Sustainability and universal design aspects in heritage building refurbishment

Abstract

Purpose

The purpose of the paper is to provide a comprehensive overview of the refurbishment of heritage buildings with special emphasis on sustainability and universal design. Findings of the study are the basis for further research and development of enhanced strategies for retrofitting and adaptive reuse of heritage buildings in the framework of sustainability and universal design.

Design/methodology/approach

The present research focusses on literature review analysis of specific elements of the refurbishment of heritage buildings with the aim to discover the characteristics/indicators of sustainability and universal design, which are usually used in refurbishment project and the gaps. In this paper, the latest state-of-art in the mentioned fields has been assessed, and the developments along with research gaps and potential future research focusses have been identified. The literature was collected mainly through Science Direct, World Wide Science and Emerald, especially focussed on publications from 2000 to 2019 written in English and the Web for regulatory and recommendation publications. Other sources, such as actual projects, might shed additional light on the specific issues of the studied topics.

Findings

This review shows that the current research related to heritage building renovation and reuse does not address sustainability and universal design issues comprehensively. Typically, in research, the topics of heritage, sustainability and inclusiveness are considered separately. In real situations, however, they are interconnected and influence each other, forming an indivisible whole. The needs of persons with disabilities (PWD) in correlation to the built heritage are not well studied. This is why it is important to consider these topics not only separately but also in an interrelated way.

Research limitations/implications

The need for cross-disciplinary problem-solving method, based on a holistic approach, to form the base for implementation of universal design principles into refurbishing of heritage buildings is seen.

Practical implications

This paper demonstrates the need for usable procedures for various stakeholders in their everyday practice.

Originality/value

The combined subjects of sustainability, heritage buildings and universal design are not well covered by research. Lack of appropriate literature for this specific area is forming a significant gap that hinders the development of relevant information and methods that could be applied in actual projects. This paper, albeit in a partial way, intends to fill this gap and opts to provide a comprehensive summary of the sustainability factors affecting adaptive reuse of heritage buildings with special emphasis on users, specifically PWD.

Citation

Kristl, Ž., Temeljotov Salaj, A. and Roumboutsos, A. (2020), "Sustainability and universal design aspects in heritage building refurbishment", Facilities, Vol. 38 No. 9/10, pp. 599-623. https://doi.org/10.1108/F-07-2018-0081

Introduction

Historic and heritage buildings form a substantial part of the building stock all over the world. Their preservation is of paramount importance for social, economic and environmental reasons (Franzoni et al., 2018), forming the basis for sustainable development. Many times they also present a significant share of residential and public buildings, which play an important part in everyday life of the occupants. As such, they have to be accessible to all groups of population and have to offer equal opportunities to accommodate various activities.

The key element of heritage buildings is the quality of design, which is the primary reason of their listed status. “Protection” includes preservation of the architectural elements, space and materials of the original buildings. In many cases, heritage buildings are well-preserved and presented to public in their original form (Maraveas and Tasiouli, 2015) or provided for economically viable reuse (Tam et al., 2016). In other cases, however, communities are facing the challenge of what to do with obsolete buildings and sometimes the wider areas. Revitalization through adaptive reuse is considered to be a favourable option, with many buildings being adapted to other uses (Ren et al., 2014; Misirlisoy and Gunce, 2016; Fernandez-Fernandez et al., 2017). However, balancing the requirements of cultural heritage and development is indeed a challenging task. In the face of growing environmental issues, the principles of sustainability and inclusiveness need to be carefully considered and incorporated into the overall urban system.

Typically, the topics of heritage, sustainability and universal design are considered separately or in conjunction with related topics (Petković-Grozdanovića et al., 2016; Bullen and Love, 2010; Blecich et al., 2016). Although it could be assumed that both heritage protection and universal design are already contained within the general concept of sustainability, this idea is too general for practical use. Probably this is one of the reasons why in legislation, (although the part of the same system) sustainability and accessibility are treated as two distinct requirements (CPR 305, 2011), and built heritage is established as a completely separate regulative area. Similar division can also be observed in literature, where these areas are mostly dealt with separately. In real situations, however, they are interconnected and influence each other, forming an indivisible whole. This is why it is important to consider these topics not only separately but also in an interrelated way.

In the existing literature, the combined subjects of sustainability, heritage buildings and universal design are not well covered by research. Lack of appropriate literature for this specific area is forming a significant gap that hinders the development of relevant information and methods that could be applied in actual projects (e.g. in government agencies or private sector heritage building refurbishment). This paper, albeit in a limited way, intends to fill this gap and opts to provide a comprehensive summary of the sustainability factors affecting adaptive reuse of heritage buildings with special emphasis on users, specifically persons with disabilities (PWD).

Based on the general problem description, the research questions this paper proposes are as follows:

RQ1.

Which topics of sustainability and universal design in heritage projects are covered in literature?

RQ2.

Which challenges related to universal design are foreseen?

The article is organized as follows. Part one explains the importance of sustainability and universal design in heritage refurbishment projects; Part two introduces the research methodology; Part three focusses on the results of the review, answering the first and second research questions; and Part four summarizes the review.

Theoretical framework

Importance of universal design

Universal design also named inclusive design is defined as “a process that enables and empowers a diverse population by improving human performance, health and wellness, and social participation” (Steinfeld and Maisel, 2012). In the field of the built environment, the seven principles of inclusive design are defined to promote universal accessibility (Yiing et al., 2013). Universal design offers provision and accommodation for a wide variety of users, from young children to the frail older adults, including PWD. According to Kadir and Jamaludin (2013), inclusive environment with universal design features is more cost efficient than specialized barrier-free design, because it has a broader scope of accessibility and user-friendliness.

At the institutional level, there are a number of documents that support inclusive design. The most important is the UN Convention on the rights of PWD (CRPD, 2006) which bounds the signatories to facilitate accessibility to buildings and other facilities open to the public. In EU, accessibility is considered a precondition for the participation of PWD in society and in the economy (COM 636, 2010; EIDD, 2004). The accessibility is introduced into the legal system that regulates the built environment (CPR 305, 2011). Also, the Commission has developed disability-related, EU-level indicators linked to the Europe 2020 targets for employment, education and poverty reduction to closely monitor the situation of PWD in the Member States and at EU level. These indicators show a clear gap with the rest of the population (SWD, 2017), which is a sign that the transfer of the inclusiveness principles from institutional to practical level has not been completed.

The overall aim of universal design and accessibility principles is to ensure accessibility to goods and services for everyone, including PWD. This can be achieved through the prevention, identification and elimination of barriers faced by PWD in a number of key areas such as the built environment, transport, and information and communication (SWD, 2017). The governments are aware of the fact that many citizens live with some form of disability which ranges from mild to severe. Globally, WHO (2011) estimates that in 2011, more than one billion people had some form of disability. This is because of the ageing of populations and the higher risk of disability among elderly population as well as the global increase in chronic health conditions. Similarly, in the EU, one in six people has a disability. That number is expected to rise, as the EU’s population rapidly ages (COM 636, 2010). It is expected that, by 2020, approximately 120 million Europeans will have a disability. The share of women with disabilities in the overall population is higher than that of men (29.5 vs 24.5 per cent) (SWD, 2017). The Commission proposes to use legislative (CPR 305, 2011) and other instruments, to optimise the accessibility of the built environment (COM 636, 2010). National governmental documents support universal design in the built environment including the built heritage (MLFSAEORS, 2014); however, many constraints linked to building structure, space limitations and preservation requirements reduce the quality of solutions. For this reason, COM 636 (2010) note that much of the built environment is still not accessible enough.

Importance of heritage

The importance of the built heritage is endorsed by numerous national, supranational and international institutions and defined in several documents (UNESCO, 2011; ICOMOS, 2011; Europa Nostra, 2009; COM 445, 2014; COM 477, 2014; MIRS, 2016; TEK17, 2017). It is commonly agreed that heritage buildings are vital in terms of transferring cultural identity and historical memory of the space to the next generations (Misirlisoy and Gunce, 2016). Some authors also claim that built structures reach beyond their physical realm, also preserving urban landscapes related to emotional safety, attachment, identity and community spirit (Sutestad and Mosler, 2015). Today, built heritage is also presented as a part of building stock, which often has considerably inferior energy performance (Troi, 2011; EC Energy, 2017), and is many times less accessible. Therefore, refurbishment of heritage buildings is inevitably an important task that includes consideration of many aspects, such as cultural, physical, digital, environmental, human and social (COM 477 2014), including questions of inclusive and cohesive society.

Ornelas et al. (2016), yet, argue that inadequacy and incompatibility of actual codes’ requirements in relation to the particular constructive, architectural and material characteristics of the built heritage present a major obstacle for retrofitting of heritage buildings. They further suggest a holistic methodology that ensures maximum preservation of built heritage through minimum, but sustained interventions. As can be understood, modern conservation concepts use a holistic approach, preserving not only technical and architectural heritage of the locality of a particular building but rather, as Versaci (2016) points out, a heritage landscape comprising built and natural environment. Many authors emphasize that especially industrial buildings with their large volumes can be easily adapted to other uses, e.g. to public spaces. Romeo et al. (2015) find that it is possible to identify industrial heritage features that meet the increasing demand for architectural and urban spaces intended for cultural and social needs. However, it is particularly important to analyse factors affecting adaptive reuse decision-making and to develop a holistic model for adaptive reuse strategies for heritage buildings (Misirlisoy and Gunce, 2016). Stendebakken et al. (2015), for instance, identify nine evaluation aspects and propose a framework for assessment of the potential new uses for cultural heritage places. The proposed framework serves as a tool for understanding the value of spaces for historic buildings. The model can include various evaluation factors such as project management, architectural and cultural heritage management (Stendebakken et al., 2015). Furthermore, heritage conservation in urban renewal has an important social role, having significant impact on enhancing a community’s sense of place, identity and development (Yung et al., 2017).

Importance of sustainability

Sustainability rests on three basic pillars, environment, economy and society, which all form part of circular economy approach (COM 614, 2015). In the recent years it has been suggested that the additional pillar representing institutions should be added to the three existing sustainability pillars (Valentin and Spangenberg, 2000). Institutions as sustainability pillar have been mentioned for the first time by the UN Commission on sustainable development (CSD, 1995). They are defined in terms of the interpersonal process, such as communication and cooperation, which result in a system of rules that guide the interaction of members of a society (Spangenberg, 2002a). Indicators for the evaluation of institutional sustainability are, for example, a non-discriminatory setting, social security systems, equality rules, etc. (Ameen et al., 2015; Spangenberg, 2002a, 2002b,). Those issues are very important when considering inclusiveness and accessibility for vulnerable groups of society, including PWD. The definition of sustainability in practice has not yet been finally and explicitly defined. Lele (2013) discusses what sustainable development meant when it was first defined and how the changing circumstances require to reconsider it again. He suggests that sustainable development should be redefined as an “ecologically sustainable and socially just effort to achieve basic material and non-material well-being” (Lele, 2013). In terms of space and with the global population becoming increasingly urbanized, cities inclusiveness, safety, resilience and sustainability above all encompass adequate residence and general accessibility of open public spaces (UN, 2019). Sustainability in the field of built environment can also be regarded as a continuously evolving concept, which rests on complex system of sustainable building practice (Doan et al., 2017). Indicators of sustainable building are currently not yet fully established and unified. One of the emerging systems is a common EU framework of core sustainability indicators for office and residential buildings Level(s). It facilitates metrics for measuring the environmental performance of buildings during their life cycle as well as their environmental performance, user health and comfort, life cycle cost and future performance risks (Dodd et al., 2017).

Still, the research on the topics of sustainability and heritage buildings is focussing mainly on energy efficiency, which reflects in a large number of articles. Martinez-Molina et al. (2016), Yung and Chan (2012) and Fabbri (2013) published a comprehensive reviews aiming at energy efficiency and thermal comfort in various types of heritage buildings, and Munarim and Ghisi (2016) address the topic of environmental impacts linked to heritage building rehabilitation. Vieites et al. (2015) present seven EU funded projects, dealing mainly with integration of innovative technologies and use of various sources of renewable energy in existing buildings, some of them targeting at historic buildings. Martinez-Molina et al. (2016) further find that energy retrofitting of heritage buildings to current standards is essential for improving sustainability. In this context, Azizi et al. (2016) identify 46 issues that hinder historic building conservation and classify them into five groups of technical, environmental, organizational, financial and human issues. The most important problems are linked to technical matters, including lack of resources and skilled workforce.

Still, as pointed out by Lidelöw et al. (2019), there is no overview of how energy efficiency and heritage conservation have been approached in the studies. To address this gap, they categorize and assess the identified studies in terms of two key elements, e.g. energy analysis and analysis of cultural heritage values. They find that most of the studies evaluate and propose measures to reduce the operational energy use of single heritage buildings, and fewer have applied a broader system perspective. Moreover, the underlying notion of the buildings’ cultural heritage values seems to have been derived mainly from international conventions and agreements, while potentially significant architectural, cultural and historical factors have been rarely discussed. It can be assumed that this is a logical consequence of the fact that technical and physical factors are measurable and can be straightforwardly defined and analysed, while cultural and heritage aspects are less tangible. More comprehensive approaches including several sustainability factors are rarely presented. Among the few that can be mentioned are the studies by Franco et al. (2015) that suggest a preliminary approach and general criteria for the building refurbishment in relation to the architectural and historical commitments, and Misirlisoy and Gunce (2016) that propose a holistic approach to adaptive reuse strategies for heritage buildings.

Methodology

Study setup

The study is based on a systematic literature review (Punch, 2014) that is organized as a gradual process in which individual components are combined into a whole (Figure 1). In the first part, the separate fields of universal design, heritage buildings and sustainability have been briefly outlined. In the continuation, these areas are considered firstly cross-disciplinary and secondly multidisciplinary. This approach allows to assess the literature from various perspectives and also enables to evaluate the problems that are not encountered in separate-area studies and might be otherwise overlooked.

The literature covered in this review has been searched through various scientific bases, e.g. Science Direct, World Wide Science and Emerald. Also, other relevant Web sources were searched for project information, reports, legal documents, recommendations and standards. The search was especially concentrated on publications from 2000 to 2019 written in English, as the research questions focus on the latest developments and future challenges. To obtain relevant sources, the first step encompassed structured search for specific keywords and combinations of keywords in the search engines. The selection of keyword combinations was based on the main topics, e.g. heritage building, accessibility and sustainability, to get a glimpse of what the most general search within the topic can produce. The basic keywords used in the search and their relevant results are presented in Table I:

• “search word” describes what word combination was used to perform the search;

• “database” represents the database used for the search;

• “hits” reveals how many results the search produced;

• “title + kw” shows how many of the hits that were reviewed comprised titles and keywords relevant to this review;

• “abstract” represents how many of the abstracts fitted this review’s mandate; and

• “article” describes the amount of general article content that is relevant to this review.

In the initial search, the amount of relevant articles was generally quite low. When the search was narrowed to the last or the last number of years, it was difficult to find an appropriate number of articles with high relevance. While searching and selecting articles to look further into, the relevance criteria of age were however considered, and newer articles were more accessible.

After receiving a large number of results which had low relevance, more specific combination of keywords was used (e.g. historical building, listed building, revitalization, refurbishment, retrofit and adaptive reuse in combination with sustainable, environmental, life cycle, building performance and with universal design, accessibility and disabled persons). For this part, forward snowballing was also used (Wohlin, 2014). The already retrieved articles were scanned for relevant keywords or expressions, and, as a way to obtain relevant articles, some new keywords (e.g. deep renovation, inclusive design and impairment) were added to the existing keywords. Where possible the database search was set to search for articles according to relevance and publishing year. Many new keyword combinations resulted in a large number of hits; however, only the first few result pages gave relevant articles conforming to the search criteria. Furthermore, some databases produced very similar results, which reduced the need to use all databases. The narrowing and filtering of articles was executed on the basis of the articles’ title, keywords, abstract or title content relevance. The final selection was based on the research questions stated in the introduction. More than 350 sources were collected and checked for relevant contents. Finally, 120 sources were selected for further analyses.

On their basis, the latest state-of-art has been critically assessed and the developments along with research gaps and potential future research focuses, have been identified. Finally, the main trends and future perspectives associated with the heritage buildings retrofitting measures were identified along with the employed strategies that affect decision-making. Findings of the study are the basis for further research and development of enhanced strategies for retrofitting and adaptive reuse of heritage buildings in the view of universal design:

RQ1.

Which topics of sustainability and universal design are covered by literature in heritage projects?

Heritage and sustainability

Heritage buildings can be considered as a functional (Romeo et al., 2015) and a non-renewable resource (Roter Blagojević and Tufegdžić, 2016). As such they have to be appreciated as a valuable asset that has to be treated with utmost care. In their work, Roter Blagojević and Tufegdžić (2016) note that the introduction of sustainability principles has changed the approaches towards preservation and development of historic areas and buildings. Also, government policies are moving towards urban heritage conservation strategies that introduce sustainable development, combining the idea of heritage safeguarding and quality of life (Versaci, 2016). This is an approach that is not limited to the preservation of the artefacts but focuses on environment as a whole with all its tangible and intangible legacy. Indeed, preservation and refurbishment of heritage buildings is a multidisciplinary activity that includes cultural, physical, digital, environmental, human and social aspects (COM 477, 2014), making it the key factor of sustainable strategies based on adaptive reuse and life cycle models (Fuentes, 2015; Xie, 2015; Filippi, 2015).

Heritage building rehabilitation is a unique opportunity to reach higher levels of environmental performance, by reducing buildings’ environmental impacts (Munarim and Ghisi, 2016). In spite of the fact that reconstruction can be an environmental load in itself, compared to demolition and construction of new buildings, refurbishment offers both economic and environmental benefits. Building repurposing through selective deconstruction and building system reuse and, furthermore, recovering building waste after demolition through material reuse and recycling, involving reduction of energy and resource consumption and other environmental impacts can be achieved for end of life building stock (Assefa and Ambler, 2017; Bullen and Love, 2010).

A special case is industrial heritage which possess a strong development potential, yet, it can also carry huge environmental and other burdens (e.g. the buildings, as well as the sites may present a potential environmental hazard). Many examples of conversion of urban brownfields and industrial heritage sites into greenspaces exhibit both social benefits and environmental gains. According to Kristianova et al. (2016), the benefits of regeneration of the former industrial sites to green areas include playground and recreational areas, enhance the scenic beauty and neighbourhood appeal, improve the living conditions, raise property values and provide ecosystem services, habitats for wildlife, foster adaptation to climate change and many others. For sustainable regeneration it is of great importance to employ an inclusive management of industrial and other heritage sites (Ifko, 2016). Restoration and conservation works should also take into account the different technologies and materials used in the course of work which may influence, e.g. workers’ health, acoustic impact and waste produced in the building site (Franzoni et al., 2018).

It has to be noted though, that in the recent years, the majority of heritage building studies has been focussed on energy efficiency (Table II), forming a huge basin of information (Blecich et al., 2016; Galatioto et al., 2016; de Santoli, 2015; Harrestrup and Svendsen, 2015; Murgul and Pukhkal, 2015; Tiberi and Carbonara, 2016; Walker and Pavia, 2015; Zagorskas et al., 2014; Webb, 2017). The important impetuses for energy efficiency studies are increasingly demanding codes and regulations in the field of building energy performance, as well as emerging rules regarding energy management and sustainability (EPBD 31, 2010; EE-03-2014, 2014; Vieites et al., 2015; AICARR, 2014; ASHRAE, 2017; EN 16883, 2017). Furthermore, Akande et al. (2016) state that with energy performance becoming a crucial factor, the operational phase of heritage building projects is gaining importance. In many heritage building projects, however, the operational phase is still not considered, and a systematic way of analysing energy performance during the operation is often lacking. They suggest baseline project planning, periodic updating, monitoring and managing the energy use pattern to optimize energy performance. Further to this, Wang and Xia (2015) propose optimal maintenance planning for building energy efficiency retrofitting from optimization and control system perspectives. In other types of buildings, operational phase is less represented, which generates a gap, especially in the field of user health and general comfort. In the field of heritage building maintenance, assessment of the functional service life cycle using statistical tools, allowing prioritizing the maintenance and preventive conservation actions is described by Prieto et al. (2017) and an expert system for predicting the service life of buildings based on risk management standards is presented by Prieto Ibanez et al. (2016). Both can be applied on homogeneous types of buildings.

Many comprehensive studies also consider thermal comfort in various types of heritage buildings (Martinez-Molina et al., 2016; Yung and Chan, 2012; Fabbri, 2013). However, there are very few studies on the comfort of PWD in heritage buildings, largely neglecting the consideration of inclusiveness, universal design, etc. Generally, it seems that user comfort majorly depends on the specific project quality. For instance, Rani (2015) presents a study on an office building, which was included in an adaptive reuse strategy. He notes that the occupants’ comfort in terms of the indoor environmental conditions was overlooked, causing dissatisfaction and negative impact on the occupants because of poor quality of the indoor air. Contrary to this, Mundo-Hernandez et al. (2015) present a post-occupancy evaluation study conducted in an old factory building converted into an art gallery. They state that in spite of the fact that the refurbishment works destroyed several historic building elements, the reuse of old industrial spaces seems pertinent and users perceive the building as comfortable. Especially interesting are the cases where the indoor conditions encompass both the user comfort and the heritage protection (Košir et al., 2010). Although methodologies for certification of indoor microclimate quality already exist (Litti et al., 2017), they do not encompass the cultural heritage buildings. In the framework of quality of indoor environment, aspects such as ease of access and comfortable use of the premises, which is very important for PWD, still remain to be considered.

Heritage and universal design

The area of heritage and universal design comprises many contradicting issues of building conservation and social inclusiveness. For Dischinger et al. (2012), the spatial accessibility presents much more than mere possibility to reach a desired point. The environment should also enable the user to understand its function, organization and spatial distribution, as well as allow him/her to safely, comfortably and autonomously participate in the activities. For this reason, Roulstone and Prideaux (2009) note that objective of equal access to the built environment is paramount and that reasonable adjustments of every environment should be implemented. This inevitably also includes architectural heritage in its many forms. Some authors, however, do not agree with the above perception and believe that adaptive reuse of architectural heritage can detrimentally change the social, cultural and historic values of historic buildings, especially when there is a change of the original function of the building (Ahn, 2013). In this respect, buildings that have been built earlier are less accessible than the newer buildings (Jamaludin and Kadir, 2012). Often internal configurations of heritage buildings are idiosyncratic, with steep narrow stairways, many passageways and tiny windows (Laws, 1998). These conditions present contemporary heritage managers with a range of problems relating to conservation, presentation as well as visitor management. Many times the space limitations and protective restrictions also limit the number of possible solutions.

For example, Andrade and Martins (2015) present a practical experience of visually impaired persons in cultural heritage buildings. They note that there are many difficulties regarding the existence of environmental information to aid the perception of people with visual impairment, particularly in religious buildings. A cultural heritage building, its elements and shapes represent more than the space of the building itself. For a visually impaired person, the architecture is experienced as language and the physical elements in the architectural object provide communication tools through which other ideas beyond the strict formal setting can be transmitted. The artefact, in this case the tactile model, should be used as a resource to facilitate the perception and experimentation of space. The building tissue is an information-gathering resource that will assist visually impaired individuals in understanding the space around them, contributing to their independence in locomotion, more effectively if used in conjunction with other forms of recognition of space. In the construction of mental models, the ideal is to relate the tactile and visual aspects of surfaces to represent the aspects found in the environment, so that the user can create an association of reality (Dias et al., 2014). Designers indeed need to think creatively to design a barrier-free built environment without sacrificing the heritage value of both exterior and interior space (Jamaludin and Kadir, 2012; AWARD, 2009).

Finally, Seduikyte et al. (2018) point to the social developments and other potentials of heritage buildings management innovations including refunctioning of heritage buildings, with attention to users’ comfort and low-cost heritage actualization initiatives (Table II). Adapting existing heritage buildings to new uses, especially to assisted living models has many benefits. Such approach proves to be substantially more cost efficient than the institutional care and can provide better comfort and the necessary social mix by a trans-generation communication in social housing (Kovacic et al., 2015).

Sustainability and universal design

Some authors consider that both universal design and green building design aim to achieve sustainability in the built environment (Yiing et al., 2013). We agree with this notion and furthermore consider them as complementary areas. Although sustainability and universal design share many common points such as social equality, inclusiveness and respecting of cultural diversity, the literature review shows that combined research on these two topics is represented in very small numbers. Majority of studies encompassing sustainability and accessibility are dealing with urban planning, transport routes and public transport features. Example of such research has been recently presented by Gil Solá et al. (2018), who carried out a study on sustainable accessibility in urban planning. They find that urban planning for sustainability is gradually shifting from car based to proximity ideals. However, when concretized in regular planning thinking and practice, the latter ideal becomes contested and complex. Although there is overall agreement, urban planners’ interpretations of sustainable accessibility (including planning in accordance with citizens’ rights to access basic services) and other related issues reveals several tensions when discussing how the related policies should be implemented. Disagreements relate in many ways to social considerations and to the socio-spatial distribution of resources.

One of the few studies that directly address the topics of sustainability and accessibility in the framework of housing renewal in Spain is the work by Ibarloza et al. (2018). They acknowledge the EU support for energy efficiency and universal accessibility is clear (COM 636, 2010; CPR 305, 2011). However, similar to other member states, in Spain, majority of housing was built prior to 1981, when the regulations did not cover either sustainability aspects, such as energy efficiency, or universal accessibility. The above authors claim, that new regulations bring a qualitative change into housing which may increase social cohesion. However these changes are also very complex and costly and this is slowing down the rate of refurbishments. These problems can be to some extent generalized, as the social and economic characteristics of ageing urban population (SWD, 2017) are similar in majority of countries. Evidently, there is a need for wider public support and more coherent refurbishment policies (Ibarloza et al., 2018).

Further to this, Yiing et al. (2013) analyse how these two sustainable development instruments are either being corroborated, compromised or complemented through the practice of providing accessibility to PWD in green buildings. They find that many times the buildings perceived as “green” are not as accessible as supposed, with accessibility features designed just for a certain group of PWD and employing inappropriate management measures such as blocked evacuation routes. Such issues can be avoided by introducing the principle of social sustainability. Kadir and Jamaludin (2013) maintain that social sustainability is a process for creating sustainable and prosperous places that promote well-being by simply understanding the peoples’ needs in the environment they occupy. They claim that in addition to the social development within a community, life cycle and growth of the individuals within their private living spaces are also significant as the underlying elements of social sustainability. As such, social sustainability can be defined as the collective process of life growth and interaction among humans within their surrounding environment, which evolves from the private domain to the public living environment (Kadir and Jamaludin, 2013). In spite of the fact that these two areas (sustainability and universal design) have a significant social and environmental potential, this issue has not attracted a lot of scientific attention:

RQ2.

Which challenges are foreseen related to universal design?

Interpretation of universal design

One of the problems repeatedly mentioned by researchers in the reviewed literature is the (mis) interpretation of the terms “universal design” and “accessibility”. Differences in interpretations can be detected in various groups of stakeholders and both in general built environment and in heritage buildings. Although the concept of universal design principles have been established for nearly two decades and they act as a foundation for measuring and evaluating accessible designs (Mustaquim, 2015), the designers, facility managers and users perceive the two concepts in a very different way. Universal design philosophy is a transfer towards inclusive solutions for people with diverse abilities (e.g. “design for all”). Nevertheless, according to Mustaquim (2015), in practice it often becomes a mere conception, and existing theoretical guidelines as design principles often fail to result in actual universal design. One of the possible reasons for such situation is the unawareness of the involved stakeholders about the basic principles of the universal design and accessibility requirements. To explain the differences, the sustainable facility management discipline, which has been increasingly researched since 2005 (Jensen and Balslev Nielsen, 2008; Balslev Nielsen et al., 2009; Junghas, 2011), can be employed. It integrates multiple disciplines to have an influence on the efficiency and productivity of economies of societies, communities and organizations, as well as the manner in which individuals interact with the built environment, and it affects the health, well-being and quality of life of much of the world’s societies and population through the services it manages and delivers (ISO 41001, 2018).

For example, the study on level of awareness and perception of building managers regarding current and future plan of building’s accessibility and their knowledge on universal design theory (Kadir et al., 2012) shows that some misinterpreted universal design as disability design that merely caters the need of PWD’s accessibility in architecture and the surrounding environment. They also perceived their building as accessible to building’s visitors; however, their understanding of universal design in terms of the application in areas other than built environment could be improved. Further studies on how facility managers recognize and practice universal design in the workplaces (Ormerod and Newton, 2005; Saito, 2006; Jaeger et al., 2015; Finch, 2017; Boge et al., 2018) emphasize the importance of managers for ensuring accessibility for all workers. The study by Saito (2006) indicates that many facility managers recognize the advantages of universal design; however, most studied organizations currently provide accessible workplaces merely within the scope of legal requirements. Only few organizations achieved consistency between corporate mission and strategies, knowledge of facility managers and the degree of workplace accessibility practices. Sometimes even occurred that organizational policymakers used the universal design terminology for commercial success and claimed its positive impact on accessibility causes, leaving the true outcome to be achieved. Some authors report that in a certain design phase policymakers introduce some new properties and later claim them to be universally designed, which in practice is not the case (Mustaquim, 2015).

It can be noted that regardless of numerous guidelines and design principles addressing many needs of various groups of population, it is important that they are well understood by different stakeholders so that incorrect policymaking does not occur (Mustaquim, 2015). Some of the current facility management practices appear to be failing many disabled users (Finch, 2017). Facility management role is important to take act on strategic, tactical and operational level for daily services and from maintenance and investment purposes. Finch (2017) states that facility management needs to recognize that the part “management” presents a minimum standard; to run an inclusive business or an inclusive service they have to go beyond that. The findings also suggest that an understanding of the issues by top management is the key for promoting universal design practice (Saito, 2006).

Parallel to this, the reviewed studies also identify lack of awareness about the importance of barrier-free environment in the wider community (Kadir et al., 2012). Sometimes, even the direct users (e.g. elderly PWD) are not concerned about the universal design practice, and neither are they aware of what to expect in a setup in which they spend their daily life. The individuals subconsciously regard other factors to be important and wish them to be included in their life (e.g. social factor) (Mustaquim, 2015). This finding corresponds with the work by Kadir and Jamaludin (2013), which defines social sustainability as a combination of the physical realm and the social world. This implies that the design of the universal physical environment is the basis for sustainable development. PWD wish to be a part of the evolving society. As Finch (2017) remarks, this is a sphere of innovative business practices and stimulating work settings. The facility management should reflect the disabled-smart thinking, mentality that captures the richness of a diverse organization. Once the awareness rises, it becomes clear, that the boundaries and limitations do not lie inside a person but rather in the environments, products or services (Ergenoglu, 2015).

Education and training

One of the ways to augment public awareness on universal design in correlation to heritage and sustainability is through education. The discipline that strongly influences the creation of built environment is undoubtedly architecture. In the UNESCO/UIA (2011) Charter for Architectural Education, it is defined that “it is in the public interest to ensure that architects are able to understand regional characteristics and to give practical expression to the needs, expectations and improvement to the quality of life of individuals, social groups, communities and human settlements”. It is further stated that “architecture, the quality of buildings and the way they relate to their surroundings, respect for the natural and built environment as well as the collective and individual cultural heritage are matters of public concern”. Among other, “architectural heritage education is essential to understanding sustainability, the social context and sense of place in building design”. In the knowledge section, the social context is further developed and “understanding of the social context in which built environments are procured, of ergonomic and space requirements and issues of equity and access” is also included. In EU, the institutions and the Member States are called upon to work to build a barrier-free environment for all. It will encourage the incorporation of accessibility and “design for all” in educational curricula and training for relevant professions (COM 636, 2010).

In majority of countries, architectural studies comprise all of the above-mentioned contents, including courses on universal design and accessibility. However, many times they are insufficient or inadequate (Türk, 2014), which makes it difficult for this notion to be widely known and adopted. The objective, therefore, is to invest into human resources and improve the understanding of universal design principles, along with other important fields. Ergenoglu (2015) considers that the universal design education, by nature, comprises a multi-professional and interdisciplinary approach. However, when the courses on universal design and accessibility for architects contain mostly standards, rules, regulations and design problems, students tend to focus on technical matters rather than users. Furthermore, when designers tend to ignore the human aspects, environments may become accessible; however, they do not reach the level of inclusivity. Further, Bringolf (2008) points out that education and “re-branding” of universal design may also help to eliminate the misinterpretation of universal design as a disability product. In this context, Ergenoglu’s (2015) suggestion that the term “disability” should be redefined and that the term “diversity” might be used instead of “disability” merits attention. When the concept of disability is considered in correlation with a person and environment rather than a disabled individual, the attention given to the impact of the environment upon individuals’ potential can become more significant (Ergenoglu, 2015).

As can be seen, higher education institutions are the most engaged for rising awareness of professionals and other society members. Afacan (2011) reports that among the students of architecture, there is a notion that high complexity of various requirements in conjunction with deadline limitations prevents them to correlate the information gained in separate courses. More time and practical training dedicated to universal design would be necessary. Also vocational education in this field (AWARD, 2009) and lifelong learning are important to educate skilled workforce with knowledge and understanding of universal design principles. Additionally, society as a whole needs to be educated about the importance of barrier-free environment and PWD rights and capabilities (Kadir et al., 2012). The comprehensive consideration of universal design within the curriculum contents is essential. Moreover, it has to be stressed that most of all the principles of universal design have to be incorporated into design process and have to become a fundamental aspect of design education as such. In this way, Ergenoglu (2015) says, effective universal design education has to contribute to the creation of the future architects’ values and help remove the environmental barriers, providing environments to be designed inclusively from the beginning of the design process, with a holistic and sustainable perception of the designer. Because the field is continuously developing, the students and practicing architects should to be able to learn and observe on their own. Learning from practical experience should be a vital part of universal design courses (Ergenoglu, 2015).

Complexity of decision-making

The interconnectedness of the three considered areas forms a very demanding engineering task, although in practice, integrated approaches involving overlapping of several fields are becoming increasingly implemented (Pisello et al., 2016). Versaci (2016) brings to attention extensive knowledge, participatory approaches, cultural and natural vulnerabilities management, combination between heritage and planning strategies, development of civic engagement and financial tools that have to be employed in the process of design, construction and management. In this respect, Kovacic et al. (2015) propose a complex life cycle-based renovation strategies, including structural and thermal refurbishment, social aspects of an ageing society and preservation of cultural heritage. Their study includes life cycle costs and yields, ecologic (CO₂ emissions) and socio-cultural impacts (monument protection, accessibility and assisted living). Many authors agree that life cycle model, which would take into account embodied energy in existing buildings, could be a key factor to develop sustainable strategies based on adaptive reuse and a consequent prolongation of the building lifespan (Fuentes, 2015; Xie, 2015).

Many studies suggest that the complexity caused by presence of various objectives to be pursued (Ferretti et al., 2014), the public/private nature of the goods under investigation, the existence of several values (historical, architectural, social, cultural, economic, etc.), the involvement of different stakeholders (public, government representatives, architects, architectural historians, developers, various users and owners) can hinder the speed and quality of decision-making. It has been generally agreed that multi-criteria decision analysis can offer a formal methodology to deal with such decision problems, taking into account the available technical information and stakeholders’ values (Stendebakken et al., 2015; Ferretti et al., 2014). Experience from other related fields can present a large advantage and can enable the transfer of knowledge also to these areas. For a retrofitting project, Fregonara et al. (2017), for instance, propose a multidisciplinary decision-making approach, comprising the contribution of real estate market and economic evaluation of project, architectural technology and building physics, application of the life cycle costing methodology and energy analyses. Kamari et al. (2017) present a comprehensive sustainability framework to audit, develop and assess building renovation performance and support decision-making during the project’s life cycle, addressing sustainability of the entire renovation effort including new categories, criteria and indicators. Further studies in the field of industrial heritage suggest a similar paradigm. Merciu et al. (2014) propose a structural and typological analysis of the forms of industrial heritage; Penića et al. (2015) develop a revitalization method with the purpose to preserve and restore historical landmarks, which assign a new function; Becchio et al. (2016) present a cost-optimal methodology, conceived for national authorities as a decision-making tool for supporting a private investor in choosing the most viable energy scenario; Claver et al. (2015) propose a global methodology for the study of the built heritage; and Virtudes and Almeida (2016) propose an ICT method for evaluation of conservation.

A holistic manner of approach evokes the need for a cross-disciplinary working team (Stendebakken et al., 2015), which can inhibit work because of various approaches and communication gaps between the involved stakeholders (Ferretti et al., 2014). To solve this problem some researchers suggest a holistic approach to adaptive reuse strategies for heritage buildings (Misirlisoy and Gunce (2016). The finding and comparing of optimal retrofits for historic buildings is achieved by multi-objective optimization that comprises multi-perspective and quantitative assessment. The proposed procedure is an analytical hierarchic process for quantification of refurbishment compatibility (Roberti et al., 2017) and who suggest a holistic approach to adaptive reuse strategies for heritage buildings (Misirlisoy and Gunce (2016). Claver et al. (2015), however, bring attention to another important fact that additionally increases the complexity of the field. Specifically, there exist different built heritage typologies, and each one has a particular nature. The same aspects are not equally important in all the cases. The need to simultaneously consider different criteria with different levels of importance makes it reasonable to think in multi-criteria methods. Kamari et al. (2017), e.g. suggest the use of a multi-dimensional approach and application of soft systems methodologies with value focussed thinking.

Discussion and conclusion

The review shows that at the declarative level as well as in the research field, the separate areas of the built heritage, sustainability and accessibility are well covered. For example, these fields are underpinned with several strategic documents (WHO, 2011; CRPD, 2006; UIA, 2011; ICOMOS, 2011; UN, 2019), which are also introduced into national strategies. Likewise, the regulatory system on these topics is well established and frequently updated (TEK 17, 2017; ZVKD-1, 2008). Also, many studies deal with important questions in the field of sustainability, heritage protection and accessibility (Table III).

On the other hand, the combined field of sustainability and heritage buildings is not well represented and is currently concentrating mainly on energy efficiency. The foremost reasons behind such situation are the current policies strongly focussing on the building energy performance (EPBD 31, 2010; EE-03-2014, 2014). Such orientation will presumably maintain the research interest on this specific issue also in the future. Yet, also more holistic approaches to the area which include several pillars of sustainability are emerging. One of them is the EU Level(s) system, which introduces a general language of sustainability to the buildings (Dodd et al., 2017) and makes the decision making more focussed and proficient. With well-defined and measurable sustainability indicators, historical areas and buildings can be restored and adapted to contemporary requirements, using sustainable philosophy of built environment and providing them with a suitable function and continuous maintenance (Roter Blagojević and Tufegdžić, 2016).

The dual field of accessibility and heritage buildings is not well studied. Although the literature provides numerous recommendations for application of universal design (Steinfeld and Maisel, 2012; MESP, 2017), they are often too general for the specific issues that can be encountered in heritage buildings. Sometimes the building geometry itself, as well as specific heritage protection requirements prevent the designers to implement certain solutions. Universal design should form an important part of building maintenance and management with social dimensions included as an inseparable segment of the built environment. The importance of cross-disciplinary approach and complex decision-making is accentuated by the fact that presently the decisions are many times carried out in the framework of the respective influence of the involved stakeholders and the requirements that need to be addressed. This also shows the need for more specific recommendations that would address the questions of accessibility in heritage and historical buildings. The problem-solving methods should be based on holistic approach, which would form the base for implementation of universal design principles into refurbishing of heritage buildings. One of the issues that frequently emerges in the studies are various interpretations of the universal design and accessibility in buildings. This shows the need for the society to be educated about not only the importance of barrier-free environment and PWD abilities but also the principles of universal design. It also demonstrates that universal design is not yet considered a prerequisite in the built environment instead of an additional benefit. Especially user focus is not well studied, forming a gap in the field of comfort and universal design aspects in heritage buildings. A small number of studies, though, consider refunctioning of the built heritage, with attention to users’ comfort and low-cost heritage actualization initiatives, such as assisted living models and social housing (Ibarloza et al., 2018; Kovacic et al., 2015). This presents a welcome source of information on the complex and cross-disciplinary field of universal design approaches in heritage refurbishment.

Finally, in the reviewed literature, few interrelations between the three considered topics can be found. It seems that harmonizing the requirements of built heritage, sustainable development and universal design is a challenging task that comprises various aspects. Dealing with different views and stakeholder interests currently produces somewhat heterogeneous approaches to the considered topics with some areas being mainly overlooked. This is especially true for heritage in regard to accessibility questions and universal design (Table II). Such situation shows the need for cross-disciplinary decision-making methods that would assist the various stakeholders (e.g. practicing architects and public authorities) in holistic knowledge base approach in search of the best solutions. It also demonstrates the need for usable procedures that stakeholders could use in their everyday practice. Accordingly, educational approaches and practical training focussed on universal design, such as specialist and vocational training as well as lifelong learning, need to be further developed. The studied research indicates opportunities for further investigation, especially the need for an adequate, in-depth assessment of sustainability issues in heritage buddings refurbishment. It also shows the need for further development of manageable processes for introduction of universal design principles into the heritage buildings refurbishment, maintenance and management. The main identified points are the importance of user-oriented design and inclusion process that need to be further developed.

Figures

Figure 1.

Flowchart of the study and basic outline of the considered topics

Table I.

Number of hits and relevant studies content on combined topics of accessibility, sustainability and heritage buildings

Search words	Database	Hits	Title + keywords	Abstract	Article
Heritage building sustainability	Science Direct	12,215	34	12	3
	World Wide Science	1,420	53	12	3
	Emerald	2,022	10	8	0
Heritage building accessibility	Science Direct	5,100	4	1	0
	World Wide Science	2020	2	0	0
	Emerald	1326	1	0	0
Sustainability accessibility	Science Direct	37,746	5	5	1
	World Wide Science	3910	1	0	0
	Emerald	2934	1	0	0
Heritage building sustainability accessibility	Science Direct	1,330	4	2	0
	World Wide Science	1909	2	0	0
	Emerald	521	0	0	0

Table II.

Studies on combined topics of universal design, sustainability and heritage buildings

Topic and Subtopic	Source	Document title	Keywords
Accessibility and sustainability
Universal design	Kadir and Jamaludin (2013)	Universal Design as a Significant Component for Sustainable Life and Social Development	Universal Design, social sustainability, social development
Sustainability and accessibility	Ibarloza et al. (2018)	The needs and effects of housing renewal policies in Spain: Implications for sustainability and accessibility	Housing renewal, Ageing population, Sustainability
Accessibility	Gil Solá et al. (2018)	Understanding sustainable accessibility in urban planning: themes of consensus , themes of tension	Sustainable accessibility
Refurbishment	Kovacic et al. (2015)	Strategies of Building Stock Renovation for Ageing Society	Life cycle costs, social housing, assisted living, thermal refurbishment, sustainability
Accessibility and heritage
Management	Laws (1998)	Conceptualizing visitor satisfaction management in heritage settings: an exploratory blueprinting analysis of Leeds Castle	Heritage Service quality
Heritage and sustainability
Energy use	Akande et al. (2016)	Performance Evaluation of Operational Energy Use in Refurbishment, Reuse, and Conservation of Heritage Buildings for Optimum Sustainability	Heritage buildings Listed churches Operational energy Refurbishment Sustainability
LCA	Assefa and Ambler (2017)	To Demolish or not to Demolish: Life Cycle Consideration of Repurposing Buildings	Repurposing Life cycle assessment Sustainability
Retrofitting	Filippi (2015)	Remarks on the Green Retrofitting of Historic Buildings in Italy	Cultural heritage buildings Green retrofitting project
Retrofitting	Fregonara et al. (2017)	Retrofit Scenarios and Economic Sustainability. A Case-study in the Italian Context	Energy Retrofit Economic Sustainability Life Cycle Costing
Management	Seduikyte et al. (2018)	Knowledge Transfer in Sustainable Management of Heritage Buildings. Case of Lithuania and Cyprus	Heritage buildings Knowledge transfer Built heritage management
Decision-making	Kamari et al. (2017)	Sustainability Focused Decision-Making in Building Renovation	Sustainability Building renovation Decision support
Adaptive reuse	Tam et al. (2016)	Adaptive reuse in Sustainable Development: An Empirical Study of a Lui Seng Chun Building in Hong Kong	Adaptive reuse Historic building Sustainable

Table III.

Legislation and recommendations on building heritage, sustainability and accessibility

Topic	Source	Document title	Level
Accessibility
International	WHO (2011)	World report on disability	General
	CRPD (2006)	UN Convention on the Rights of Persons with Disabilities	General
	SWD (2017)	COMMISSION STAFF WORKING DOCUMENT Progress Report on the implementation of the European Disability Strategy	General
	EIDD (2004)	Good design enables, bad design disables, The EIDD Stockholm Declaration, EU	Accessibility
	COM 636 (2010)	European Disability Strategy 2010-2020	General
	ISO 41001 (2018)	Facility management – Management systems – Requirements with guidance for use	General
	CPR 305 (2011)	Construction Products Regulation No. 305/2011	General
National (example)	Ministry of labour et al. (2014)	Action plan for impaired persons 2014-2021	General
	TEK 17 (2017)	Regulations on technical requirements for construction works, Norway	Specific requirements
Built heritage
International	UNESCO (2011)	Strategic action plan for the implementation of the world heritage convention 2012 - 2022	General
	UNESCO/UIA (2011)	Charter For Architectural Education, Revised Edition	General
	ICOMOS (2011)	The Paris declaration on heritage as a driver of development	General
	Europa Nostra (2009)	Why cultural heritage matters for Europe	General
	COM 477 (2014)	Towards an integrated approach to cultural heritage for Europe	General
National (example)	ZVKD-1 (2008)	Cultural Heritage Protection Act, Republic of Slovenia	Specific requirements
Sustainability
International	UN (2019)	The Sustainable Development Goals Report 2019	General
	COM 614 (2015)	Closing the Loop – An EU Action Plan for the Circular Economy	General
	COM 445 (2014)	Resource Efficiency Opportunities in the Building Sector	General
	EE-03-2014 (2014)	Energy strategies and solutions for deep renovation of historic buildings	General
	ASHRAE (2017)	Guideline 34 P, Energy Guideline for Historical Buildings	Specific requirements
	EN 16883 (2017)	Conservation of cultural heritage, Guidelines for improving the energy performance of historic buildings	Specific requirements
	EPBD 31 (2010)	Directive 2010/31/EU of the European Parliament and of the Council on the energy performance of buildings (recast))	General, specific
	CPR 305 (2011)	Construction Products Regulation No. 305/2011	General
National (example)	AICARR (2014)	Energy Efficiency in Historic Buildings	Specific requirements
	Ministry of infrastructure, Republic of Slovenia (2016)	Guidelines for energy retrofitting of built heritage	Specific requirements