C O N T E X T 1 4 9 : M A Y 2 0 1 7 21 assessments of domestic buildings, existing qualified domestic energy assessors were required to take a threeday training course. For new entrants to the industry, without construction experience, the course, which also qualifies participants to produce energy performance certificates, was eight days long. Specific training for the assessment of historic buildings was not required. The short lifespan of the Green Deal, the short duration of assessor training courses and the fact that no specialist historic building training was needed indicate the level of expertise and experience of retrofit professionals generally, and highlight why tools such as the wheel are of particular importance in the UK. Let’s take a look at related policies in Germany. The contrast to training requirements for building energy assessors is stark. Accreditation, available only to architects, engineers and master craftsmen, requires successful completion of a course of 240 hours. (In Germany the roles of building or quantity surveyor are still largely part of the architect’s job.) The specialist training as building energy advisor for monuments is an additional 54 hours. Competency levels of building energy advisors in Germany, therefore, are generally higher than in the UK. Perhaps a Retrofit Guidance Wheel is less urgently needed (although a German version would certainly be good to have also). As with the Green Deal, assessors’ accreditation is required for projects seeking specific public funding support.The German government has created, through the government-owned bank KfW, a programme of grants and loans, called KfW Efficiency House, to ‘promote the refurbishment of houses if after refurbishment they do not exceed a specific energy requirement for a comparable new house’.2 Loans are offered at market-competitive rates with early repayment subsidies. ‘In order to meet the high energy standard of a KfW Efficiency House, extensive investments such as the renewal of heating systems, thermal insulation and replacement of windows, are usually required.’3 Acknowledging, however, that retrofitting historic properties without destroying their special character is challenging, a specific programme has been created for historic buildings: KfW Efficiency House Monument. The applicability of the monument programme is not limited to listed buildings, but also covers other ‘especially preservation-worthy building fabric’, such as buildings in monument groups, conservation areas, townscape statues areas and listed historic city centres or buildings deemed otherwise preservation-worthy by local governments. To be generally eligible for KfW Efficiency House Monument funding, a retrofitted building generally needs to achieve at least a benchmark annual primaryenergy consumption of 160 per cent and a transmission heat loss of 175 per cent when compared to a calculated reference building. Similar to the use of the calculation method in the UK, the reference building is a virtual new-built identical to the existing building in terms of geometry, orientation and floor area, but with a building envelope and technical building system achieving the energy performance values prescribed by current legislation. Funding, though, can also be made available for building retrofits which, for conservation reasons, can not achieve the minimum requirements. It is not limited to building retrofit measures and can also be used for urban infrastructure improvements. Where building retrofits can not achieve the targeted savings of carbon dioxide emissions, decarbonisation of energy sources, possibly off-site, can be an option. This strategy is being considered, for example, in Ludwigsburg, a city in Baden-Württemberg, for its baroque city centre. As appropriately retrofitting the historic buildings in the city centre is costly and difficult, the municipal government works on extending its communal heat distribution network further into the centre, in order to connect more historic buildings. Powered by a wood-fired, low-emission plant, the primary-energy consumption associated with the network is so small that historic buildings connecting to it can achieve the funding conditions of KfW Energy House Monument with only limited improvements made to the historic building fabric. Similar opportunities exist in other German cities. The heat distribution network in Hamburg, for example, serves many of the harbour warehouses, which were inscribed as UNESCO world heritage in 2016. (The installation of a heat distribution network in the world heritage site Hanseatic Town of Visby, on the Swedish island of Gotland, featured in the July 2016 issue of Context.) Energy generation off-site, however, always results in transmission losses. The development of ever-smaller, less-costly and more-efficient plants makes their installation in historic areas more feasible, especially where renewable energy sources can be used, such as air-source heat pumps, geothermal energy technology and solar photovoltaic systems. Installing such technologies in a historic setting often has an adverse visual impact on culturally significant building or urban elements,4 but careful design can help to mitigate this. References 2 KfW (2016) Existing properties: housing, home modernisation and energy conservation: energy-efficient refurbishment 3 ibid 4 Hermann, C, and Rodwell, D (2014) EFFESUS methodology for assessing impacts on energy-related retrofit measures on heritage significance, The Historic Environment, 5(2) A map of a Bavarian village identifying roof areas suitable for photovoltaic panels to inform master planning which takes both renewable energy generation and building conservation into account (Image: ArchitekturbüroWerner Haase, Karlstadt)
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