Adaptive reuse is the reuse (or conversion) of an existing building for a purpose other than that for which it was originally built or designed.Arfa, F., Zijlstra, H., Lubelli, B., & Quist, W. (2022). Adaptive Reuse of Heritage Buildings: From a Literature Review to a Model of Practice. Historic Environment: Policy and Practice, 13(2), 148–170. https://doi.org/10.1080/17567505.2022.2058551 The adaptive reuse of buildings can be a viable alternative to new construction in terms of costs, aesthetics, and sustainability among other benefits.
Definition Adaptive reuse is defined as the aesthetic process that adapts buildings for new uses while retaining their historic features. Using an adaptive reuse model can prolong a building's life, from cradle-to-grave, by retaining all or most of the building system, including the structure, the shell and even the interior materials.Joachim, M. 2002, Adaptive reuse, Massachusetts Institute of Technology, Cambridge, Massachusetts, 1 Oct. 2011 This type of revitalization is not restricted to buildings of historic significance and can be a strategy adopted in the case of obsolete buildings.
Advantages of adaptive reuse Typically categorised under economic, social, cultural and historical, and environmental benefits. The most significant benefits of adaptive reuse of existing buildings include increased economic opportunities, urban regeneration, preserved cultural and historical heritage values, reduced landfill demolition waste, increased energy efficiency, extended building usefulness and cost-effectiveness, enhanced property value, improved life quality, reduced carbon emissions, and lower energy consumption. Some urban planners see adaptive reuse as an effective way of reducing urban sprawl and environmental impact. According to Yung and Chan, "adaptive reuse is a new kind of maintainable rebirth of city, as it covers the building's lifetime and evades destruction waste, encourages recycles of the embodied dynamism and also delivers substantial social and economic profits to the world".
Revitalizing the existing built fabric by finding a new use or purpose for obsolete buildings can be a wonderful resource to a community by "keeping neighborhoods occupied and vital". The reuse of older vacant buildings for other purposes forms a very important aspect of any urban regeneration scheme. Adopting the adaptive reuse approach for the redevelopment of older vacant buildings provides added benefits to the regeneration of an urban area in a sustainable way, through transforming these buildings into usable and accessible units. The adaptive reuse strategy would also enable the local authority and owners of older vacant buildings in urban areas to minimize their economic, social and environmental costs, in a quest for a continued urban expansion and development.
Built heritage conservation through adaptive reuse could therefore be used to promote sustainable historical and cultural development of urban areas.Aigwi, I. E., Egbelakin, T., & Ingham, J. (2018). Efficacy of adaptive reuse for the redevelopment of underutilised historical buildings: Towards the regeneration of New Zealand's provincial town centres. International Journal of Building Pathology and Adaptation, 36(4), 385-407. Parameters to prioritise historical buildings for adaptive reuse and the characterisation of adaptive reuse stakeholders are also noted.
Architectural beauty and cultural heritage: According to Zaitzevsky and Bunnell, old buildings physically link us to our past and become a part of our cultural heritage; they should be preserved because of their "architectural beauty" and the "character and scale they add to the built environment." A majority of historical buildings provide physical links and the progression of cultural evidence to the past. Cost savings on building material: Adaptive reuse involves the refurbishment of existing building members, which tends to be a relatively labor-intensive process and relies less on purchasing and installing many new building materials. Cost savings on demolition: Demolition costs may range from 5% to 10% of the total cost of new construction. This expense is often overlooked by many building owners. Some urban areas have strict building safety regulations and may not allow the usage of a swinging ball and other more efficient demolition techniques. Under these circumstances or a desire to reuse and recycle materials from the existing structure, buildings must be demolished piece by piece, which might be more expensive and often is more time-consuming. Saves time: The total time required to renovate an existing building is generally less than the time required to construct a comparable amount of floor space in an entirely new building. A major advantage of renovating an existing building is that a refurbished portion of the building becomes suitable for occupancy before completion of the whole project. This provides as a notable advantage for those worried about cash inflow or space shortages while the rest of the project undergoes construction. Decreased public and social costs: Urbanization and urban sprawl cause several harms to our planet and the society. Lack of adaptive reuse of existing built assets can lead to dislocation of residents, economic decline and disruption of community life, eventually leading to abandoned and obsolete neighborhoods. Buildings and the development around them soon become the heart of a community upon which people's life depends. Regular maintenance and reuse of existing structures can help communities avoid the trauma caused by dilapidation, abandonment and clearance. This can help reduce the dislocation of residents, economic decline and disruption of community life, eventually leading to abandoned and obsolete neighborhoods. Old buildings are often found in fully developed neighborhoods where public amenities like sewers, water lines, roads, etc. have already been established. Adaptive reuse means that governments and municipalities have less infrastructure to build and maintain. In a survey conducted by researcher Sheila Conejos, several architects, developers and building stakeholders were asked about their opinion on the social implications of adaptive reuse of existing buildings. Most respondents thought that adaptive reuse is important to the society because old buildings are critical to the image and history of a society. They agreed that historical buildings add to the aesthetics of a townscape and should be preserved and reused. Environmental benefits: Modern building systems have high life-cycle costs and operational energy costs associated with them whereas traditional masonry and stone buildings are more climate-responsive. A significant environmental benefit of reusing built assets is the retention of the original buildings "embodied energy" in the building materials. The adaptive reuse of existing buildings can be adopted to facilitate climate change mitigation and is generally considered the most sustainable approach to developing and using a building.
Challenges Typically categorised under building regulatory requirements and governance, financial, management, and complexities and uncertainties challenges. The most significant challenges of adaptive reuse of existing buildings include structural integrity issues, compliance with building code regulations, government anti-adaptive reuse policies, lack of awareness, high maintenance cost, uncertainties surrounding existing building information, lack of incentives, and lack of decision-making tools and stakeholder participation.
Predicting successful reuse According to Chusid's "urban ore" concept, existing buildings that are fast approaching dilapidation or disuse are a "mine of raw materials for new projects". Shen and Langston built upon Chusid's idea and said that "an even more effective solution than raw material recovery is adaptive reuse". They studied that "a huge focus on economic factors alone has led to the destruction of buildings well short of their physical lives". Shen and Langston developed an integrated model for the assessment of adaptive reuse potential (ARP model) in 2008 by comparing case studies of one urban and one non-urban setting. The basis of this model lies in that "opportunity rises and falls within the confines of a negative exponential decay function linked to a building's physical life expectancy".
According to their study, a building reaches its maximum potential for adaptive reuse at a point when the building's age and its useful life merge or meet. At this point, the building's adaptive reuse potential is either an upward curve or a downward curve which can determine whether the potential is high, medium or low. The adaptive reuse potential calculator establishes a "predicted useful life" of a building by considering a series of physical, economic, functional, technological, social, legal and political characteristics. These characteristics are used to derive an "annual obsolescence rate" and "environmental obsolescence". These outcomes are necessary to determine an optimum point at which adaptive reuse intervention should occur.
An algorithm based on a standard decay (negative exponential) curve produces an index of reuse potential (known as the ARP score) and is expressed as a percentage. This decay curve in buildings can be used to establish an ARP score, which is expressed in percentage. Cities can rank their existing buildings as per their adaptive reuse potential and this data can be used by government authorities at any point in time. An adaptive reuse score of 50% or above is considered high. A low ARP score is anything below 20%. Anything between that range is considered moderate. Shen and Langston devised this concept of ARP as "rising from zero to its maximum score at the point of its useful life, and then falling back to zero as it approaches physical life".
AdaptSTAR is a 2013 model to facilitate adaptive reuse projects and has also been shown to be a good predictor of a successful project along with the ARP model.
A 2023 literature review identified some key factors for whether an adaptive reuse project would be a success. Architectural factors include whether the project minimizes intervention in the character of the structure, that new elements are compatible with the building without trying to pretend to be old, whether the interventions can be easily modified or reversed, maintain aesthetics such as the beauty of aging characteristics of a building, embrace creativity in the use of space while remaining functional. Structural factors emphasize the importance of extending the lifespan of the building among other practical factors. Cultural factors focus on the ability of the building to contribute to a sense of place and community pride, attracting the interest of the community in participating in its new phase of life, while improving the quality of life of its users. Economic indicators of success include whether land values have increased as a result of the project, shortening the construction period, saving on material costs, and helping develop local craftsmen and restorers, any boosts for tourism, and whether the tangible and intangible benefits outweigh the costs. In addition to environmental and energy considerations, there are authenticity and historic factors, including being able to tell the story of important events, maintain the congruity of a historic streetscape, and identifying and prioritizing the preservation of the features with the most heritage value.
Methodology Adaptive reuse projects are, in many ways, different from conventional new construction projects and must be planned and managed differently.
Building condition assessment