The relevance of facilities management practices in the built environment has been recognised for decades. The global facility management market exceeded $1 trillion in 2022, may hit $2 trillion by 2027, and is projected to reach $119.4 billion by 2030 [1]. The growth trajectory has been attributed to global trends including increasing investments in the real estate and construction industries, cloud deployments due to COVID-19, prominent remote working, and outsourcing trends [2]. The facilities management sector contributes towards the realisation of many sustainable development goals (SDGs) ^[3][4][3,4]. As a key component of the built environment and the services that help maintain and run the infrastructure, the facilities management industry plays a crucial role in meeting environmental challenges and organisations’ and stakeholders’ obligations (core and non-core activities) [5].

Facilities management integrates concerns from people, workplaces, and resources. Adequately managed facilities help to save on the costs of managing both the premises and equipment and boost employee morale while elevating their efficiency and engagement at the workplace [2]. With rising industrialisation, crime risks, the need to adopt a personalised, safe, and hygienic environment for employees, and the growth of security and technology awareness, new directions for sustainability have been the focus of more studies in the built environment. Moreover, with the tremendous rise in the use of fourth-revolution technologies, the transition of facility management over the years has altered the way enterprises operate [2]. Thus, the evolution of real estate models and increased focus on IT infrastructure, improved employee engagement, and health and wellness, while ensuring environmental sustainability, impact facilities management practice.

Consequently, sustainability concerns in facilities management have received increased attention in academic research. Concurring with this view, Opoku and Lee [4] edited and published twelve papers in a recent special issue of the Sustainability journal, titled “The Future of Facilities Management: Managing Facilities for Sustainable Development.” In their editorial piece, the importance of sustainable facilities management (SFM) to cater for the future in relation to the SDGs was emphasised. On their part, in their review of the evolution of FM, Bröchner et al. [6] expressed that opportunities for FM research are partly concerned with sustainability, combining environmental and social aspects, and advocated that policies and schemes for sustainable buildings should be more clearly linked to sustainable FM. Therefore, research collating new sustainability perspectives and principles is relevant to ensuring that key issues are not omitted in decision-making, planning, and forecasting for the future.

Previous studies have been undertaken on facilities management and incorporating sustainability perspectives. However, some have focused on developing countries ^[7][8][9][7,8,9], have a singular focus, for example, outsourcing [10], a safety management framework [11], life cycle assessment and energy consumption ^[9][12][9,12], and green leasing [13]. Further, studies that acknowledge the relevance of attention to public facilities have a limited focus on sustainability. For example, Galamba and Nielsen [14] focused on capabilities for public in-house facilities management geared towards social sustainability, while Ighravwe and Oke [15] and Mewomo et al. [16] paid little attention to different aspects of sustainability in their studies on factors that affect facilities management practices/approaches in public and private buildings in developing countries (Nigeria and South Africa, respectively). Similarly, Ganisen et al. [17] examined FM considerations to achieve sustainability (environmental, economic, and social) of building facilities, while Lee and Kang [18] evaluated innovation characteristics as predictors for SFM adoption; thus, they did not explore sustainability principles relevant to FM in the built environment.

From the above, it appears that there is no consensus on the sustainability principles to ensure maximal benefits in public facilities and buildings. This view was supported by Collins et al. [9], who opined that little consistency exists on how to bridge the gap between SFM and sustainable buildings. Further, most studies have used case studies or surveys to examine SFM variables and contexts. Few studies have systematically analysed and visualised the trends in facilities management sustainability research. According to Mendes et al. [19], existing evidence can be identified and updated through a systematic review where the topic is relevant and topical, and new research is continuously emerging. 

Therefore, a sequential explanatory mixed-method review entailing scientometric and content analyses was used in this study to map and analyse the knowledge paths to make them visible and understandable within the bigger picture of sustainability research [20]. The focus was on the built environment, which contributes greatly to energy consumption, accounting for 36% of final energy use [21]. Additionally, buildings in most developed countries, for example, the United States (US), consume 88% of portable water supplies, 68% of all electricity, 12% of freshwater supplies, 40% of raw materials, and are responsible for 20% of solid waste streams (US Green Building Council, cited in Darko et al. [22]). Although sustainability is not only environmentally inclined, the concern is great and can be a starting point for building on other elements, including social and economic. Moreover, assets and buildings account for most of the energy and material use in society ^[22][23][22,23]. 

2. Sustainable Facilities Management

Facilities management balances three aspects, including human resources, people (employees and employers), human resources and sociological aspects, work activities and resources (productivity and costs), and work environment (architecture and engineering) [12]. The function is responsible for the systems and processes that determine areas such as energy management, utilities performance, environmental and waste management, and recycling practices [24]. It is practised in various sectors/industries where manufacturing, production of physical structures, and operational/administrative activities are involved. Its roots lie in the custodial role of a building caretaker concerned with operational issues of maintenance, utility management, and costing but have evolved as the nature of businesses has moved from core competence to critical business and support services; thus, workplace and productivity concerns ^[25][26][25,26]. Moreover, work is no longer a place but an activity that can be conducted anywhere [5]. Due to the changing nature of FM, facilities managers are increasingly engaged with the evolving sustainability agenda and developing sustainability policies within their organisations [24]. Facilities management contributes to the realisation of SDG 6 (sustainable management of water and sanitation), SDG 7 (clean and affordable energy), SDG 9 (sustainable and resilient infrastructure), SDG 12 (responsible consumption and production), SDG 13 (climate action), SDG 15 (life on land and biodiversity), SDG 16 (peace, justice, and strong institution), and SDG 17 (partnership for the goals) ^[3][4][3,4]. These underlie the Brundtland Report’s definition of sustainable development as “development that meets the needs of the present without compromising the ability of future generations to meet their own needs” [27]. Therefore, SDG initiatives aim to develop meaningful action and progress in sectors that will still be critical to humanity in the future. In this context, sustainability was identified as one of the key areas in which FM professionals must develop their capabilities to meet the challenges, demands, and opportunities for sustainable development [3]. The SFM concept integrates FM and sustainable development by adopting technology and innovative business practices that balance the social, economic, and environmental impacts of business decisions [4]. It broadly encompasses flexible design and renovations to enhance building longevity, site development to promote liveable communities, waste management, energy efficiency, thermal comfort, indoor air quality, water reuse, use of environmentally friendly materials, and a circular economy through recycling practices during construction, demolition, renovation, and occupancy [18]. Sustainable facilities management aims to ensure workspaces have a minimal or positive impact on the environment. Opoku and Lee [4] provided definitions and explanatory notes on the significance of incorporating sustainability into facilities management. Fauzi et al. [28] argued that in addition to the maximisation of economic value and minimisation of economic and social costs, sustainability has become a strategic imperative for businesses as they increasingly recognise that aligning business operations with sustainable ways adds more value. Managed proactively, a SFM service can reduce costs and provide long-term value ^[29][30][29,30]. Sustainable facilities management is important as typical buildings consume more resources and energy than necessary, negatively impact the environment, and generate lots of waste ^[18][23][18,23]. Other literature has highlighted the importance of basing FM research on an understanding of the fundamental forces that shape change and long-term sustainability, for instance, digitisation, proptech, and post-pandemic consequences ^[6][31][32][6,31,32]. With the increase in wellbeing and ergonomic concerns, given the recent incidence of the COVID-19 pandemic and work-from-home adjustments, the employees and society have become the main concerns, leading to increased interest in public facilities management. Therefore, the adoption of sustainable practices can help in addressing FM challenges and simplifying its function at different levels (strategic, tactical, and operational levels) ^[3][4][3,4] and in regard to various principles.