*3.3. UK's Regulatory Approaches on Energy-E*ffi*cient Retrofitting of Built Heritage*

BS 7913:2013 Guide to the Conservation of Historic Buildings is the first British Standard to address the conservation and energy efficiency of heritage buildings with historically appropriate materials and techniques [31]. In 2017, EN 16883:2017 [32] was transposed into UK legislation. The standard is intended for local authorities, building practitioners and building owners and provides a step-by-step guide to the conservation and refurbishment of historic buildings. The heritage-built environment has been identified in government policy as a key component of economic regeneration and urban renewal [33], which helps it receive investment and a legal protection from the UK government. However, UK's built heritage is ferociously defended by a group of powerful NGOs. A number of integrated policy frameworks developed by either the government or NGOs dealing with energy efficiency improvements in heritage buildings are as follows:


improvements (both in planning and implementation stage) of heritage buildings (built before 1919), buildings listed in a conservation area, or older buildings. Most importantly, these technical advices advocate the Whole House Retrofit approach. Historic England supports the government's efforts on improving the energy efficiency of existing buildings through Part L of the Building Regulations, which makes it clear that "*a reasonable compromise on the energy e*ffi*ciency targets may be acceptable in order to preserve character and appearance and to avoid technical risks*". They do this by specifically including some 'exemptions' where 'special considerations' apply for historic buildings and those of traditional construction.


#### *3.4. Incentives for Energy Retrofitting of Built Heritage in the UK*

Heritage tourism sector is an important part of the UK economy for both domestic, and international visitors, with the purpose of visiting historic towns. In the 2019 report of the Nations' Brand Index Survey of 50 nations, in which nations are ranked upon their universal reputation, UK was ranked fourth for criteria including 'rich in historic buildings and monuments' [39]. To own a historical building or to live in a city rich in these buildings is indicative of a high socio-economic status. Both prestige, cultural and economic incentives to invest in ongoing maintenance and repair are common contexts for retrofit of historic buildings rather than a desire to reduce energy costs alone [40,41]. This is proved in the annual report by the Centre for Economics and Business Research on behalf of Historic England, examining the links between organisations in the heritage sector and the local economies. The study claims that keeping the historic/cultural properties in active use as businesses, homes, tourism attractions or a combination of all three helps to stimulate environmental, economic and community regeneration [42]. This is also addressed by the planning policy guidance by Historic England [43], which enables development of a significant place (e.g., a historic building) to ensure it remains in continued use whilst minimising damage to its heritage value.

One of the outstanding driving forces behind energy retrofitting of heritage buildings is climate change. The frequency, intensity and duration of heatwaves are projected to increase worldwide, including in the UK. All the UK regions are projected to become warmer, especially in summer [44]. While at the time of writing this article the heating demand remains the main energy use driver in buildings, it is estimated that, even today, 20% of the UK housing stock suffer from overheating

during summer [45], which will lead to an increased energy use due to rising cooling demands [46]. Consequently, this has led to a substantial interest in policy and research towards reducing indoor overheating risk in UK homes and integrated retrofit designs encompassing both adaptation and mitigation strategies [47].

#### *3.5. Constraints for Energy Retrofitting of Built Heritage in the UK*

A result of the high socio-economic value of heritage in the UK is the proliferation of several civil agencies and organisations, involved in conservation activities. Grant funding is provided through these organisations for maintenance, repair, and upgrading of historic buildings, and due to variations in sizes and operation mode of these organisations, the advice and guidance they provide on various matters are not always compatible [48]. This leads to the emergence of fragmented retrofit approaches in local policies. Particularly, the planning approvals needed to be sought for interventions on historic buildings defined by independent local planning authorities can substantially neglect technical innovations on energy efficiency. For example, in the case of listed buildings' applications for double glazing, there is no consistent approach across the country. Some Councils rigidly insist on authentic material regardless of the energy performance of the building, while some allow it [49]. Historic England's recent report [50] suggests in the case of steel windows or window frames capable of carrying double glazed units, their addition to existing windows may be considered acceptable. A similar conflict was reported by [51] with regards to the use of slim profile double glazing (SPDG) for the energy efficiency retrofit of historic buildings.

The potential conflict between energy reduction and conservation of heritage values in local policies is also observed in case of unlisted historic buildings. In a study by [52] carried out in Cambridge, a town which had a boost of energy efficient retrofits following the introduction of the Green Deal Communities Fund, the application of measures incompatible with the historic neighbourhood is criticised. According to this fund, for unlisted historic buildings the use of external wall insulation, which may substantially change the appearance, was indicated as a 'permitted development'. In this way, in the planning application for retrofitting unlisted historical buildings, the decision on prioritising heritage or energy values is completely left to the subjective knowledge of local officers. A similar conflict between different local authorities is also observed in the North of England as shown by the findings of a survey composed of 48 participants (comprising practitioners and local officers), pointing out challenges and conflicts between housing and planning officers over the planning permission for external wall insulation [53].

#### *3.6. Turkey's Legal and Administrative Policies on Improving Energy Performance of Buildings: A Chronological Review*

Turkey has set forward comprehensive policy packages over buildings' energy demand for the last two decades. Among the important policies currently in effect are Energy Efficiency Law (2007), Buildings' Energy Performance Regulation (2008), Buildings' Energy Efficiency Regulation (2011), Energy Efficiency Strategy (2012), TS 825 (2008), National Energy Efficiency Action Plan (2018), and the Green Buildings Regulation (2017). The legislative background on improving energy performance of buildings is discussed within two distinct periods in Turkey: during 1970–2000 and during the period from 2000 until present.

Similarly, to the UK, Turkey was not exempted from the results of the energy crisis of the 1970s. The first Turkish Thermal Insulation Standard (TS 825) was developed in 1970 [54]. The first application of thermal insulation in buildings started using imported external insulation materials in 1991, when double glazing units also began to be used in window frames [55]. In 1992, in spite of Turkey's membership in the OECD, Turkey did not sign the UN Framework Convention on Climate Change when it was adopted in 1992, nor has it made emissions reduction commitments under the Kyoto Protocol. The reason was the fact that Turkey's per capita CO<sup>2</sup> emissions were lower than OECD norms at that time [56]. In 1999, a new version of TS 825 was published [57] and after 30 years it was "recommended"; its use became mandatory as of 2000, though only for new buildings, to define the maximum allowable heat losses and calculate heating requirements. The Thermal Insulation in Buildings Regulation (2000) is considered to be the first main regulation dealing with building energy performance in Turkey. In 2007, Turkey adopted The Energy Efficiency Law [9], whose main objectives included increasing energy efficiency, reducing environmental impacts, and reducing the load of energy costs on the economy. There are a number of policy measures outlined in the legislation to be implemented on the built environment related to the sustainable architectural design and green buildings. For the first time, through this legislation, increasing public awareness has come to the forefront of energy efficiency activities. The revised version of TS 825 issued in 2008 extended its scope to also existing buildings with emphasis on dwellings [58]. Although TS 825-2008 is still the mandatory standard, it overlooks cooling energy requirements and heat store capacity [59]. In accordance with European Union's Framework Directive 2002/91/EC and Energy Efficiency Law (No. 5627), Buildings' Energy Performance Regulation (BEP TR) [60] was published in 2008, targeted at both new and existing buildings. The Ministry of Environment and Urbanization defines the objectives of BEP TR as (1) increasing efficient use of energy and applicability of renewable energy systems in buildings, (2) reducing greenhouse gas emissions, and (3) determining performance criteria and application principles in buildings and environmental protection activities. The energy identity certificate for both new and existing buildings is issued based on this regulation.

Important strategy documents for energy efficiency policies have been put forward in recent years in Turkey including Urban Development Strategy Plan 2010–2023 [61], Climate Change Strategy Plan 2010–2020 [62], and Energy Efficiency Strategy Document 2012–2023 [63]. Medium-term targets encouraging applicable energy retrofitting strategies for existing buildings, such as the Energy Identity Certificate by implementation of thermal insulation, are addressed in Climate Change Strategy Plan [62]. In 2011, Buildings' Energy Efficiency Regulation, issued by the Ministry of Energy and Natural Resources [MENR], covering applicable technical measures on improving the efficiency of heating, cooling and lighting systems for both new and existing buildings [64]. Green Building Regulation issued in 2014 by the Ministry of Environment and Urbanization with the aim of evaluating the sustainability of new and existing buildings and settlements in terms of their environmental, social, and economical performances. Very recently, Turkey's government has set up a series of energy efficiency goals and policy frameworks to achieve the 2023 Energy Efficiency targets in the scope of the EU accession negotiations. The National Energy Efficiency Action Plan [10], is one of them that represents a concrete energy efficiency strategy in the building sector in terms of both technology and investment. Decreasing primary energy use in Turkey by 14% in 2023 has been set as its main objective. Although the NEEAP's actions comprise a broad set of domains containing technology, finance and policy, it suggests the use of the existing policy instruments for their implementation, which begs the question of whether these will be sufficient or not.

Turkey's energy efficiency policies are carried out under the responsibility of the MENR and its branches, like the General Directorate of Renewable Energy. The department supports the investments on efficiency improvement in the industrial sector in accordance with the framework of Energy Efficiency Law. The Ministry of Environment and Urbanization is the other governmental body with substantial responsibilities regarding energy efficiency in new and existing buildings, and settlements. National strategies are developed by the Energy Efficiency Coordination Board as mandated by Energy Efficiency Law.

#### *3.7. Turkey's Legal and Administrative Policies on Built Heritage Conservation: Chronological Review*

Legal and administrative basis of conservation activities in Turkey dates back to the Ottoman Era, with the enforcement of the Ancient Monuments Regulation (AMR) in 1869. While initially the AMR focused on the archaeological remains and findings, it was amended in 1874, 1884 and 1906 to extend the definition and the scope of 'monuments'. The AMRs were followed by the Conservation of Monuments Regulation (CMR), issued in 1912, in which the permissible interventions on the historic monuments were defined in more detail [65–67]. In accordance with the AMR and CMR, measures and interventions regarding the historic monuments, archaeological excavations, findings and museums were managed by the Ancient Monument Conservation Council (AMCC) established in 1917.

After the foundation of the Turkish Republic in 1923, AMCC, which was later on revised as the Council of Conservation of Ancient Monuments, remained as the main authorised body for decision-making and controlling the interventions to historic buildings until the establishment of the High Council for the Historical Real Estate and Monuments in 1951 [65]. Similarly, AMR and CMR, continued to be the main legal instruments concerning the conservation of historic buildings during the Turkish Republican Era, until the acceptance of the Antiquities Law (No: 1710) in 1973. Different from the previous regulations, this law brought the concept of 'conservation site' setting up the legal basis for area based conservation, not only focusing on the historic monuments but also dealing with the conservation of historic tissues and more modest historic buildings. Accordingly, the High Council's authority was extended to cover decisions not only for individual monuments, but also to conservation areas.

Antiquities Law (No: 1710) remained in act for 10 years, until the acceptance of the Law for the Conservation of Natural and Cultural Properties (No: 2863) in 1983 [68], which is still in act together with some later amendments. This new law; offers a detailed classification of cultural properties and conservation sites in different conservation statuses and degrees, while explaining their registration, documentation, project preparation, decision-making, intervention and control processes. In addition to these, together with this law, decentralisation of the decision-making process was attempted by redefining the authorised bodies in the decision making process as the Regional Councils for Conservation of Cultural and Natural Heritage and High Council for Conservation of Cultural and Natural Heritage. Amendment of the Law for the Conservation of Natural and Cultural Properties (No: 2863) in 2005 with the Law No: 5226, even increased the ongoing decentralisation process by enhancing the roles and responsibilities of the local authorities.

In Turkey, according to the Law No: 2863, historically or culturally important immovable properties built until the end of the 19th century, as well as the ones having special values although built after the 19th century, are in the category of 'cultural properties'. Currently the identification of cultural properties and determining their registration degrees and statuses are the responsibility of the General Directorate of Cultural Properties and Museums, a division of the Ministry of Culture and Tourism. Historic buildings and structures are listed in the national registry either as a cultural property, or as part of larger areas designated as conservation sites, or both. The vast majority of conservation areas and registered historic buildings in the country are first identified as historically or culturally important by the Government and listed in the national registry. Once they are registered, they are made distinct from other immovable property and development rights are restricted. Moreover, whether the property is private or not, a registered building acquires the status of public good, meaning that the owner's freedom to intervene is firmly restricted. All kinds of actions and interventions related with the registered buildings and sites are subject to the approval of the Regional Conservation Council.

#### *3.8. Potential Incentives for Energy Retrofitting of Built Heritage in Turkey*

According to the statistics released by the General Directorate of Cultural Properties and Museums, by the end of 2019 [69], there were 113,137 registered cultural properties in Turkey. Moreover, there are 460 registered conservation sites having historic urban/rural tissues composed of a vast number of historic buildings. When combined with unregistered historic buildings, this number rises to a substantial portion of building stock. On the other hand, according to the Ministry of Tourism and the Statistics Institute, visiting historical sites and buildings is ranked second most commonly reported purpose of foreign tourists visiting Turkey. In the latest report of Future Brand Country 2019 Index [70], Turkey is ranked 4th for the 'Heritage and Culture' criteria among 75 countries, surveyed in terms of their potential in Heritage, Culture and Tourism. This shows that following the footsteps of the UK,

which has been successful at capitalizing on its historical buildings, Turkey's rich built heritage has also the potential of defining it as a tourism destination.

With regard to the climate change crisis, like the UK, Turkey's building stock is expected to face warmer climatic conditions in the near future, which is another factor increasing the vulnerability of the country's built heritage. Accordingly, IEA [3] urges the government to set a longer-term energy policy agenda for 2030. As a response, The Turkish National Energy Efficiency Action Plan [10] set a strategic goal towards 'low building energy demand and carbon emissions; scale up sustainable, environment-friendly buildings', further highlighting the need for developing energy retrofitting policies covering efficient cooling standards, specifically, for historic houses. Even in the case of existing buildings, Turkey's policy framework suffers from the lack of concrete minimum standards for efficient cooling, which becomes critical in terms of energy use and comfort as the cooling demands increase in parallel with overheating climatic conditions. This need can be transformed to a potential incentive for developing adaptation and mitigation retrofit measures towards a climate-resilient built heritage stock.

#### *3.9. Constraints for Energy Retrofitting of Built Heritage in Turkey*

As previously mentioned, the European energy efficiency directives exclude historic buildings from implementation of energy-efficient retrofit measures. This translates into Turkey's attempts to upgrade its legislations in alignment with the EU, making the position of built heritage in the greater scheme of energy efficiency rather uncertain. Moreover, the meaning and scope of the term "retrofit" is vague in Turkish regulations, and it is merely mentioned even in the latest reports and action plans i.e., Green Buildings Regulation (2017), without any definitive explanation.

In Turkey, if a historic building is deemed to attain particular cultural/historical values it is placed completely under the responsibility of the Ministry of Culture and Tourism and the energy efficiency regulations defined for existing buildings by the Ministry of Environment and Urbanization do not apply. Unfortunately, there is no legal and collaborative action between sectors responsible for heritage protection and energy efficiency of buildings in Turkey.

Another challenge in Turkey's built heritage subsector is that a substantial portion of the registered immovable cultural heritage belongs to the historic houses (known as civil architecture) [69]. The residents of these dwellings in Turkey suffer seriously from, in cases of buildings with listed status, the prohibition of development rights on the properties, and in general, the costly burden of the repair, maintenance and restoration of their homes. This is particularly alarming in the case of heritage houses owned by lower-middle income and low-income people, which are mostly left to their fate.

A summary of incentives and constraints for the UK and Turkey with reference to the national and international legislation, as well as the role of NGO's and other financial drivers in the development of guidance directed at the energy-efficient retrofitting of heritage buildings is given in Table 1.


**Table 1.** Comparative synthesis on energy retrofitting of historic buildings in the UK and Turkey.


#### **4. Comparative Analysis of the UK's and Turkey's Regulatory Approaches on Energy-E**ffi**cient Retrofitting of Built Heritage**

In this study, the policy frameworks regarding 'energy efficiency in buildings' and 'built heritage', which are currently in place in the UK and Turkey, have been thoroughly reviewed. A comparative

analysis of these frameworks was conducted with the aim of discussing the level of integration between energy and built heritage policies and identifying existing gaps in legislation and organisational structure to make these viable. The conclusions drawn from this comparison are summarised below.

With regard to the evolution of UK's regulatory approaches on energy-efficient retrofitting of built heritage, 2008 can be set as a benchmark date, when the first guide [71] to improve energy efficiency in historic homes was published as the result of a project titled, "Energy Heritage" carried out in Edinburgh. It has become quite clear that in the UK since 2008 until the present, several studies, projects, workshops, technical reports and guidance plans, encompassing all the three levels of policy frameworks were published (Figure 1). Whilst, in Turkey, except for the published one handbook and one workshop under the scheme of 'Energy Efficiency for Historic Buildings' led by the Association for the Protection of Cultural Heritage (APCH) [72], no other technical reports and guidelines have been published, neither under the responsibility of public governmental bodies, nor by NGOs.



**Figure 1.** Comparison of the level of policy frameworks on energy efficiency in historic buildings

It can be seen that Turkey uses a predominantly informative and voluntary scheme (third level of policy framework in Figure 1) to approach the energy retrofit of the heritage building stock, which still needs to be improved in other domains of this level, for example through awareness-raising campaigns, competitions, and courses, as there are several examples from the UK, e.g., those run by the STBA, including the "Retrofitting Traditional Buildings" and "Energy Efficiency Measures for Older and Traditional Buildings" courses. As discussed in Section 3.9, since the scope of the term "retrofit" is vague and does not refer to a technically established content in Turkish regulations, firstly, an increased public and industry awareness should be developed through technical training events and courses aimed at communities and practitioners, introducing the general concept of retrofit and viable measures for improving energy performance of historic buildings.

Secondly, in the UK context, the retrofit approaches are substantially streamlined towards climate change mitigation and adaptation schemes, and aimed at making the indoor environments more resilient to heat waves [73,74], while the most common retrofitting measures, such as increased insulation and airtightness may lead to higher levels of indoor pollutants and condensation problems. This becomes more critical in the case of historic/traditionally constructed buildings whose semi-permeable fabrics keep the internal moisture and temperature in balance with the ever varying outdoor hygrothermal conditions [75]. This issue is well-addressed in PAS 2035, now in force in the UK, requiring management of moisture balance and upgrading of ventilation when insulation is installed, to reduce condensation and mould risks. On the other hand, in order to minimise the potential unintended consequences of energy retrofit measures for historic buildings, which are becoming more and more apparent [74], one of the primary concerns of both owners and policy makers should be applying regular maintenance and repair prior to retrofit, which, in the UK case, is a requirement of the PAS 2035 [38]. Therefore, Turkey should pay utmost attention to integrate measures in its policies so as not to disrupt the buildings' moisture balance irreversibly by making it mandatory to (a) repair prior to retrofit, (b) ensure a good management of moisture balance, and (c) upgrade ventilation when insulation is installed.

It is noteworthy that in addition to the projected strong heat waves as one of the results of the climate change crisis, both countries still face the problem of fuel poverty insomuch that of the total energy used by the average UK home, almost 80% was used for heating and hot water demands [76]. The number of households in fuel poverty is estimated to be approximately 10.9% of all English households [77,78]. In the case of Turkey, about one quarter of households are energy-poor and about half of the lowest income households face the problem of fuel-poverty [79]. In this regard, the number of standards and regulations for efficient heating in residential buildings in the UK and Turkey is considerable compared to efficient cooling standards. Although it is observed that the ratio of energy-poor households is decreasing in both countries, an efficient heating problem still is a challenging issue for both cases.

Thirdly, in the UK, cross-sector institutional relationships have been fitted well through the collaborative research and projects carried out between non-profit (governmental/non-governmental) organisations to help policy agencies to understand and enforce the requirements of the energy performance of historic buildings. As an example, in 2011, STBA's first research work on analysis of the gaps in the performance of UK's traditional buildings was funded by Construction Skills and English Heritage, which are two different organisations; the former linked to the Department for Communities and Local Government, and the latter, a charity managing the National Heritage Collection. However, in Turkey, the establishment of NGOs active in the field of conservation of heritage buildings, is much delayed compared to the UK. Two important early examples of these are Vehbi Koç Foundation (1969) and the Sabancı Foundation (VaKSa, 1974), while others were mostly founded in the 1990s [67]. In contrast to the UK, where several technical reports and guidance are published either by non-departmental Governmental bodies (e.g., Historic England) or NGOs (e.g., STBA), none of the NGOs in Turkey proposed, led or developed guidelines towards improving energy efficiency in heritage buildings, and their engagement with the Governmental efforts towards energy efficiency of heritage buildings should be further encouraged. In addition, individual governmental bodies responsible for energy efficiency and heritage conservation should be brought together through cross-sector regulations to address this cross-disciplinary problem jointly.

Fourthly, as discussed previously, UK's planning policy guidance [43] secures the long-term future of historic buildings through "its continued use for a sympathetic purpose", while minimising damage to its heritage values. Turkey's regulations also encourage putting protected cultural properties in continued use, in line with the functions prescribed by the Regional Conservation Councils. Users of such properties are currently obliged to maintain, repair and restore them in line with the principles of Law no. 2863. However, Turkey needs to produce official statistical data as to the active use and maintenance status of, especially, unlisted heritage dwellings, as this is currently nonexistent.

Fifthly, as discussed in Section 3.5, the lack of a clear conservation framework in retrofitting practices leads to a strong inconsistency between independent local planning authorities in their promoted advice and guidance, including the listed buildings consent applications for double glazing or in the use of external wall insulation in unlisted historic buildings. In fact, the UK heritage building sector appears to be over-legalised with many organisations and policy frameworks managing the field. In this regard, a less-is-more approach could have a positive impact by bringing unity and transparency to the practice within the heritage building sector in the UK both when it comes to preserving their heritage values and implementing energy efficiency measures.

Finally, although it is clear that the UK has a better developed policy framework for the energy retrofit of heritage buildings, robust data regarding the actual numbers of the retrofitted heritage building stocks with reference to measurable, concrete effects resulting from, and a critique of the existing policy frameworks, do not exist in either country. All stakeholders of the energy efficiency of heritage buildings should therefore jointly work towards creating this information for a thorough appraisal of the efficiency and viability of their policy framework and practice in the mid- and long-term.

#### **5. Is Policy Enough?**

The decision as to whether and how to retrofit heritage buildings for an enhanced energy performance should be informed, among other factors, by original building fabric and construction technology characteristics. A detailed understanding is needed as to how much gain in energy performance is possible by restoring the fabric through repair, and by actually retrofitting it, and therefore life-cycle analysis remains to be one of the most powerful tools for researchers. In any case, strengthening conservation processes of listed and unlisted built heritage through encouraging constant use, and not only allowing but also developing incentives to carry out regular maintenance in accordance with the original fabric characteristics to ensure these buildings are in a better condition is extremely important to close the energy efficiency gap between actual and targeted performances; this should be achieved through simple elemental interventions which have been shown to demonstrate a higher cost-to-benefit advantage [80], and hence to make some retrofitting measures redundant. In this respect, enhanced public awareness is, again, a critical factor to ensure that the policies fulfil their goals.

Historic buildings are commonly labelled as problematic for being 'draughty', 'leaky', and 'inefficient'. However, these buildings often offer a lot to be learned regarding contextual design, and use of architectural and structural detailing in effective ways to tackle the microclimatic conditions they are exposed to, and hence their poor performance may be owed to age, lack of maintenance, change of lifestyle and resident profile, rather than their intrinsic constructive features. Therefore, energy retrofitting of these structures, as a very case/context-specific issue, requires a deep understanding of their original fabric characteristics, as well as the society and community it is valuable for. People's perception of the 'history' and 'heritage', in fact, shapes their perception of 'acceptable changes' and the value of the heritage buildings [5]. That is why despite all the arguments on the alignment of legislation and guidance related to energy retrofitting of heritage buildings, decision-making in this arena still requires case/context-specific assessments and a case-by-case approach as in all interventions on heritage buildings.

#### **6. Conclusions**

More efficient energy use in buildings continues to be one of the most valuable untapped potential resources. The constraints to accessing this untapped resource, especially in historic buildings, are numerous and complex, but can be overcome through raising awareness and developing appropriate policies. To achieve this, it is important to draw lessons from convincing examples that demonstrate various possibilities. In a world struggling to confront climate change, a holistic and synergistic approach for improving the energy efficiency of all buildings needs to be a priority. Even though the regulations for buildings exempt most listed heritage buildings from energy performance improvements, many of these buildings can and should be able to accommodate some improvements through options available for long-term sustainability that are compatible with their heritage values.

The UK's current policy framework supports improving energy efficiency of heritage buildings, aiming at combining energy efficiency goals with heritage values. The establishment of such a decision-making system requires knowledge of both building physics and heritage values, and should have financial support and expertise from governmental bodies or NGOs. This begs the need for a strong cross-sector and multi-stakeholder collaboration involving both arenas of built heritage management and energy efficiency in buildings. Last but not least, we believe that the energy retrofitting of historic buildings should be country, even region specific. Accordingly, policy frameworks should be shaped accounting for the socio-economic and cultural backdrops in any given context. Planned policies in this respect need to be promoted through a range of economic incentive programmes and public awareness campaigns as auxiliary means, without which they will fail despite their technical and organisational merits.

**Author Contributions:** N.J., A.G.B.A.; conceptualisation and methodology. N.J.; investigation. N.J., Y.D.A.; formal analysis. A.G.B.A., Y.D.A., P.R.; provided resources. N.J.; writing-original draft. N.J., Y.D.A., A.G.B.A., P.R.; writing-review and editing. A.G.B.A., Y.D.A., P.R.; funding acquisition. All authors have read and agreed to the published version of the manuscript.

**Funding:** This study has been carried out as part of the "PROcesses for sustainable retrofit of Traditional dwellings in Turkey for Climate-resilience, Conservation and ComforT (PROT3CT)" project jointly funded by British Council (no. 527666821, funding Y.D.A and P.R.) and TUBITAK (no. 119N514, funding N.J. and A.G.B.A.) through Newton Funds Institutional Links and of "Tales of cold and draft: Establishing retrofit needs of Turkish vernacular architecture for energy-efficiency, comfort and conservation" funded by 2019–2020 UCL Small Grants Grand Challenges scheme. The APC was funded by the UCL Open Access Office. The authors are grateful to all funders.

**Conflicts of Interest:** The authors declare no conflict of interest. The funders had no role in the design of the study; in the collection, analyses, or interpretation of data; in the writing of the manuscript, or in the decision to publish the results.

## **References**


80. Jones, P.; Lannon, S.; Patterson, J. Retrofitting existing housing: How far, how much? *Build. Res. Inf.* **2013**, *41*, 532–550. [CrossRef]

© 2020 by the authors. Licensee MDPI, Basel, Switzerland. This article is an open access article distributed under the terms and conditions of the Creative Commons Attribution (CC BY) license (http://creativecommons.org/licenses/by/4.0/).
