafer (2008) and Enseling and Hinz (2008).

PH ¼passive house standard.

The age of the building is an important factor when assessing potential for energy and GHG savings. The refurbishment of a pre1968 dwelling to EnEV 2009 standards would on average lead to a mean primary energy savings of more than twice that of a newer dwelling. The level of energy savings is further dependent on the refurbishment standard. Energy savings reached through thermal insulation measures at the level demanded by the Energy Conservation Act (EnEV) of 2009 were compared with those attained utilising the standards for passive houses. It should be noted, however, that 70–90% of the heating demand reduction due to refurbishment to passive house level can already be achieved through the implementation of the current EnEV standards for existing structures—depending on the date of construction. Inasmuch as many renovation projects still are undertaken without any energy-related measures whatsoever, a consistent approach in which refurbishment to EnEV standards would always be implemented whenever a renovation project is undertaken would be preferable to stricter, but much more rarely implemented standards. Uihlein and Eder (2010) likewise recommend that energy-saving measures always be implemented whenever refurbishment is undertaken, but they recommend installing the highest energy efficiency level possible. This makes sense on the face of it with respect to energy saving potential and cost effectiveness, however there are fundamental barriers that hinder the realisation of such measures. 2.3. Barriers to refurbishment and modernisation measures Another goal of the Enef-Haus project was to analyse the barriers and impediments that prevent or discourage homeowners from pursuing energy-efficiency improvement measures. In order to identify the most relevant barriers a survey of 1008 refurbishment cases was explored (Zundel and Stieß, 2011; Stieß et al., 2010); it revealed a number of different factors that play a decisive role in homeowner aversion to energy efficiency refurbishment measures, including: a lack of involvement or interest in energy efficiency issues, lack of financial means, aversion to borrowing, a lack of a long-term perspective, and various tangible fears including concern

Refurbishment/modernisation measure

Total costs (h) Additional costs (h)

Insulation Fac-ade Roof Basement ceiling

32,091 17,802 3715

16,046 4451 3715

Window replacement

16,800

1680

Heating systems Condensing boiler Heating pumps Wood pellets

5400–7,550 14,500– 22,600 15,600– 16,400

about the construction mess, associated stress, and dubious contractors. Socioeconomic factors such as age, education and income showed no significant influence on the refurbishment decision. These results are in contrast to observations in Ireland and Sweden by Scott (1997) and Martinsson et al. (2011), who found that householders with higher incomes and levels of education invest more in energy conservation measures. Financial barriers are another important group of disincentives. Current surveys indicate that most energy efficiency refurbishment measures are economically viable when carried out within the customary refurbishment cycle, as only the so-called additional costs need be compensated by energy cost savings (cp. Weiss and Dunkelberg, 2010). Still, more than half of those surveyed indicated that they are unsure whether refurbishment measures are profitable (Stieß et al., 2010). Furthermore, the high investment costs associated with renewable-energy heating systems, as well as the high costs for thermal insulation of facade walls and roofs, might present a problem for many homeowners; e.g. a high efficiency boiler currently costs approx. EUR 6000; for a heating pump system, procurement and installation costs of EUR 17,000–25,000 must be anticipated, depending on the specific technology (see Table 2). Many of those interviewed mentioned lack of sufficient financial resources or (further) credit availability as barriers to energyefficient retrofitting. High initial investment costs can thus lead to a massive reduction in the deployment of these particularly effective modernisation measures and therefore are a hindrance to the high efficiency levels recommended by Uihlein and Eder (2010). The Carbon Trust has likewise identified the high upfront costs of more efficient equipment as well as a lack of access to financing as important barriers (Levine et al., 2007). Huber et al. (2011) presented studies on barriers in which the authors cited a lack of knowledge of available technical solutions, high expenses, and an irregular or inconsistent policy framework as the most important barriers. In addition to those barriers directly faced by the homeowner, a series of building-related factors can also impede the implementation of modernisation measures. Historic preservation stipulations, the presence of balconies and stairways, and neighbouring property setback provisions (particularly with respect to facade walls) can all make the deployment of thermal insulation measures more difficult. There are also a number of physical obstacles that can restrict or hinder the installation of heating system technologies, e.g. lack of storage space for bioenergy fuels; roof orientation and slope are also factors that can make some buildings unsuitable for thermal solar. Of the homeowners surveyed, 17% cited structure-related impediments to energy-efficiency improvement measures; these barriers rarely

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fully hinder modernisation measures; however, they can increase time and cost expenditures and reduce the obtainable level of efficiency. Loga and Diefenbach (2007) estimated the achievable energy requirement to be approximately 13% higher than that obtainable without building-related restrictions. The barriers are thus numerous and highly diverse; each situation brings its own combination of homeowner concerns and other hindrances, and even just one of these barriers can be sufficient to hinder an energy efficiency refurbishment. Thus it is necessary to consider how well these various barriers are being addressed.

3. Analysis of existing policy instruments Policy instruments that seek to influence citizen behaviour can generally be subdivided into direct (regulatory) and indirect instruments. Regulatory policy instruments as defined here are those processes and activities ‘‘in which government requires or proscribes certain activities or behaviour on the part of individuals and institutions’’ (Reagan, 1987: 17). Instead of mandating specific behaviour on the part of individuals or institutions, indirect policy instruments incentivise the desired citizen activity or behaviour. Indirect policy instruments can further be subdivided into financial, procedural, and communicative instruments (Braun und Giraud, 2009: 162–169). In this article, in addition to regulatory policy instruments we focus only on the financial instruments. Procedural instruments have not yet played a significant role in the context of German residential building energy efficiency policy; communicative instruments, on the other hand, do so with respect to achieving energy efficiency targets in the EU and Germany; however, they encompass a number of highly diverse approaches such as marketing elements, online information tools, detailed billing, energy auditing and consulting, building labelling, and local-level leadership programmes. A comprehensive overview of these instruments can be found in Novikova et al. (2011), who address their functioning and distribution, as well as their potentials and shortcomings. There are arguments that can be made for as well as against regulatory and financial instruments—in the general as well as specific context. In general, regulatory policies are regarded as a cost and time efficient way to provoke societal behaviour towards an intended goal (see e.g. Braun und Giraud, 2009: 165). Furthermore, and particularly in the context of energy efficiency policy in the residential building sector, they contribute to the internalisation of the external effects and costs of GHG emissions emanating from this sector. Regulatory policies are therefore often viewed as the most effective way to induce homeowners to refurbish their ¨ homes energetically (Schaefer et al., 2000; Koeppel und UrgeVorsatz, 2007; IPCC, 2007; McCormick and Neij, 2009); however, this view sometimes underestimates the costs of implementation in the context of regulatory policy. In other words, the adoption of a regulatory policy that proscribes mandatory insulation standards for the exterior walls of buildings in and of itself can be a rather cost-effective measure; however, the advantages may be outweighed by the time and money required to ensure regulatory compliance, both on the part of the state and on the part of the citizens (see e.g. Braun und Giraud, 2009: 165). In light of the drawbacks faced by such a regulatory approach, financial instruments, in the form of incentives intended to encourage a change of behaviour, are often considered a better alternative or at least a good supplement to regulatory instruments. These financial instruments are here defined as ‘‘all forms of financial transfers to individualsy [that] can serve as incentives or disincentives for private actors to follow the wishes of government’’ (Howlett and Ramesh, 2003: 108). Financial

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incentives do attract less opposition and therefore are much less contentious than regulatory instruments; furthermore they can lead to better individual results than regulatory standards because they are able to provide an incentive to go beyond the standard demands of a regulatory policy instrument. On the other hand, costs for achieving the intended goals in the residential building sector can obviously be very high. Thus the level of government subsidy needs to be carefully balanced against the desired energy-efficiency measure to be implemented, such that a reasonable incentive/performance ratio can be achieved (Lee and Yik, 2004: 494; McGilligan et al., 2010: 1273); if such financial incentives are too large (or possibly not even necessary if, for example, a respective refurbishment measure is already profitable and would be implemented anyhow), they are prone to a freerider effect, thus yielding ‘‘a windfall for the recipients’’ (Howlett and Ramesh, 2003: 110). 3.1. Main policy instruments in Germany Significant regulatory laws in Germany include the German Energy Conservation Act (Energieeinsparverordnung; EnEV) and the German Renewable Energies Heating Act (Erneuerbare-EnergienW¨armegesetz; EEW¨armeG); the funding for these is provided at the federal level, by the federal states and/or by local authorities. At the federal level, two important programmes exist: Energy-efficient Renovation (‘‘Energieeffizient Sanieren’’), administered by the government-owned promotion bank KfW, and the Market Incentive Programme for Renewable Energies (‘‘Marktanreizprogramm’’). The Energy Conservation Act (EnEV), in effect since 2002 and frequently revised, governs energy efficiency building standards; it superseded two energy conservation policy instruments introduced after the oil crisis, the Thermal Insulation Regulation and the Heating System Regulation. One of the main tenets of the EnEV is the law of economic efficiency (cost recovery): accordingly, the EnEV can only mandate those construction or refurbishment measures for which a suitable cost recovery can be made within the course of new or refurbished components’ useful lifespan. The EnEV establishes specific numbers and calculation methods for determining the energy efficiency of residential buildings. Initially limited to heating demand, which is dependent on building layout and structural thermal insulation, there are now standards for the primary energy requirement, which additionally includes energy demand for hot water, and system efficiency, as well as the upstream process chain covering production, conversion, and energy transport. The building owner is thus free to choose whether the prescribed values are to be achieved by means of improved thermal insulation and conservation measures or through optimisation of the heating system technology. The demands for new buildings are more ambitious; in the case of an existing structure, the principle of conditional standards predominates: when modifications are to be made to a heated building, the standards for thermal transmittance coefficients (U values) of exterior structural elements must be met, an approach that is particularly cost-efficient as only the additional costs of the thermal insulation need to be amortised (Maßong, 2009); alternatively, the standards for the primary energy requirement can be met. In the case of a transfer of ownership, additional low-cost measures, including insulation of hot-water distribution pipes and the ceiling over the upper floor, are compulsory. The EnEV furthermore includes requirements pertaining to the energy efficiency of newly installed central-heating boilers in existing buildings; those standards, however, can be met even by condensing boilers. Since 2007, an energy performance certificate (EPC) documenting the energy demand of residential dwellings has also

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been mandatory; in case of a sale or rentals as well as modernisation or expansion measures for existing buildings, it has only to be presented upon demand. A further regulatory instrument, which went into effect in 2009, is the Renewable Energies Heating Act (EEW¨ armeG). The law mandates a specific share of renewable energy deployment regarding the heating and cooling demand of newly constructed buildings. Requirements for existing buildings are not a part of the law, but they may be stipulated at the regional level; the ¨ federal state of Baden-Wurttemberg already has mandatory requirements for existing buildings and in three further federal states this is under consideration. In the light of the low rate of new construction in Germany, the currently limited focus of the law on new construction leads to minimal effect. The KfW programme Energy-efficient Renovation makes available low-interest loans and subsidies for refurbishment measures that lead to an increase in a building’s energy efficiency. The level of funding is based upon the efficiency class a building achieves after modernisation (KfW Efficiency House 85, 100, 115, or 130; KfW, 2010)3; the number refers to the maximum allowed percentage of the primary energy requirement as compared to the EnEV 2009 standards for new construction, and attainment of the efficiency goals following completion of refurbishment must be verified by a professional appraiser. As an alternative funding is also available for isolated measures; these must likewise exceed the requirements set by EnEV for refurbishment of existing structures (by about 15–25%). The individual measures can be carried out in combination (KfW, 2010); subsidies can be applied for directly from KfW; where a construction loan is involved, the processing is taken care of by the bank providing the loan. The conditions of the programme have changed frequently during the last years, and future financing has often been uncertain. This is true even now although the financial means therefore should derive from a special federal fund. The Market Incentive Programme (MIP) offers investment subsidies for the construction or addition of solar panels, biomass boilers, and heat pumps (BAFA, 2010). For buildings with a low primary energy requirement, in addition to the initial funding an efficiency bonus is available—a logical approach in so far as the deployment of renewable energy heating in buildings having a low energy requirement will lead to significantly smaller savings in heating costs as compared to those with a high energy requirement. Furthermore, for the first-time installation of a condensing boiler in conjunction with a solar thermal energy system, a boiler exchange bonus is offered, something that older buildings particularly profit from. Beginning in 2008, the subsidies were massively promoted as the ‘‘climate premium’’. The number of applications in recent years rose dramatically, reaching a maximum of 256,976 applications for ¨ funding in 2009 (BMU [Bundesministerium fur Umwelt, Naturschutz und Reaktorsicherheit], 2010). Due to a lack of funding, however, the programme was interrupted in the spring of 2010 for several months. 3.2. Analysis of the instruments’ shortcomings Before presenting the results of our analysis of the instruments’ shortcomings, it should be noted that the instruments presented certainly do contribute to an increase in the energy efficiency refurbishment rate. Regular evaluations of EnEV and the KfW programmes prove the positive impacts of these instruments and provide numbers for the resulting energy savings (e.g. Kuckshinrichs et al., 2010; Clausnitzer et al., 2007, 2008; 3 Since July 2011, the stricter efficiency standards Efficiency House 55, 70, 85, 100 and 115 have been in effect.

Table 3 Overview of how existing instruments address the main barriers to refurbishment. Regulatory law

Lack of involvement/interest Aversion to borrowing Insufficient financial resources Lack of a long-term homeowner’s perspective Tangible fears & concerns Structural/technical barriers

Standards (EnEV, EW¨armeG)

EPC

x (x)

(x)

(x)

xa

(x) (x)

Financial instruments Funding programmes

(x) x (x)

(x)

a

The EPC should have a positive effect because a high energy efficiency rating for a building should lead to a higher market value in the real estate market.

Diefenbach et al., 2005). However, these evaluations face several problems, e.g. the question of how to separate the net effect of a specific instrument from the effects of the other instruments currently being in force in this sector. Furthermore, the evaluations only regard net effects, thus neglecting, for example, freerider effects. As ours was a qualitative analysis, we will not present energy saving potentials to be achieved by adapting existing or adding new policy instruments. Despite improvements to the aforementioned policy instruments in recent years, there are still some deficiencies, including the need for a greater focus on the barriers single-family and semi-detached homeowners face, as well as on those measures offering the greatest potential for savings in existing buildings. Table 3 gives an overview on how the instruments presented address the already addressed barriers. Regulatory law principally addresses those with little or no interest in such measures (see Table 3). In practice, however, the effect is limited; one reason is that EPBD and EnEVl 2009 mainly address the energy efficiency of new buildings and older buildings undergoing major renovations (see also Uihlein/Eder, 2010). As shown earlier, a key issue concerning regulatory instruments is the costs and difficulties associated with enforcement of mandatory standards—particularly in existing structures. In the case of EnEV, various studies assume a substantial enforcement ¨ deficit (Diefenbach et al., 2005: 117–118; Burger et al., 2006: 112; Ziehm, 2010). Due to a lack of empirical data, it is impossible to specify exact numbers in this context,4 but the German government has recognised the importance of this aspect. Policy-makers, therefore, made strengthening of enforcement an explicit goal when the EnEV was amended in 2009. To some extent, this enforcement deficit can be explained by weaknesses in the policy formulation; these were addressed as a part of the 2009 EnEV amendments: chimney sweeps now must check whether heating systems meet EnEV 2009 standards; contractors who implement energy saving measures are likewise responsible for ensuring that the measures meet the prescribed standards. These are sensible measures that may lead to reductions in the enforcement deficit. The provision mandating random audits, however, was removed 4 It is virtually impossible to deliver reliable numbers on the enforcement ¨ deficit of the EnEV or EEWarmeG in the building stock since data collection on this issue is hardly feasible; however, all studies dealing with this aspect as well as all experts that have been interviewed on this issue confirm that the enforcement deficit is a major drawback of these regulations; for example, the study of Ziehm (2010), which exclusively deals with this issue, concludes that in both cases, EnEV ¨ and EEWarmeG, the enforcement weaknesses will effectively prevent the regulations from achieving their goals. Consequently, we came to the conclusion that it is essential to consider this aspect even though this cannot be based on exact numbers.

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from the EnEV 2009 draft. This limits the impact of new measures, as both contractor and homeowner still can be certain that any infringement of the EnEV standards will neither be pursued nor penalised. At the same time, implementation of EnEV has made clear the more traditional ‘‘real’’ enforcement problems of such regulations: significant deficiencies on the part of the enforcement authorities—due, above all, to a lack of sufficient personnel and equipment, as well as insufficient professional training on the part of the public employees. To some extent, these problems cannot principally be traced back to the formulation of the EnEV regulations, but rather to the desire for deregulation and ‘‘lean’’ administrations. Even so, the ignorance of the authorities with respect to the relevant cases is an entirely EnEV-specific problem. Many of the specifications address refurbishment situations about which the authorities have no knowledge. Furthermore, since those homeowners who generally show little interest in retrofitting rarely carry out extensive refurbishments to facade walls or roof, the exclusive coupling of the standards to these specific refurbishment situations leads to a minimal impact among this group of homeowners. Clearly, the problem of EnEV enforcement is, to a certain extent, rooted in structural problems inherent in the type of policy instrument and therefore hardly resolvable. But, insufficient provisions in the EnEV itself regarding enforcement are also clearly responsible. Strengthening of enforcement under the EnEV 2009 amendment, therefore, has indeed been a proper and useful approach to addressing the deficit, but its effectiveness will be modest since important provisions intended to address lack of knowledge on the part of enforcement personnel and the introduction of a random audit procedure were both left out. One particular criticism of the energy performance certificate (EPC) in Germany has been that the co-existence of two variants – an energy-consumption as well as an energy-demand certificate – and differing methods of computation limit the comparability of a building’s energy-efficiency qualities. A second criticism is that the German certificate, which lacks efficiency classes, is less informative than those issued in other European countries. Additionally, the basis for recommendations is perceived as inadequate due to a common lack of sufficient fundamental data (Diefenbach et al., 2008; Wolff, 2009). In line with these criticisms, evaluations of the EPC in Denmark, where the requirement for residential buildings has existed since 1997, have concluded that in the end these have little influence upon a building’s energy efficiency (see Gram-Hanssen and Christensen, 2010). The implementation of modernisation recommendations at the time of sale, in particular, are hindered, according to Gram-Hanssen and Christensen (2010), because it is the seller and not the buyer who is in contact with the issuer of the certificate; thus no personal relationship is established between buyer and issuer, resulting in a lack of faith in the issuing authority. Another survey in five European countries proves that many buyers are either not aware of the EPC when buying a house, or are not aware that the EPC includes specific recommendations regarding energy efficient refurbishment measures (Adjei et al., 2011). Still, when homeowners are familiar with the EPC and the related energy efficiency recommendations, the certificate will influence the decision making process slightly in favour of energy efficient measures (Adjei et al., 2011). The funding programmes specifically address the funding barrier to modernisation measures (see Table 3). The Enef-Haus survey demonstrates, however, that subsidy programmes first and foremost influence the most highly motivated homeowner groups; thus there are concerns about a not-so-small free-rider effect and the resulting inefficient allocation of financial resources. Furthermore, until recently, the programmes have largely supported refurbishment measures that only minimally exceed the legally required standards and have scarcely focussed

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on those refurbishment measures and classes of structures offering the greatest potential for energy savings—an approach that for reasons of cost effectiveness and climate change protection would be desirable. However, both standards have been tightened and fewer measures have been financed since the last change of the programme in July 2011. Still, with respect to climate protection policy, the funding situation in 2010 for heating systems in particular was less than satisfactory, as funding for the market incentive programme stopped for several months. Thus, there was a period of time during which renewable energy heating systems were not being funded, but support for the installation of condensing boilers via the KfW programme continued. The funding halt for the market incentive programme points to a main prerequisite of (successful) subsidy programmes in particular: reliable funding and thus ensured continuation. In addition to individual consideration of these instruments, their interrelationships and interdependencies need also be taken into account; there are strong links, for example, between the ¨ EnEV, the EEWarmeG and the MIP regarding their approaches to achieving the interrelated goals of greater deployment of renewable energies and higher energy efficiency in the building sector (see e.g. Pehnt et al., 2009: 217–272 for an overview). In general, these links provide opportunities for synergies in the policy mix by more strongly interconnecting the instruments, e.g. regarding the enforcement of regulatory policies (see e.g. Weiss and Vogelpohl, 2010: 37), that have so far not fully been exploited. Although communicative instruments are beyond the scope of this study, it might be useful to consider their potential to address and mitigate the above-mentioned barriers. Communicative instruments can primarily address lack of involvement or interest by providing information through various channels. Personal communication, for instance through contact with an energy advisor or consultant, can additionally mitigate tangible fears and concerns.

4. Recommendations for the improvement of existing policy instruments Two promising approaches for increasing the rate of energy efficient modernisation with respect to regulatory law would be: strengthening enforcement of the EnEV by means of random audits and better utilisation of suitable refurbishment occasions—particularly at the time of transfer of ownership, which represents a unique window of opportunity during which a greater willingness to carry out energy efficiency improvement measures often exists. Thus in the continuing development of the EnEV regulations, further requirements should be linked to transfer of ownership; one possibility is an obligatory energy consultation. At such a session an energy efficiency consultant could discuss the current energy efficiency status of the structure with the new homeowners and, where necessary, advise them on the need for action in this context. If such a consultation were mandatory, even those could be addressed who due to lack of interest or involvement would otherwise not make use of such services. Another possibility for exploiting this window of opportunity would be to tie to the transfer of ownership specific additional energy saving measures – especially those with high savings potentials – or a specific energy demand level for the building to be achieved within a limited time frame (e.g. within 24 months of new ownership). This seems more appropriate in this context than requirements for individual components and measures, since it allows those measures to be chosen that are most cost-effective and suitable for the individual situation. So far, only measures with low overall energy saving potentials, such as the insulation of hot-water distribution pipes, are required

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with transfer of ownership. A linkage to transfer of ownership would also facilitate enforcement of the relevant regulations, as these occasions are known to the authorities. Furthermore, stronger requirements, e.g. specific measures or a specific energy demand level, would have another positive effect: those buildings with a high energy demand level would lose market value due to the investments the new owner would be obligated to make upon transfer of ownership; this could motivate homeowners with an uncertain or short-term perspective to invest in energy efficiency refurbishment measures. With a view to exploit the energy savings potentials identified, care should be taken in preparing the regulations to set the standards at an appropriately high mark, as completion of these refurbishment measures will effectively lock these energy efficiency levels in for a long period of time. In this respect, the EnEV regulations dealing with the building envelope are presently satisfactory, although in line with market developments, a successive increase in the standards – as was announced for EnEV 2012 – seems reasonable. But there is a strong need for improvements to the heating system standards for existing structures—at the national level the required installation of renewable energy heating systems presently only applies to new construction (EEW¨armeG) and thus overlooks an opportunity for an important climate protection measure. Some other improvements might further derive from EU regulations in the coming years. The ecodesign directive as discussed, however, will not lead to a much stricter regulation regarding the efficiency of fossil fuel boilers in smaller houses. Still, energy labels (product labels as well as installer labels) might have some influence on homeowners. A strengthening of the regulatory law, however, leads to greater difficulties for socially vulnerable groups; thus these modifications should be combined with appropriate social support measures, e.g. a restructuring of the existing funding programmes or the provision of additional public funds for hardship cases. For funding programmes to be cost effective they should first and foremost focus on the primary saving potentials—thus above all older buildings. A clear promotion of excellence, particularly for the highly motivated refurbishment group, would be appropriate; the prerequisite for such subsidies, for example, could be the attainment of higher efficiency standards. To expand modernisation activities among low-income homeowners, however, a programme supporting measures meeting lower standards and addressing social criteria, e.g. income level, would appear to be necessary. Kuckshinrichs et al. (2010) point out that the provision of public funding for purposes such as the KfW promotional programmes leads to an additional social return in the form of tax revenues and social security contributions; thus in the long term these public investments can be considered a successful use of public resources. Therefore sufficient public means should be made available to support all homeowner energy efficiency refurbishment activities; furthermore, to ensure that these promotional programmes reach all possible participants, including those expressing little interest in energy conservation issues, the level of effort necessary for participation must be kept low. Thus there is a need to simplify the application process, particular with respect to loans at local banks. Last but not least, predictability and continuity of the funding schemes are important to homeowners of single family and semi-detached houses, as they often carry out refurbishment measures one step at a time.

5. Recommendations for suitable supplementary policy instruments The analysis of existing instruments showed several shortcomings, some of which can be solved through improvements.

Still, one central constraint remains: (the lack of) sufficient means to finance the tremendous refurbishment activities necessary to satisfy policy goals with respect to homeowners as well as the obligations of public funding. Thus an investigation of further instruments currently in discussion or already present in Germany but being given little attention, as well as measures in use in other countries, was carried out. Several supplementary instruments have been identified that might help to solve the financial constraints: public benefit charges, energy saving commitments, energy efficiency funds, the Home Ownership Pensions Act, and energy contracting. One possibility for additional financial resources is the so-called energy saving commitments of energy suppliers or electricity network operators which already exist in some EU countries. Energysaving projects in the household are one way for suppliers to meet these obligations. Vine and Hamrin (2008) state, however, that because of how savings are calculated, these obligations could lead to investments in short-term, inexpensive measures, instead of those with a longer-lasting, broader impact. A second disadvantage in this respect is the probable lack of impartiality on the part of the energy suppliers and network operators, who after all, are in the business of providing (fossil) fuels. For the above-mentioned reasons, only the following instruments were recommended in the course of this analysis as being practical extensions to existing approaches:

 Energy efficiency funds are institutions for bundling and pro-



moting energy efficiency measures from one or more sectors. The establishment of an energy efficiency fund could also help ensure the continuation of subsidy programmes and lead to their improved coordination and communication (see Irrek and Thomas, 2004). According to Gram-Hanssen and Christensen (2010), the energy efficiency fund in Denmark has fulfilled all expectations; until recently it focused on saving electricity, but it was extended to include energysaving refurbishments in 2010. From the viewpoint of service providers and contractors in the energy efficiency sector, a monopolisation of offerings through such an energy efficiency fund could be a problem; there is also the question of financing: existing efficiency funds in other countries, e.g. Denmark and Great Britain, are generally financed by means of surcharges on energy prices and network usage fees (Irrek and Thomas, 2004). In 2011, an energy efficiency fund was implemented in Germany, not as an independent institution, however, but rather as an extraordinary federal budget item. Subsidies for the refurbishment activities of private households, however, are not a part of the planned activities, but improvements to the dissemination of information, energy checks and the EPC are included. A federal special fund is intended to provide the financial means; still adequate funding is uncertain at the moment. The Home Ownership Pensions Act (‘‘Eigenheimrentengesetz’’), which until now has only permitted use of the so-called Riester pension for the acquisition of real estate, could offer an additional possibility for financing homeowner energy efficiency modernisation measures, as such long-term money-saving home improvements can also be viewed as a form of retirement provision. Thus, financial means do exist for funding more extensive refurbishment measures, particularly those offering a greater energy savings potential, without the need to resort to additional large-scale public expenditures. As the costs of such measures, however, often cannot immediately be recovered through property appreciation on the real estate market, special consideration must be given to some form of security to back these investments up in the case of refinancing due to a sale.

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 Another possibility for financing energy efficiency refurbishment measures is energy contracting. The transfer of risks from the home owner to the contractor, means that energy contracting also would provide a way to reduce or eliminate some of the tangible risks homeowners face; however, there are barriers associated with this service in single-family houses, in particular for those refurbishment measures with the greatest potential (e.g. insulation of the roof or facade walls). Thus energy contracting for residential buildings currently mainly focuses on heating systems and often results in the installation of low-temperature and condensing boilers instead of renewable energy heating systems. Therefore, before expanding energy contracting services, a model suitable for these refurbishment measures and single-family and semi-detached homes first needs to be developed and tested.

6. Discussion and conclusion The present article focuses on the case study Germany, a country whose regulation of building energy efficiency is often seen as fairly progressive. The main results, with respect to energy savings potentials, homeowner barriers, and the outlook for the various policy instruments, however, are certainly also valid for other European countries. Residential buildings and especially existing single-family and semi-detached houses in Germany offer significant potential for large energy savings and thus reductions in GHG emissions. Three potential energy-saving measures in particular significantly address reduction of the primary energy requirement: insulation of facade walls, insulation of roofs, and the use of renewable energy heating systems. These measures, as well as older houses – those constructed before 1979 – should be given priority from the point of view of climate protection. Unfortunately a number of barriers, including homeowner lack of involvement with the issue, insufficient financial resources, aversion to borrowing, lack of a long-term homeowner’s perspective, as well as structural and technical barriers, have led to refurbishment rates only half of what was anticipated and are needed to reach desired policy goals. Since the empirical evidence shows that house owners have an aversion to borrow or are not sufficiently well-informed about the profitability of refurbishment measures, the government should provide incentives in order to motivate homeowners to refurbish. Otherwise the market system does not ensure an optimal rate of refurbishment. Policy instruments that provide house owners with incentives to increase the rate of refurbishment can be welfare-enhancing in case the free-rider effect is small. The results of our analysis of existing policy instruments in Germany (EnEV, EEW¨armeG, the KfW programmes, the Market Incentive Programme) however indicate some deficiencies in the policy instruments themselves; these are for the most part in line with the results of other studies dealing with this topic. Although regulatory policy instruments have tremendous potential to curb GHG emissions and do so cost-effectively, at least from a governmental perspective, problems arise regarding compliance with the regulatory prescriptions and enforceability; thus questions arise with respect to their actual effectiveness. The enforcement problems are typical for regulatory law in the building sector and are mainly rooted in limited resources as well as lack of knowledge and reluctance on the part of the supervisory authorities, as studies from other countries confirm (see e.g. Klinckenberg and Sunikka, 2006: 15–16; Ellis et al., 2009: 347). However, even though such issues are to a certain extent inevitable, possibilities do exist to reduce these enforcement deficits, e.g. the introduction of random audits, and these should be more systematically exploited.

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A similar conclusion can be drawn with regard to the financial instruments used in Germany to boost residential building energy efficiency. Though these instruments have been well received by German homeowners, it remains questionable as to whether this money was well spent, since it cannot be known whether at least some of these measures would not have been taken anyway; such free-rider effects have rather often been observed in the context of financial incentives for energy efficiency measures in the building sector (see e.g. Schaefer et al. 2000; Klinckenberg und Sunikka, 2006); because of questionable cost effectiveness, financial instruments are often credited with a smaller positive impact in comparison to regulatory measures in this sector (see e.g. ¨ Schaefer et al. 2000; Koeppel und Urge-Vorsatz, 2007). Nonetheless, they can be particularly helpful in kick-starting new technologies in the early phases of their market launch ¨ (Koeppel und Urge-Vorsatz, 2007; McCormick and Neij, 2009); furthermore, as this study has shown, they play an important role in the policy instrument ensemble by encouraging those homeowners who are willing but not financially able to go beyond the mandatory standards to actually do so. This particularly is the case when the financial incentives are predominantly geared towards financially disadvantaged homeowners since this reduces the danger of free-rider effects. Subsidy programmes to date, however, have first and foremost influenced the most highly motivated refurbishment group. All in all, one could conclude that our analysis of the policy instruments used in Germany to boost residential building energy efficiency have shown somewhat predictable results, i.e. the problems and deficiencies of various policy instruments in this sector that other studies have already detected. The added value to be derived from this study is the connection drawn between these – at times inevitable – deficiencies in the policy instruments and the specific barriers homeowners face regarding energy efficiency refurbishment as well as to those measures offering the greatest potential for savings in existing buildings. This broader approach tells us not only what the problems are but also provides clues as to the barriers and measures that need to be focussed on and systematically addressed—be it by means of existing or new instruments. Furthermore, a focus on the barriers that homeowners face demonstrates that the question should be not only what sort of instruments are effective, but rather which mix of instruments will best enable us to surmount the various barriers. Based on this approach, some changes have been proposed. With respect to regulatory instruments: (1) Random audits: These could improve implementation and enforcement of existing regulatory standards and (2) refurbishment occasions: These should be better made use of, particularly the time at transfer of ownership. In the continuing development of EnEV regulations, further requirements addressing change of ownership should be established. With respect to financial support instruments: (1) special funding should be made available to highly motivated homeowners willing to achieve a high standard of energy efficiency; (2) an additional programme is needed with support for measures meeting lower standards, combined with consideration for social criteria, e.g. income level. A decisive problem with respect to financial incentives was and still is their funding. Although a special fund has been established, financing for the existing programmes remains uncertain for the coming years. Finally, (3) furthermore, additional funding through, e.g. an energy efficiency fund, an extension of the Home Ownership Pensions Act to encompass energy efficiency modernisation or energy contracting, could help to finance the tremendous refurbishment activities necessary to meet the envisaged policy goals. Although there have been some evaluations of the primary policy instruments boosting energy efficiency in the building sector, they mainly focus on individual instruments and neglect

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the crucial criteria: the regularly conducted subsidy programme evaluations examine the boosted refurbishment measures but do not explore free-rider effects and thus the relevance or appropriateness of the funding (cp. Kuckshinrichs et al., 2010; Clausnitzer et al., 2007; Diefenbach et al., 2005). Regarding regulatory instruments, little is known about what the percentage of homeowners infringing on the EnEV regulations. To further improve the effectiveness of policy instruments, more attention should be paid to these crucial aspects. In autumn 2010, the federal government in Germany adopted an energy roadmap (‘‘Energiekonzept’’; BMWi/BMU [Bundesministerium ¨ Wirtschaft und Technologie/Bundesministerium fur ¨ Umwelt, fur Naturschutz und Reaktorsicherheit], 2010); among the goals it calls for, is an 80% reduction of the primary energy requirement in the building sector by 2050. The present article shows that due to the various refurbishment barriers homeowners are facing, a combination of instruments of various types – including regulatory instruments – is necessary to enhance the energy efficiency of single family and semi-detached houses. This result is transferable to other European countries; as we showed in the Section 1, others are struggling with similar problems in trying to enhance energy efficiency refurbishment activities.

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