Criteria for Assessing Suitability: Choosing New Functions for Historic Buildings
Yang Qiyuan
A0283707X
A dissertation submitted for the degree of master of art in architectural conservation Department of architecture
National university of Singapore
May\2024
Acknowledgement
First of all, I would like to express my heartfelt thanks to my supervisor Dr. Wong Yunn Chii. His guidance during the process of thesis creation, with giving me detailed and insightful feedback at every stage promoted the completion of this dissertation. What I learned is not only the knowledge about this topic, but also a systematic approach to dissertation writing and the right method of literature reading. Professor's vast knowledge and deep insight into the history of architecture broadened my perspective. At the same time, I am also grateful to Professor Johannes WIDODO, HO Puay Peng and Nikhil JOSHI for teaching me new knowledge, and more importantly, bringing some different learning methods during the study and your extensive knowledge and unique insights into the profession have stimulated my interest about architectural conservation and to keep learning in this field.
Also a heartfelt thank should be given to my family members for supporting me in studies, giving me encouragement, and bringing me motivation to keep going. Finally, I would like to express gratitude to myself, to be able to keep moving forward and hopefully meet a better version of myself in the future.
The length of this dissertation is 8858 words, inclusive of the main body of texts, abstract, captions, and table of contents, but excluding bibliography, list of figures and tables, acknowledgement, footnotes and endnotes, and appendices.
List of table or figure:
Table 1 Scopes of application of the formula and meanings of the parameters
Fig.1. Framework of decision-making process
Abstract: In order to ensure sustainable heritage conservation, this research paper explores the adaptive reuse of historic structures, examining the intricate process of making decisions that takes society, economy, and environment –these three aspects into account. In light of the growing difficulty of preserving cultural authenticity while satisfying contemporary requirements, the research introduces the ARP (Adaptive Reuse Potential) model as a systematic technique for ranking historic structures for adaptive reuse. The research highlights crucial success criteria and impediments through a methodical assessment of the literature and content analysis, offering a framework that helps stakeholders make well-informed decisions about new uses for historic buildings. The research paper promotes adaptive reuse's role in urban regeneration and sustainability by highlighting its advantages on the social, economic, and environmental fronts. The approach encourages a dynamic use of space that respects historical relevance while reflecting modern demands, in addition to supporting the preservation of architectural legacy.
Key words: adaptive reuse, historic buildings, heritage conservation, decisionmaking model, ARP model, environmental impact of reuse, economic benefits of reuse, social implications of reuse
1. Introduction and research aim
Historic buildings should be protected and preserved because they serve as an invaluable reminder of customs, values, and tradition that enrich their communities. Throughout history, several buildings have served various purposes during various eras. However, as public awareness of the need to preserve the built environment has increased, decisions of new functions during the process of adaptive reuse need to be made with greater professionalism. In order to preserve the cultural significance of the historical buildings, it is imperative to choose the most suitable functions within the given setting. Modifying a building's function results in the introduction of additional legal requirements. A heritage building's new use can be tough to decide because numerous aspects need to be considered The choosing of a new use for historic buildings at random without proper examination is a primary issue with adaptive reuse initiatives.
The objectives of this research are to present a comprehensive analysis of the factors influencing adaptive reuse decision-making and to offer a model for adaptive reuse strategies for heritage buildings. Consequently, two goals will be accomplished. The main objective is to identify the elements that impact decision-making and to provide an extensive analysis of the variables affecting historic buildings’ adaptive reuse. Aiming to determine the variables influencing decision-making of adaptive reuse, pertinent research studies on the subject have been chosen. The establishment of a model to ascertain, in light of the
factors stated, the second objective is to determine the best role for adaptive reuse of heritage structures. This section of the study suggests a paradigm for developing strategies for adaptive reuse of historic buildings that are vacant, misused, or improperly operated. By taking all relevant elements into account, decision-makers will benefit from the model's assistance in developing the best possible strategy for the future use of historic buildings and ensure that adaptive reuse initiatives are successful. The interplay and complexity of all the problems surrounding adaptive reuse are growing. Investigating the connections between financial, environmental, and social factors is the goal of this model. This paper also discusses the ARP model because it may be applied more broadly than other variables or approaches to determine whether a historical building can be used again, and it is not restricted to evaluating a specific building and might be highly referenceable in other adaptive reuse projects. With the use of this model, historical buildings with a high potential for adaptive reuse can be identified and prioritized, which can help property stakeholders shift their typical decision-making procedures in the direction of more environmentally friendly methods, plans, and results. This in turn makes it possible to choose historic buildings with greater potential for reuse at the right moment and to put those structures into practice with the right management strategies.
Even adaptive reuse projects frequently generate positive results, some projects have not yielded the expected consequences. The elusive nature of
success and the ambiguous meanings of "adaptive reuse" contribute to the lack of understanding of why some projects are successful while others are not, or even what exactly qualifies as "success". The issue, " What criteria can be applied to evaluate an adaptive reuse project's success?" must be taken into consideration. While some studies have identified success factors, there is a lack of a comprehensive categorization or systematic classification. Adaptive reuse solutions are implemented by designers, architects, and real estate developers. This paper attempts to give a detailed explanation of the elements that affect the effectiveness of adaptive reuse as a historical building regeneration strategy Additionally, this paper seeks to answer the question using a more systematic, comprehensive and scientific approach.
2. Methodology
This study depends on the notion of historic adaptive reuse projects' success, however, it is difficult to define because there are many competing theories. The elusive nature of the term "success", the multiplicity of readings from different perspectives, the breadth of the fields of studies, and the combination of measurable and non-measurable parameters make it difficult to accurately classify the concepts, elements, and standards that influence any project involving adaptive reuse in its success. Consequently, the effectiveness of an adaptive reuse approach cannot be determined by a single, universal solution. In order to extract and analyze the success criteria, this research uses a
methodical literature review process that enables an elaborate and wellstructured classification.
First, a literature survey was used to gather the data, then content analysis was used to determine the contributing components. In light of review of literatures, there are some considerations that come into play while choosing an appropriate use for historic buildings that can be adaptively reused. The model was created with the defined factors in mind.
Methodologies of comparison and analysis are used in the chapter two to compare different factors, models and approaches in current studies that can be used to estimate adaptive reuse potential, with analysing scopes of application, and limitations to select a model that could be used in a wider context and facilitate referencing for other reuse projects.
3. Significance of adaptive reuse and appropriate selection of new functions
Future generations can better comprehend heritage buildings by preserving them and adapting new uses based on their sizes, potentials, and locations.
Rehabilitating historic structures benefits local communities socially and environmentally while also assisting in the preservation of the nation's cultural heritages. Preserving architectural identity, style, and the buildings' alleged "solid build qualities" through adaptive reuse are highly prized. Historic building demolition is now regarded as an ecological waste, along with the loss of socioeconomic values, cultural heritage, and local identity as society grows more
conscious of ecological issues. Adaptive reuse can be used to make historically significant buildings usable and accessible, which also guarantees that new areas are occupied in a sustainable way. In certain cases, there's a chance that adaptive reuse is the only way to uncover, interpret, or protect a building's shape and structure while improving how well it is used in its new role. When historical buildings are repurposed adaptively, the original builders' labor, expertise, and commitment are preserved in addition to the building itself. Essentially a type of heritage conservation, historical building repurpose preserves the architectural, social, cultural, and historical qualities as well Improved efficiency of materials and resources, expense savings, and preservation are some of the results of adaptive reuse.
3.1 Environmental benefits
If reducing energy consumption and environmental sustainability are also goals, then adaptive re-use approaches are better than demolition. When it comes to dealing with buildings, demolition is not as feasible or efficient as adaptive reuse. Because it lessens the chance of dust and material falling, polluted ground, and disruption from hazardous chemicals, it is thought to be a safer approach. Specifically, since the current structures has a work cage which decreases pause time due to weather, site operations is also more easy to carry on. It is important to recognize that demolition is an environmentally harmful activity. Repurposing buildings reduces waste, material consumption, and
energy consumption compared to demolishing and reconstructing. Reusing structural components throughout the adaptive reuse process, recycling materials, and reducing landfill trash can all have a positive impact on the environment. These benefit the owner financially, but they also have far more extensive environmental effects. Occasionally, high-quality materials that have a far longer usable life than their more contemporary counterparts such as solid stone walls and marble floors were used in the construction of older structures. Furthermore, many components of historic building facades lower energy use and improve building efficiency, with regard to potential external noise, pollution, and thermal disturbances. Specifically, the external envelope of many older buildings uses enormous construction This can deliver long-term operational benefits and reduce energy usage for heating and cooling. When pollution and noise from the outside are not a problem, natural ventilation, natural lighting, and opening windows are all ideal features. Additionally, lowrise buildings do away with the requirement for expensive vertical transit networks. The adverse effects of pollution resulting from construction activities can lead to the decline of biodiversity, lower the quality of water and air, as well as modify ecosystems. Because they are already in place, old buildings can eliminate the requirement for new infrastructural systems like gas, drainage, sewage, and water, saving responsible authorities money and time. Reconstruction and demolition are considered unsustainable since they are thought to be wasteful. Adopting re-use means that recycling and repurposing is
prior to demolition as a way of construction. Reducing land fill, producing less trash, reducing material transportation, reducing urban sprawl, repurposing existing infrastructure, and consuming less raw materials are some advantages of this construction method. When materials are reused or left on site, embodied energy is also decreased. The building's capacity to fulfill energy consumption, operating costs, repair and maintenance benchmarks all contribute to its environmental benefits. Preserving the original building's "embodied energy" was found to be a benefit to the environment from repurposing constructed assets, its reduction can make a project environmentally viable. The embodied energy of new structures is significantly higher than that of adaptively reused buildings. Reusing construction materials can result in significant embodied energy savings above what would otherwise be thrown away.
Examining the benefits that adaptive reuse might offer while considering environmental issues must include sustainable development. The sustainability of existing buildings can be greatly enhanced by adaptation, which can help to promote the development of a sustainable built environment and be seen as a less wasteful and energy-intensive substitute to building replacement and demolition. Reusing historical structures is a sustainable approach that is supported by both the useful results of flexible repurposing and the theoretical principles of conservation
Over the past ten years, one of the most keenly debated topics in urban planning and architecture has been sustainability. Reusing and adapting buildings has started to become more and more common in the built environment. One feature of sustainable ecosystems is adaptively repurposing current building stocks. Sustainable cities and architectures will also benefit from sustainable heritage adaptations. By making use of the current stocks of buildings, historical buildings’ adaptive reuse contributes to the encouragement of environmentally sustainable. Adaptive reuse extends a building's life and reduces pollution, material, transportation, and energy consumption. It also plays a major role in sustainability. On the other side, by maintaining and revitalizing the heritage buildings, it guarantees the conservation of cultural identity.
3.2 Economic benefits
From an economic perspective, it is sometimes more cost-effective to modify an existing structure to meet new requirements rather than to construct a new one. This implies that the expenditures associated with reusing a building are sometimes less than those associated with demolishing it. Rehabilitating typically takes less time than reconstructing or rebuilding, which lowers costs. Because the contract lengths are usually shorter, this also results in lower financing periods and lower borrowing costs. A shorter construction period also has the benefit of lessening the impact on tenants or asset owners since it
allows for a return to full functionality by minimizing disruption to everyday activities.
Reusing materials is financial saving even with its time benefits. Reusing structural parts results in significant savings and lower costs when altering a building's role because many of the interior elements and structural components are already present, provided there are no costly issues to solve.
Nonetheless, there has been widespread debate about the proportionate expenses, associated advantages, as well as limitations of reuse as opposed to new building and demolition. Since there is no need for demolition and structural elements can be reused, adaptive reuse projects are seen to be more cost-effective, however they can also be more expensive.
When it comes to creating a revived area, compared to demolishing, and starting over with a new building, adaptive reuse is a more productive and successful. A place gains intrinsic heritage value when historic buildings are conserved. Preserving an area's style and characters adds value to its heritage value and helps create visually appealing streetscapes. In general, it is better to reuse a historical building rather than replace it, since a new building 's quality and location may not always be superior to that of the historical one. These elements raise the building's worth along with increasing the value of nearby assets. An organization may find historic buildings more appealing because they confer status through the use of finely constructed materials.
In summary, there is a rising perception that renovating existing structures rather than demolishing and rebuilding is more affordable.
3.3 Social benefits
One important way that adaptive reuse affects society is through the social value that built assets provide.
Older structures might occasionally offer social advantages like inherent heritage significance It is known that adaptive reuse is a tactic for extending a building's environmental criterion so that it can fulfill a new use while maintaining its historic significance. Historical buildings are typically found in urban areas and next to transportation hubs, making them easily accessible to the general population. They foster a feeling of community and are frequently valued by tenants as cozy workspaces.
Rehabilitating aging or decaying buildings gives well-known landmarks fresh life and vitality, which enhances the city's reputation. Preserving styles, characters, and the sturdy construction characteristics of structures is highly valued.
Historic sites that are sustainable ought to comprise “reflecting local life, maintaining local identity, diversity and vitality, minimise the depletion of nonrenewal heritage assets, develop collective responsibility for heritage assets, provide a robust policy framework for integrating conservation, objectives with the aims of sustainable development more generally” (Pickard, 1996). Urban
regeneration may be aided by the preservation of historical areas inside cities and their subsequent reusing for a range of purposes. Furthermore, it would be advantageous for future generations to preserve specific locations and urban areas. With adaptive reuse, an asset can be put into use in a way that can meet changing stakeholder needs while also preserving its physical attributes. Reusing historical buildings can open new residential and business prospects for the neighborhood.
Rehabilitating outdated or decaying buildings also contributes to the vitality of local communities, combats crime, and upholds anti-social norms. A city's community suffers when there are a lot of abandoned or vacant buildings because it creates a conducive climate for crime and other antisocial conduct.
Investing in an adaptive reuse program can help rejuvenate and reenergize these places that have been neglected, which will raise living conditions in the neighborhood.
The application of an adaptive reuse method is able to result in the creation of additional jobs. Compared to demolishing and rebuilding, adaptive reuse offers more opportunities.
In conclusion, the only option to maintain and protect heritage value of historic buildings when it is no longer used for its intended purpose is through adaptation. Furthermore, preservation of heritage buildings is thought to be a major force toward revitalization.
4. Multicriteria on evaluating whether the buildings are viable for adaptive reuse
4.1 Existing studies for assessing adaptive reuse potential
The intricacy and dynamism inherent in determining adaptive reuse strategies stem from the intricate interplay among various stakeholders and the diverse array of considerations that necessitate careful deliberation. For example, whether the structural capabilities of the building align with updated functional requirements or meet current health and safety standards; whether or not its energy performance is sufficient; whether its systems for drainage, electricity, and mechanical is adaptable to change; whether hazardous materials are present; and whether its location is secure and convenient, among other considerations.
These uncertainties have the potential to extend the project's length while elevating its risk and expense. The promotion of sustainability led to a significant increase in interest in building reuse.
Ball (1989, 2002), for instance, examined the industrial property portfolio in the United Kingdom, together with determining the features of the structures that were repurposed or inhabited versus those that were vacant. According to him, the traits referred to potential for repurposing adaptively were found. The study helped to clarify the benefits of reusing buildings, but it did not offer a means of assessing clusters of buildings.
Love and Bulllen (2009) developed a framework for office buildings called NABERS (National Australian Built Environment Rating System). It focused on how well-performing old structures were environmentally. The main techniques were the occupants' survey and the checklist. Because the method only focused on specific buildings, which were unable to rank or compare buildings for reuse, neither the tools nor the underlying methodology are sufficiently ubiquitous. The buildings' artistic and social value were not taken into account. For buildings located within conservation areas, these values are crucial. The two technologies' occupant survey and checklist approaches are unable to handle long-term unoccupied historic buildings and subjective opinions.
A prioritized list of design techniques strategies called the AdaptSTAR model was created by researchers (Conejos et al., 2013), which was meant to serve as a manual for new design initiatives, evaluating them or recommending adaptive reuse during the early design phase. However, rather than focusing on already-existing historic buildings, the evaluation's goals are for new design projects.
The subsequent researchers (Bullen and Love, 2010, 2011; Love and Bulllen, 2009) discovered characteristics that influenced decision-making about adaptive reuse within the setting of Australia. Three groups were created from these variables: regulation, capital investment, as well as asset state. More empirical study is required to see whether these models are applicable in other situations. Historic structures are priceless reminders of traditions, values, and
rituals that enhance their communities and should be conserved. These buildings were constructed according to the specifications, keeping in mind their intended use and location. On the other side, quick physical modifications could eventually affect a building's capacity to fulfill its main function. The rising social, economic, and environmental obsolescence of the buildings is considered to be the main source of these changes. Actually, the values are gradually being eliminated, but the adaptive reuse strategy makes it possible to bring them back. The process of figuring out whether historic structures with distinctive architecture specific to a given time and region have a potential future and contribute to the local economy is another definition of reuse. The term "adaptation" refers to the greatest level of modification in the primary building's usage while maintaining its structural integrity. The primary obstacle to adaptive reuse is the dearth of thorough research to fully utilize buildings' functional potential at the right moment.
An instrument for evaluating historic structures' potential, usable life, and physical life is the ARP model. By itself, this raises the building's sustainability on the social and environmental fronts and aids in public entity budget control. This method meets the requirements for long-term sustainability in terms of the environment, society, and economics by making it easy to identify which historic structures are most suitable for adaptive reuse before they are demolished. The ARP model provides a complete approach, unlike other models that may focus on specific attributes or only specific types of buildings.
It assesses whether a building is suitable for reuse at any stage of its life cycle, which is crucial for historic structures since over time, different factors like structural integrity and cultural significance become more significant.
The ARP model uses multi-criteria assessment tools to apply a multi-criteria approach that considers factors such as social benefit, environmental impact, and economic viability. This is crucial for projects involving adaptive reuse since it requires striking a balance between preserving historic integrity and ensuring modern utility and safety. Long-term viability specifically considers the length of time between a building's functional life and its physical lifespan, giving priority to structures with a longer potential lifespan for adaptability. This emphasis encourages sustainable development and helps with more effective resource targeting by prolonging the useful life of existing structures and lowering the need for new construction.
By determining the ideal moment for interventions, the model can offer prompt interventions and help in making choices about when to launch adaptive reuse projects in the future. In addition to safeguarding cultural assets and possibly saving money on future, more extensive renovations, this can prevent historically significant buildings from being demolished or falling into ruin. Additionally, the method prioritizes social and environmental benefits when assessing a building's flexibility. It backs the evaluation of how repurposing buildings can minimize environmental effects by reducing material waste and
increasing energy efficiency, which would advance social and environmental sustainability. Furthermore, it has practical applications in various contexts due to its broad applicability to a wide range of buildings and environs, which increases its value in various geographic and cultural settings. This flexibility is essential for heritage conservation work since it allows for the consideration of various architectural styles and historical values. As such, the model has been chosen for this paper's discussion.
4.2 Significance and innovation of ARP model
This model can help find and justify historical buildings that are appropriate for adaption before they are destroyed or fall into ruin. Given the particular restrictions of projects and the interests of stakeholders, it is possible to objectively analyze the harmony of initiative viability, environmental effects, along with social benefits. In this method, projects with a high potential for adaptive reuse can be ranked. It is important to construct the assessment tool to find out if adaptive reuse is possible. Historical buildings having a long duration between their useful life and physical life are preferred over those with a short duration between their current age and physical life. When a building's usable life approaches its current age, it should be decided quickly to consider adaptive reuse possibilities. This model assists in better targeting property resources by identifying buildings that are eligible for adaptive reuse and
grading them based on their actual ability to benefit communities. In order to screen through the current building stock and pick properties that have high rest value for potential adaptive reuse, it employs a tried-and-true multi-criteria approach. Designers might then focus attention on the initiatives that have the most chance for adding value. Enhancing the adaption of already-existing historical buildings improves their performance in the relative field of sustainability, places less strain on the environment, and makes better use of resources Repurposing buildings that have exceeded their original use but nevertheless significantly contribute to the urban landscape is another way that national heritage is preserved. This is particularly relevant with building environmental evaluation, which is important because reusing buildings has the fundamental environmental benefit of conserving the energy and water linked with the corresponding new materials required for a completely new construction.
4.3 Assess adaptive reuse potential utilizing the ARP model
Historic structures need continuous upkeep and rehabilitation. Naturally, depending on the building's physical state, the modifications may involve demolition or alteration. Structures with a high rate of obsolescence or that are probably going to be demolished soon have less possibilities for reuse. Sometimes, a building's new function does not ensure that its reuse will be successful. The ARP model is used to identify the important aspects in
determining the building's potential for its future use, to ascertain the building's potential for adaptation and its useful life.
This model is applicable universally to all nations. With the aim of determining a building's usable life, the model needs to know its current age and its expected physical life, both expressed in years. A review of technological, functional, social, legal, economic, and physical obsolescence is also necessary.
Obsolescence is promoted as an appropriate approach to lower anticipated lifespan to determine the building's useful life objectively. Additionally, it is the inevitable process of the building's quality deteriorating as a result of social and environmental variables. An approach is presented that uses this data to generate a percentage-based reuse potential index. Therefore, existing buildings can be graded based the potential they provide for repurposing According to the model, planning should begin as soon as a building reaches or beyond its useful life.
An analysis of maintenance performance and policy can be used to evaluate physical obsolescence. Inadequate maintenance of building parts effectively reduces useful life.
A building's proximity to the center of urban area or central business area might be used to calculate its economic obsolescence. The useful life is significantly decreased given that it is situated in an area with little population density.
One way to judge functional obsolescence in architecture is to look at how
flexible the design of a building is. Provided layouts of the buildings are not adaptable, their useful life is substantially shortened.
The building's operational energy consumption can be used to quantify technological obsolescence. A building's useful life is significantly decreased if it requires a lot of energy to maintain tenant comfort. Building functions and market share are related, and this relationship can be used to assess social obsolescence. If the viability of a structure is dependent on outside revenue, useful life is essentially decreased.
Legal obsolescence can be measured based on how well the original design was done. Buildings that are poorly designed and built effectively have a shorter useful life.
Table 1 Scopes of application of the formula and meanings of the parameters formula explanation
Source: Langston,2008
Source: Langston,2008
The useful life is calculated using this formula.
This formula is used to calculate the potential ARP range.
Source: Langston,2008
Source: Langston,2008
Lp stands for life expectancy (years).
The formula is utilized to determine the highest possible amount of ARP.
This formula determines the lowest possible quantity of ARP.
O1 O6, physical obsolescence; economic obsolescence; functional obsolescence; technical obsolescence; social obsolescence and legal obsolescence
Lb is the building's current age expressed in years.
Effective building age (ELb) is measured in years, while effective usable life (ELu) is measured in years.
Effective useful life (ELu), effective building age (ELb), and effective physical life (ELp) are calculated by multiplying their respective values by 100 and dividing by Lp. This allows for a maximum scale of 100 for the x and y axes.
Source: Langston,2008
The potential for adaptive reuse of a building is assessed according to its suitability, and this potential is represented as a percentage in an index.
Structures with a high index have the most potential, whereas those with a zero index have none at all. ARP values above 50 are regarded as having a strong potential for adaptive reuse, whilst values between 20 and 49 denote a moderate potential, values between 1 and 19 a low potential. Zero as the value of adaptive reuse potential indicates no potential. A value of 85 or higher would strongly imply that planning should get underway.
4.4
Summary and analysis
For existing buildings, the ARP model offers a sensible and straightforward way to access both adaptive reuse potential and effective useful life.
Results from this method are thought to be reasonable and practice-reflective. It offers a range of values that fall within predetermined bounds, making ranking and prioritization possible. It acknowledges that as building age approaches its useful physical life, potential diminishes.
Still, it's unclear what should be done with the rankings. Mostly based on the innate ability to sustain physical life after the completion of useful life, the rankings should identify buildings with a high potential for renovation. The age of the building to some degree has some impacts on its potential. A few usage cases and recent research demonstrated that, with the purpose of properly understanding a building's contribution, reuse decisions must consider economic, environmental, and social values. Making decisions based solely on financial considerations will result in bias.
Regarding the above-mentioned concerning, it is true that determining value for interest in development projects is frequently correlated with financial return. However, other concerns are also pertinent, especially, with regard to social infrastructure initiatives, and some of them are growing in importance.
Functionality and resource efficiency, for instance, are crucial considerations when evaluating sustainable development within a larger social framework. Because there is not a single criterion that can fully address every issue involved in these kinds of complex judgments, using multiple criteria to make decisions has many advantages. Social costs and benefits, such as those pertaining to heritage and environmental impacts, must be incorporated into the evaluation process Additionally, a plan must be created that takes these aspects into account in actuality Benefits and expenses to society are not to be undervalued. Since social costs and benefits have minimal bearing on financial problems and do not decrease significantly over time, they should not be discounted in conjunction with conventional cash flows. It's possible that in the future, environmental challenges will be more important than they are now.
5. Current case studies and abstracting the factors may be considered during the decision-making process of their new functions
5.1 Principles for the selection of new functions
The suggested new usage needs to be suitable, concerning about maintaining cultural relevance of historic fabrics with the intention of conserving heritage building's cultural worth, which requires determining the context-relevant purposes that are most applicable So as to avoid providing incorrect or incomplete information for future generations, while historical buildings are converted to new purposes, the original architectural characters must be preserved together with any modifications.
To determine the best course of action for the adaptive reuse projects, the choice of new use must be supported by a methodical and rigorous analysis
During the process of making decisions, all relevant elements ought to be taken into account to ascertain the most appropriate function for the structures when evaluating the different aspects of adaptive reuse.
The preservation of historic buildings requires significant financial investment, therefore, in order for reuse projects of existing buildings to be effective, the structure must be physically, socially and economically sustainable. Various parameters must be examined when making decisions about adaptive reuse, such as market trends, architectural assets, heritage value and location.
Adaptation of historic buildings is a difficult process as there are many factors that influence the decision-making process. An integrated approach is necessary for any project to redevelop an existing structure to be successful. The condition of a historic building must be assessed before new uses are permitted and management plans and conservation plans should work in
tandem. Careful consideration should be given to the existing structure when reusing a heritage building. When applying for adaptive re-use for a change of use, the exterior and interior of the building should be thoroughly assessed and an extensive evaluation should be carried out. In addition, the appropriate adaptation of historic properties is a difficult process that requires participants to have a thorough understanding of how to determine the best course of action for a building in a given location and time. When making decisions about adaptive reuse, it is important to conduct a thorough analysis to determine the optimal function while considering the various factors of adaptive reuse. It is important to recognise the value of built heritage as a dynamic asset rather than a pile of stones stacked on top of each other that needs to be preserved. Along with their physical characteristics, heritage buildings have value and meanings that should be accounted for. Before pursuing development that, considering the structure's new purpose, is considerate of it, developers should first understand why the property has been granted heritage status. The impact of a heritage-based adaptive reuse project for a building should be kept to a minimum intervention. This includes discouraging facadism, which is the alteration of interior layouts, functional spaces, and the complete removal of patterns with significant historical significance, leaving only the façades unchanged. The new work should not be a shoddy reproduction of the building's original historic style, but rather clearly identifiable as contemporary, and it must
seek a new purpose for the structure that blends in with the surrounding community.
Maintaining the building's physical integrity alone is insufficient, it also needs to maintain its originality by assigning suitable uses and functions. Making the right decisions is crucial to any project's success, but it's more important when working with historic ones. Making decisions requires careful heritage management plans and the application of long-term protective measures when it comes to historical buildings.
5.2 Modeling the process of determining decisions
The model suggests a set of procedures to be followed while making decisions on building’s rehabilitation. It can be used for the majority of historic building types that are vacant, misused, or abandoned. The approaches to adaptive reuse may vary in other contexts due to planning and policy concerns. However, by taking into account the plannings and policy challenges of the relevant locations, the suggested approach could be altered and applied to produce adaptive reuse strategies for various historic building types in various contexts. With the model, new strategies to heritage buildings might be proposed. It can also be used to determine issues with decision-making and assess whether the new use for historical buildings that have been repurposed is appropriate in cases where projects of adaptation have failed. Given the current states of
historical buildings to the development of new plans, there are five steps that need to be taken.
Although the model suggests an interpretive method, the ultimate choice is dependent on various factors, including the stakeholders involved in the adaptive reuse projects within the historical building's environment, relevant context policy issues, etc. These aspects can be taken into consideration while interpreting and making the ultimate judgment.
Fig.1. framework of decision-making process identifying stakeholders in this process (who will make the decision and for whom)
Customer creator financier controller for whom→target users
examination of the current elements initial purpose physical traits historical significance requirements of the communities impletion of some conservation actions that are needed for adapting new functions preservation refurbishment maintenance rehabilitation
restoration renovation consolidation reconstruction
This step can combinate any of them.
evaluation of the potentials of adaptive reuse architecture economy function environment Policy society culture
Mainly assessed by ARP model. making a decision about functional modifications
Consistent with the initial use Add new features while keeping the original ones Completely abandon the original function replacing by a totally new one decision makers' ultimate choice plan of management for its eventual use (for sustainability)
Source: author
5.2.1 Definition of the actors
The actors participating in the process of making decisions are the focus of the first stage. Stakeholders who will influence the outcome of new functions and engage in this practice are referred to be actors. Users, producers, investors, and regulators are the four groups into which these actors have been divided.
The project actors should be identified during the decision-making process because they are subject to change with each project. Contextual utilizers and original utilizers together make up the category of users. Although user input is crucial to decision-making, adaptive reuse programs typically overlook it. The people who used the building for its original purpose are its original users. Even though they may not be found who once used these old buildings, their contributions ought to be included while choosing new functions Furthermore, the district's present involved parties can be considered as situational users
Users' thoughts and suggestions for the future usage of the relevant constructures are supposed to be considered.
Individuals who plan and implement conservation initiatives are called producers. Depending on different projects, it may comprise architects, designers, engineers, restoration professionals, and other experts of relative fields. Since producers are the subject-related experts, it is advisable to consult their thoughts before hiring them, even though investors typically do so after deciding on a new use.
Local governments and planning authorities are examples of regulators. These authorities may be departments of governments, municipalities, or organizations that deal with heritage conservation. They are the ones who set the rules governing conservation and restoration initiatives, approve applications, and oversee the projects. These authorities may have different titles and missions in different nations. The engagement of regulators in procedure of function-
selection is crucial in avoiding needless modifications to historically significant structures.
According to a few recent studies and instances, the primary decision-maker for historical buildings is the investor In other cases, such as those involving listed structures, authorities play a supporting role.
Stakeholder input was considered essential to guarantee that the principles of sustainability were included with the objective of adaptive reuse to be successful. Adaptive reuse is typically avoided by owners and developers who view developed assets as a temporary investment.
5.2.2 Analysis of existing fabric
An examination of historical buildings, which comprises determining the architectural original functions, physical attributes, value, and district needs, is the second phase. Finding original use is crucial to choosing the right course of action.
With the aim of choosing suitable new functions for a historical building, it is essential to analyze the physical aspects of architectural heritage.
Considerations should be made for several aspects while evaluating historic buildings’ potential for regenerative building strategies: the building's location, and convenience; its physical dimensions; its structural system; the building's construction techniques and the existence of dangerous materials; the number of stories; its style as well as constructional period; its physical conditions; the
building's spatial organization which can be used to evaluate the historical buildings’ abilities to adapt new functional areas and purposes; the facade characteristics; the state of its electrical systems; the building's potential to meet accessibility requirements; their abilities to create a secure and safe atmosphere; and the building's energy-efficiency of existing fabrics such as walls, windows, and roof, and so on. Before choosing a new function, a thorough analysis of these aspects should be done. Determining the historic values is another crucial decision-making component that has a direct impact on the choice of new function. Finally, for the purpose of determining proper usage, the needs of the district should be identified. The district should be considered comprehensively while evaluating the historical buildings rather than treating them as a singular entity.
5.2.3
Deciding conservation actions
The final stage is to determine what interventions are required for the historical buildings. As it is a variable which is going to influence decisions in subsequent stages, this action was designated as the third phase, which ought to be determined immediately following the assessment of current fabrics of buildings. The choice made for new usage will be straightaway impacted by the building's current physical states. All these factors for different conservation activities ought to be considered since they will have a direct impact on the decision
about the new functions. As a result, decisions about which kinds of intervention will be conducted should be made early in the process.
5.2.4 Definition of potentials of historical buildings’ conversion
Finding the historical buildings' potential for reusing is the fourth phase. Potential can be defined as ability to reap benefits from adaptive reuse. Understanding the building's potential is crucial to creating solutions that will allow for its sustainable adaptive reuse. Some possible aspects for consideration of this issue can be from economy, functions, environment, policy, society, culture and physicality
5.2.5 Choosing appropriate new functions
The new usage methods should be decided upon once all decision-making procedures have been evaluated. The first option is to continue using the building for its intended purpose while making the required modifications to make it meet modern needs. This strategy is used when the building's originality could be harmed by changing the use and all heritage elements are highly valued. The building's modification for mixed use is the second approach. This strategy preserves the building's original function while adding new uses to ensure the historical structure's long-term viability. The third method involves giving the building a completely new function. Considering that it is dependent upon historical building's values, not all historic building categories can be
restored using this approach casually. Regulation obstacles prevent this means from being used for some occasions, for example, while conducting reuse strategies and apply new functions to religious buildings.
The experts should draft a management strategy as the last stage following the ultimate choice on new use. The management of heritage buildings is an issue in many adaptive reuse projects. The profits made from the preserved buildings should go toward future structural maintenance and repair. Appropriate management plans and techniques for adapting to cultural heritages sustainably are lacking. The primary goal should be to maintain the building's originality, values, and context. What’s more, the building's economic sustainability is crucial to the built heritage's future.
6. Some criteria or aspects can be used to evaluate the success or reasonableness of new functions
An essential component for a project or organization to fulfill its objective is known as a critical success factor. To make sure adaptive reuse projects benefit the communities and stakeholders, it's important to identify the variables that affect how well they're executed. Finding the critical success factors for adaptive reuse can give property owners, constructors, and other important stakeholders the information they need to make sure a project achieves successful completion
There are several obstacles of adaptive use that have been highlighted, including the presence of hazardous materials, deteriorating structures, building regulations, and the current layout. When assessing CSFs, these obstacles must be recognized and taken into consideration.
6.1 Economic factors
Time is a critical component in the construction process from an economic standpoint. When opposed to the process of dismantling and constructing renewed buildings, the project of renovating for new purposes can be completed more quickly. In adaptive reuse projects, a shorter redevelopment period results in lower construction costs, which have to be taken into consideration while making decisions. As many building components and materials are already on site, converting and repurposing an existing building typically costs less than building a new one. The addition of value to current buildings that can be attained by employing effective adaptive reuse means. Stated differently, the extra value extends beyond the historic structures and into the adjacent neighborhoods.
It is indisputable that a desirable location is crucial to the financial success of reuse initiatives. Moreover, a growing number of job opportunities, revenue from the tourism sectors, self-sufficiency through a possible market for new usage, and the fact that the project's benefits ultimately exceed the costs of reuse are all factors that support economically successful adaptive reuse projects.
6.2 Authenticity and historic factors
The most effective adaptive reuse cases respect and maintain the historical significance of a historic building without distorting its unique character while also including a fresh contemporary layer that increases future worth The following briefly describes the fundamental criterion guiding the addition of new purposes to projects involving adaptive reuse: first and foremost, the new use should have as little effect as possible on the building's historical value and history. Preserving as much of the original elements as feasible can lower construction costs while also adding to the building's characters. Reducing a building's structural alteration also lessens its exposure to latent conditions throughout the constructing phase, which lowers the likelihood of unforeseen expenses. Thirdly, the new use should improve the local spirit. Fourth, it should preserve the building's culturally significant structures. And fifth, it should offer a matched and modern essence which may benefit next generations. Preserving values expressed by heritage buildings is generally the ultimate goal of heritage maintenance, rather than material conservation. Weathering and slight deterioration can occasionally be viewed as having "age value", as they demonstrate the old building's authenticity, enduring quality, and timeless quality. Avoiding attempts to replicate inauthentically aging-related material transformations.
6.3 Architectural (physical) factors
By using an adaptive reuse mode to revitalize existing buildings, the built environment can be made more aesthetically beautiful and productive. Since architectural historic aspects are important, paying noticeable attention to establish the appropriate level of alteration that will preserve the characters of historical buildings with the least amount of intervention is crucial. Reuse projects should prioritize materials since their "value of age", inherent beauty and aesthetic attributes in their degradation are integral to the historic characters of the buildings. In addition, the newly added elements and the inherent characteristics of historic buildings should have a significant harmony for aesthetic coherence. The building's novel architectural designs are not supposed to mislead original constructions during reuse process; rather, the modifications must be distinguishable, in addition, reversible for any future modifications. The repurposed project with adaptations should operate as an initiator of the neighborhood's urban modernization and the physical enhancement of the surrounding properties. Creativity becomes especially important when working with existing historical structures and trying to respect their current circumstances, which can successfully integrate new and old components and innovates to satisfy the requirements of the present into current buildings
6.4 Functional factors
Finding a harmonious blend of the building’s old and new functions is essential since an adaptive reuse project's success may be assessed by how well the new use succeeds. It was proposed that the more closely these functions match each other, the easier it is to finish the adaptation process. If the appropriate historic building has been chosen, and if it meets the functional requirements well, then not too many modifications are required to make them truly outstanding. It is undeniable that selecting a proper function is crucial The original use and the new function must be compatible. Additionally, the new use of heritage buildings should maintain a connection with its original form and historic characters. Without people, historical constructions are meaningless, thus it is important to think about how to best engage users by designing new activities inside historical buildings and tailoring existing ones to meet their requirements, goals, and satisfactions.
6.5 Structural (technical) factors
When it comes to structural elements, old structures frequently separate from modern construction standards. Therefore, with the intention of supplying a suitable scale of safety for users, it is essential to upgrade structural components of historical buildings. Actions that should be considered are, such as, enhancing the load-bearing structure's technical performance and implementing renewable technologies to enhance indoor environmental quality, and enhancing the historic or current building's technical and structural states in
order to proper restoration for contemporary use. It is crucial to recognize that, while dealing with buildings with historical values, it is essential to evaluate how the new technical system can affect artwork and materials, in order to create appropriate preservation measures.
6.6
Environmental factors
The factors that are mentioned in recent research include accessibility towards the structures as well as within the interior spaces. People are what keep buildings alive, and the way these individuals engage with the historic district's surroundings is an impressive factor. Other environmental elements include focusing on the local settings which include landscape and historic contexts, taking part in city regeneration strategies and advantages, and utilizing open and green areas to improve the quality of the environment.
6.7
Energy factors
By making use of existing buildings, adaptive reuse has a major positive impact on efficient energy usage and fostering the growth of an environmentally sustainable built landscapes. One crucial early step is analyzing the building's existing state for the purpose of energy efficiency and assessing the extent of restoration in relation to its heritage value. Selecting suitable building and energy-saving measures is the next important step. Along with other aspects that affect the energy efficiency of repurposing projects, the significance of the
building envelope and the application of maximal thermal protection measures to it, as well as the optimization of sunlight illumination and interior atmospheric condition through design, should be mentioned here.
6.8 Legislation
Legal considerations are an unavoidable part which include laws governing building codes, fire safety, legislation requiring safe, healthy, and user-friendly projects, and so on. Adaptive reuse strategies are set apart from new construction projects by extra-legal factors, namely local regulations and global agreements on conservation
6.9 Socio-cultural
aspects
People across the globe cherish their civilization, history legacies, and heritage landmarks. The conservation and usage of historical buildings improves people's perception of their relationship to immediate surroundings, public awareness, the sensation of belonging, emotional connection to the location. A well-restored historical site should enable individuals to reconnect with their cultural roots, fostering a sense of shared cultural roots and revitalizing the past. Adaptive reuse needs to take the community's and its users' requirements and preferences into account. A socially adaptive reuse project is supposed to enhance public spaces, maintain the area's identity, and foster a feeling of place. Due to their representation of well-designed details and materials, old
buildings are often linked to inherent social advantages and are essential to preserving the streetscape's appeal, giving neighborhoods characteristics, and projecting a positive image of the community. The socio-cultural success of reuse projects can be greatly influenced by increasing locals' awareness of the value of heritage and the benefits of preserving it, as well as by encouraging educational programs about the issue. The next step is to engage the community in planning, execution, as well as the process of making decisions of reuse projects, in order to better understand their needs and desires.
6.10 Management(decision-making) factors
It is crucial to consider a number of factors during the process of decision making regarding historical buildings. After engaging with many stakeholders, developing a heritage management plan is an important stage. This phase is crucial to accomplishing the project's goals. Effective collaboration between various stakeholders, or active involvement of stakeholders, as well as between stakeholders and the communities, is one of the key principles that have been addressed for the successful implementation of adaptive reuse. When making decisions, the interests, benefits of the stakeholders, new use of place, experiences, and memories should be taken into account, adhering to the fundamentals of effective management in adaptive reuse. The prominent role that efficient management plays in maintaining and improving the historical
environment, which is why it is crucial for the successful repurposing of historical sites.
6.11 Design
When starting an adaptive reuse project, all these elements can be included in the design process. In other words, these variables need to be considered throughout the entire adaptive reuse project planning and design process. Before beginning to create, the designers should ascertain what the client wants and identify any potential obstacles, only then can they proceed. Additionally, it may be argued that getting early suggestion is essential to a project's success, especially when it comes to assisting in overcoming obstacles that will inevitably arise, such as governmental laws that may obstruct the implement of heritage projects.
Architects may preserve the integrity of current buildings and structures by keeping their design team informed about the heritage value. This understanding makes it easier to incorporate design changes and remove or modify less sensitive sections. By using this strategy, more important regions are guaranteed to be saved. Understanding the scope of the latent conditions is essential to any design of an adaptive reuse project. Knowing the building's structure can help determine its constraints and reveal information about its underlying latent conditions.
The structural components may seem to be in decent appearance on the outside, but years of paint may have obscured their true conditions. Although latent circumstances were found to be harmful, they were also thought to be necessary for design to develop. Furthermore, it was determined that creativity was essential to success to meet the strict requirements of current codes, especially the concerning about safety. Moreover, owners and clients have superior information for crucial design choices, consequently, cost predictability when they know the extent of hidden circumstances that exist. Even if a building's function and design cannot always be perfectly matched, adaptive reuse is nevertheless feasible. The adopted design can satisfy the client's needs while enhancing the building's historical traits.
To summarise this section, the success factors can be categorized into three main groups in general: the first group is called conceptual success factors, and it includes factors of society, culture and authenticity that are connected to the ideals of initiatives involving adaptive reuse; the second group is referred to as operational success factors, which are related to architecture, physics, structure, energy, economics, law, and decision-making. The third group is determined by planning or design standards. There is a hybrid category, such as functional and environmental elements, that falls in between and is not entirely constrained by conceptual or practical definitions. Adaptive reuse's success includes both concrete and abstract components, operational and conceptual aspects, and qualitative and quantitative variables.
7. Conclusion
In order to ensure that the new functions given to the historic buildings and the new activities to be carried out in the functional spaces of the historic buildings are consistent with the existing spaces and architectural structures, this thesis focuses on the four aspects of the decision-making process: economic, environmental, social and cultural. This will be examined in a more scientific and comprehensive way through the ARP model.
This paper concludes from a literature review that adaptive reuse can preserve the physical and historical integrity of historic buildings, while at the same time significantly reducing waste and energy use to achieve the goals of a sustainable built environment.
This is because the reuse of existing historic buildings can effectively reduce the resources and time required for re-construction. Reuse projects are also considered to be more energy efficient and environmentally friendly than constructing new functional buildings. Successful reuse of historic buildings can effectively give back to the communities, preserve cultural identity and enhance the regional economy.
The ARP model is considered to be an effective tool in the process of evaluating the reuse value of historic buildings, which can help stakeholders to evaluate and classify the reuse possibilities of historic buildings according to the final results assessed by the ARP model, and help them to find out the
appropriate time for reuse. Furthermore, to a certain extent, urge the stakeholders to promote the preservation and reuse projects of historic buildings.
The model ensures that the historic building is preserved properly and appropriate new features are acquired to meet the needs of current and future occupants. The selection of new functions needs to be considered about a number of aspects, which may include the history of the building, assessment of associated values, structural integrity, and even regeneration of the cityscape. The decision-making process also emphasises close cooperation and direct contact between stakeholders, including architects, planners, legislators, users, and residents of the community in which the historic building is located, in order to reinforce the role of the utilisation project as a cornerstone of sustainable development and cultural identity, while successful reuse can be seen as an effective tool for the preservation of historic buildings.
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