Exploring the Interrelationship Between Sustainability and Quality of Life in Urban Design: A Mixed-Methods Analysis of Shared and Distinct Indicators

Abstract

Over the past two decades, sustainability and quality of life (QoL) have become foundational concepts in the design of buildings and urban spaces. Due to their strong interrelation and shared emphasis on human well-being, distinguishing between these concepts has proven challenging. While numerous studies have investigated sustainable urban design and QoL, inconsistencies remain: some define QoL as a component of sustainable urbanization, whereas others treat it as a separate construct. This study aims to evaluate and compare both concepts by identifying, weighting, and analyzing their respective indicators, thereby uncovering overlaps, correlations, and distinctions. In particular, it assesses the significance of each indicator within the three dimensions of sustainable urban design: environmental, social, and economic. A mixed-methods approach was employed, beginning with an in-depth literature review and comparative analysis of leading global studies, ranked cities, and official rating systems developed primarily in developed countries. Subsequently, a multi-criteria decision-making (MCDM) method was applied to quantify the importance of each indicator and evaluate their alignment with the three dimensions of sustainability. The results reveal that sustainable urban design comprises 31 indicators, while QoL includes 27, with 19 indicators shared between the two concepts. All identified indicators are distributed across the three core dimensions of sustainability. Specifically, the environmental dimension encompasses 15 indicators for sustainable urban design, accounting for 57.7% of total significance, whereas QoL comprises 10 indicators in this category, contributing 35.67%. In the social dimension, sustainable urban design incorporates 14 indicators (34.82%), while QoL places even greater emphasis here with 15 indicators, representing 54.42%. The economic dimension includes 2 indicators for each concept, contributing 7.43% in sustainable urban design and 9.92% in QoL. These findings underscore that QoL serves as a critical component in the assessment and design of sustainable urban spaces, not only influencing other indicators but also reinforcing aspects—particularly in the social dimension—that are often underrepresented in existing sustainability frameworks. Additionally, the advancement of urban sustainability plays a pivotal role in achieving and enhancing QoL, suggesting a mutually reinforcing relationship between the two constructs.

1. Introduction

Over the past two decades, urbanization has accelerated rapidly, resulting in over half of the global population now residing in urban areas. In some nations, this proportion reaches as high as 80% [1,2]. Projections indicate that by 2030, the global urban population is expected to constitute 60–70% of the total world population [3,4,5]. Since the dawn of the 21st century, the global urban population has experienced a sustained and substantial increase [2]. An analysis of data from the United Nations’ Department of Economic and Social Affairs reveals that approximately 1.5 million people are added to the world’s urban population each week [6]. Regrettably, natural ecosystems are rapidly being replaced by urban developments across the globe, which are responsible for more than 70% of energy-related greenhouse gas (GHG) emissions worldwide [2,3]. All of these problems have a substantial influence on the Quality of Life (QoL) of urban populations. Consequently, governments and experts are encountering mounting difficulties in providing a good QoL in urban areas [7]. The quality of the places where we live heavily influences QoL [8,9], and numerous studies have examined the components of urban areas [10,11,12].

Urban spaces are complex ecosystems that are affected by social, economic, and environmental factors [3]. Sustainable development is an essential concept for improving these factors [13,14]. Sustainable development became popular in 1987 and was defined by the Brundtland Commission report as “development which meets the needs of the present without endangering the ability of future generations to meet their own needs.” It emphasizes the three pillars of sustainability, namely, environmental, economic, and social [1,13,15,16,17]. According to [7], sustainability is conceptualized as the dual challenge of addressing problems that occur within cities as well as those generated by urban systems themselves. Sustainable urbanization is founded upon three interconnected pillars: economic, environmental, and socio-cultural. Each pillar represents a distinct system with its own driving principles [16,18]. The economic pillar aims to enhance human welfare by increasing the production and consumption of goods and services. The environmental pillar focuses on safeguarding the integrity of ecological systems and natural resources. The socio-cultural pillar is centered on enriching the human dimension by fostering harmonious social relations and promoting cultural diversity. This tripartite framework gained global prominence when the United Nations member states adopted the 2030 Agenda for Sustainable Development in September 2015, making sustainability a central global objective. This includes the 17 Sustainable Development Goals (SDGs) and 169 targets and 232 quantifiable indicators, as an important step towards a better, sustainable world and providing QoL for humanity [19]. Among the 17 goals outlined in the post-2015 Sustainable Development Agenda, one emphasizes the need to ensure that cities and human settlements are inclusive, safe, resilient, and sustainable [6].

The concept of QoL is increasingly recognized as converging with sustainability, particularly when examining economic, environmental, and social dimensions. This intrinsic link, coupled with high-quality design, is fundamental to achieving sustainable urbanization [8,20,21]. The United Nations Agenda 21 Report, published in 1993, underscored the critical need to bolster the scientific foundation for sustainable management. It advocated for nations to develop, apply, and institutionalize the necessary tools to enhance QoL encompassing; health, education, social welfare, environmental quality, and economic vitality through sustainable urban development [22]. In recent decades, the intertwined concepts of sustainable urbanization and QoL have garnered significant attention from researchers, diverse academic disciplines, policymakers, architects and urban planners. This interest spans all scales of governance, from local villages and cities to state, national, and international bodies [23,24]. While numerous studies have individually and jointly explored sustainable urbanization and QoL [2,5,6,7,12,13,16,25,26,27,28,29,30,31,32,33], and many international organizations and countries are actively pursuing these goals [34,35,36,37,38,39], there remains a notable gap in the literature. Specifically, a few studies have systematically investigated the precise relationship between their respective indicators within urban environments. Consequently, a comprehensive study comparing and specifying the common indicators of sustainable urbanization and QoL in urban spaces to elucidate their interdependencies and potential areas of convergence or divergence is lacking. This deficiency hinders a clear interpretation and understanding of sustainability and QoL within urbanization, leading to difficulties in their conceptualization and practical application.

This study aims to explore the interrelationship between sustainability and QoL in urban design through a comprehensive analysis of indicators for sustainable urban design and urban QoL. It will systematically investigate the conceptual frameworks of both sustainability and urban QoL, identifying and evaluating the specific indicators associated with each. The research will then compare these indicators to determine their overlap and divergence. A key focus will be to evaluate their importance and correlation based on the three dimensions of sustainability: environmental, social, and economic. Accordingly, this study seeks to explore the following core research questions: What are the commonalities and distinctions between sustainable urban design and urban QoL? What are the key indicators for sustainable urban design and urban QoL as identified in academic literature, international reports, and urban ranking systems? How do the indicators for sustainable urban design and urban QoL overlap and correlate with each other? How does the importance of these indicators vary across the three dimensions of sustainability (environmental, social, and economic) when evaluated from both sustainability and QoL perspectives? These objectives and research questions will be accomplished through a systematic review of relevant academic literature and established urban ranking systems. This will be followed by an analysis of the interrelationships among the identified indicators using comparative methods and multi-criteria decision-making (MCDM) techniques. The findings will contribute to defining a comprehensive set of indicators for both concepts and provide deeper insights into their interconnections and mutual contributions. Such understanding is essential for developing more effective and integrated urban planning strategies.

2. Methodology

This study employed a multi-phased methodology to comprehensively evaluate the interrelationship between sustainable urban design and quality of life (QoL), focusing on key indicators and their significance. The initial phase involved developing a conceptual framework through a comprehensive literature review, focusing on existing research related to sustainable urban design and QoL in urbanization. Studies from highly ranked journals indexed in databases such as Web of Science and Scopus were meticulously analyzed. Concurrently, various international organizations and institutions that rank and analyze cities globally based on sustainability and QoL were investigated. Their specific indicators and ranking methodologies were critically evaluated. From this extensive review, key indicators considered for sustainable urban design and QoL were identified and thoroughly characterized. This characterization involved defining each indicator and understanding its relevance within the respective concepts. This dual-focused approach yielded clear and practical knowledge regarding the indicators pertinent to both concepts. Subsequently, the study determined the correlation between these two sets of indicators. This specific contribution is particularly valuable as it facilitates the development of a holistic design model that integrates both sustainable urbanization and high-quality urban living, making it potentially applicable on a global scale.

Moreover, the Stepwise Weight Assessment Ratio Analysis (SWARA), a Multi-Criteria Decision-Making (MCDM) method, was applied in combination with mathematical and statistical procedures to evaluate the interrelationships and relative importance of the identified indicators in shaping sustainable and high-quality urban environments. The SWARA method allowed for the comparative assessment of indicator significance, highlighting the focus of each concept (sustainable urban design and QoL) within the dimensions of sustainable development. Furthermore, it facilitated the determination of the correlation and interplay between these indicators based on their relative importance and attention.

Multi Criteria Decision-Making (MCDM)

Multi-criteria decision-making (MCDM) methods are powerful and adaptable tools for navigating complex choices, particularly in the selection of sustainability indicators. Since the 1970s, multi-criteria decision-making (MCDM) has been established as a core methodological framework for systematically addressing complex problems involving multiple, and often conflicting, criteria, with extensive application in sustainability assessment [40]. The last decade, in particular, has seen a rapid increase in the development of decision models rooted in MCDM theory [41,42,43]. Among the many MCDM methods available globally, the Stepwise Weight Assessment Ratio Analysis (SWARA) method, introduced in 2010, stands out for its ability to determine the importance of criteria through expert opinion [44,45]. This approach provides valuable guidance for selecting appropriate methods, allowing architects and policymakers to systematically assess and refine sustainability and quality-of-life indicators in accordance with their specific objectives. SWARA has demonstrated its adaptability and efficiency across various problem scales, including engineering, urban planning and architectural design [46,47,48,49]. The SWARA method offers several key advantages:

▪

Low computational and mathematical complexity: It is relatively easy to implement and understand.

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High scalability: It can effectively handle a large number of criteria.

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Suitability for high-level decision-making: It is well-suited for strategic choices.

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Efficient analysis of multiple indicators: It requires minimal pairwise comparisons, streamlining the process.

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Ease of expert opinion elicitation: It simplifies the process of gathering insights from experts.

These benefits are consistent with previous research [41,43]. Given its strengths in coordinating and synthesizing expert judgments, SWARA is particularly well-suited for collecting and assessing indicator data. This enables decision-makers and policymakers to effectively prioritize based on their specific contexts, providing a robust framework for organizing, evaluating, and weighting data to support informed decisions. Building upon the SWARA method, as initially conceptualized by [44], this study determined the relative weights of indicators through the refined and simplified approach presented in [43]. The steps are as follows:

Step 1: Ranking Criteria by Significance.

The initial step requires experts to arrange the indicators (criteria) in descending order of their perceived significance.

Step 2: Assessing Comparative Importance.

This step involves assigning a comparative importance (s_j) to the average value of each criterion. Beginning with the criterion ranked second, you need to evaluate the significance of each criterion (c_j) relative to the criterion immediately following it (c_j+1).

Step 3: Coefficient Calculation

The coefficient (k_j) for each indicator is computed using the following formula:

$${\mathrm{k}}_{\mathrm{j}}=\left\{\begin{array}{c}\begin{array}{cc}1& \mathrm{j}=1\end{array}\\ \begin{array}{cc}{\mathrm{s}}_{\mathrm{j}+1}& \mathrm{j}>1\end{array}\end{array}\right.$$

(1)

Step 4: Recalibrated Weight Determination

The recalibrated weight (q_j) is then calculated using the recursive formula:

$${\mathrm{q}}_{\mathrm{j}}=\left\{\begin{array}{c}\begin{array}{cc}1& \mathrm{j}=1\end{array}\\ \begin{array}{cc}{\displaystyle \frac{{\mathrm{q}}_{\mathrm{j}-1}}{{\mathrm{k}}_{\mathrm{j}}}}& \mathrm{j}>1\end{array}\end{array}\right.$$

(2)

Step 5: Final Weight Normalization

Finally, the normalized weight (w_j) for each indicator is determined, ensuring that the sum of all weights equals one. This is achieved using the formula:

$${\mathrm{w}}_{\mathrm{j}}={\displaystyle \frac{{\mathrm{q}}_{\mathrm{j}}}{\sum _{\mathrm{k}=1}^{\mathrm{m}}{\mathrm{q}}_{\mathrm{k}}}}$$

(3)

The resulting w_j values represent the relative weights of the indicators, quantitatively reflecting their importance based on a comprehensive evaluation of global literature and expert opinion.

In this study, the initial ranking of each criterion was determined using a combination of data from academic literature and expert opinion. Subsequently, mathematical calculations were performed using the refined and simplified SWARA approach, as detailed in Equations (1) and (2). Finally, the normalized weights were calculated using Equation (3). These normalized weights highlight the significance of each indicator based on their comparative analysis and the results from the SWARA method. Furthermore, the accuracy of the mathematical approach was verified by checking that the sum of all weights equaled one (or 100%), which confirmed the validity of the process. This research meticulously applied the SWARA method, ensuring a robust and transparent process for indicator evaluation. In order to guarantee the reliability and validity of the SWARA pairwise comparisons, which were initially derived from a literature review and analysis of ranked city indicators, a panel of university scholars holding PhD degrees and specialized expertise in the field was consulted. For this purpose, a semi-structured interview approach was selected as the primary data collection method. Eligible experts were identified and invited to participate, of whom 15 accepted the invitation and took part in the interviews. This sample size is considered adequate, as the literature suggests that semi-structured interviews can be effectively conducted with as few as three participants and up to approximately 30 participants [50]. The results from each expert were then compiled and used for the SWARA. To further ensure a consensus among the experts regarding the pairwise comparison of indicators for both concepts, the initial results were shared and discussed with the experts. This process helped validate the SWARA results and enhanced the scientific rigor of the study by achieving a consensus on the scaling of the pairwise comparisons. Once expert consensus was reached, the final SWARA was performed. This methodical approach ensured that the pairwise comparisons of indicators were well-structured and unambiguous, significantly minimizing the potential for uncertainties or ambiguities in the data. The rigorous validation process further confirmed the validity and transparency of the study’s findings.

3. Conceptual Framework

3.1. Sustainable Urban Design

In broad terms, sustainable development encompasses all aspects of human life, meeting the basic needs of everyone and providing opportunities for a better life [20]. Sustainable development, when applied to urbanization, is a deliberate strategy. It seeks to tackle challenges arising from social and economic growth, alongside environmental issues at all scales—global, regional, and local. This approach explicitly accounts for the consequences of population growth and urban expansion, aiming to establish a balanced integration of economic development, ecological conservation, environmental protection, and social advancement [3]. Sustainable urbanization is commonly assessed across three interrelated dimensions environmental, social, and economic sustainability each encompassing distinct goals and objectives [18].

Urban sustainability has multiple scopes, the first being environmental sustainability which strives to optimize land use by conserving energy and preserving natural terrain, reducing pollution, establishing parks and green spaces, and maximizing land use efficiency through multi-dimensional and complex development. In other words, the main objective is to ensure that the urban environment is ecologically sustainable and not harmful to the natural world. The second scope of urban sustainability is social sustainability, which is focused on preserving historic buildings and cultural landmarks, as well as maintaining local traditions and values. This scope also aims to revive local communities and promote cultural and local identity, accessibility, safety, and the equitable distribution of space. Essentially, the goal is to ensure that the urban environment is socially sustainable and promotes community engagement and inclusion. The third scope of urban sustainability is economic sustainability, which emphasizes economic growth, reducing development costs, bridging the gap between social classes by ensuring access to urban infrastructure and amenities, and improving overall quality of life (QoL). To achieve this, it is necessary to maintain balanced relationships between various economic factors, ensure efficient growth and development, and increase productivity.

Urban sustainability refers to the concept of creating and managing cities and urban spaces in a way that considers their social, economic, and environmental impacts. The goal is to create resilient environments that sustain the well-being of current populations while safeguarding the capacity of future generations to achieve an equivalent or enhanced QoL [51]. In essence, sustainable urban spaces are designed to promote high degrees of health and well-being, economic security, and the integrity of the ecosystem on which all life and production depend [24]. Notably, urban areas cover less than 2% of the Earth’s land surface yet consume approximately 75% of its natural resources [15]. This highlights the urgency of the need for sustainable urban development. In the latter half of the 20th century, the issues of natural resource scarcity, environmental pollution, and population growth became the main worldwide concerns, prompting the appearance of the concept of sustainable development in the 1970s. This concept has influenced the approach to the theory and practice of urban management [1]. Global urbanization, accelerating rapidly in recent years, has created significant environmental and social challenges. In response, the United Nations has established the 2030 Agenda for Sustainable Development, which includes 17 Sustainable Development Goals (SDGs). One of these, SDG 11, is specifically dedicated to making cities and human settlements inclusive, safe, resilient, and sustainable [2,52]. This focus is depicted in Figure 1.

Overall, the concept of urban sustainability is critical for ensuring the long-term viability of urban areas. By prioritizing social, economic, and environmental factors, urban sustainability can promote a better QoL for everyone who lives and works in urban spaces. This can be achieved through careful planning and management, which takes into account the impacts of urbanization on the environment, society, and economy. A definition by the the United Nations states that sustainable urban spaces are spaces where achievements in social, economic, and physical development are made to last [22]. According to a review of sustainable community frameworks, the definition typically incorporates seven core components: governance, transport and connectivity, services, environment, economy, housing and the built environment, and sociology and culture [54]. The successful implementation of these frameworks is heavily reliant on effective and good design, which is a key element for home and community agencies aiming to create sustainable residential environments [55].

The primary objective of human settlement planning is to enhance the social, economic, and environmental quality of settlements, thereby improving the living and working conditions for all individuals [20]. Urban design is defined as the art of creating spaces for people, encompassing a process that addresses both the functional requirements and aesthetic aspirations of inhabitants [17]. The urban spaces, as an essential ingredient of urban sustainability, have adapted to people’s changing behavior; hence, urban planning or design needs a renewed observation. Across the globe, new public spaces are being developed, while traditional public space typologies are being adapted and retrofitted to meet contemporary social, functional, and cultural demands. Also, it has been accepted that urban spaces have a vital role in urban sustainability and residents’ life quality [56]. Effective urban design is crucial for creating places that are sustainable across social, environmental, and economic dimensions. As a form of sustainable design, good urban design does not merely focus on the visual appearance of spaces but prioritizes enhancing their functionality and overall performance [8]. Sustainable urbanization is a strategic approach to designing urban environments that are not only desirable for current residents but are also resilient for future generations [18]. This process is executed through sustainable urban design, a methodical process that integrates specific principles and practices into urban development projects. These principles encompass creating pedestrian-centric spaces, fostering urban connectivity, and promoting diverse land uses and housing materials. Furthermore, sustainable urban design emphasizes high architectural quality, increased urban density, and the implementation of intelligent transportation systems. A crucial element is the life-cycle management of resources, including energy, water, and materials, as well as waste. The ultimate goal is to enhance the overall QoL for residents by ensuring both a comfortable interior and exterior environment within these urban spaces [16]. To accurately measure the effectiveness of these practices, a range of indicators must be incorporated into the design and assessment of all urban projects [57].

Indicators for Sustainable Urban Design

Sustainability indicators are a statistical tool used to measure various aspects of sustainable development in a way that is easy to understand and communicate, as stated in [16]. Sustainable indicators can be applied at different levels, ranging from housing to neighborhood, city, province, country, and even globally. A variety of sustainable indicators have been developed for achieving sustainability in urban areas, created by various organizations for different purposes [58]. For example, the Sustainable Cities Index (SCI) is a comprehensive measure of sustainability that evaluates the social, environmental, and economic health of cities, providing insight into urban sustainability from the citizens’ perspective. The SCI ranks 100 global cities based on the three pillars of sustainability: People (social), Planet (environmental), and Profit (economic), as described in [51]. The three pillars are interconnected with the United Nations’ Sustainable Development Goals (SDGs) and are used to monitor progress towards fulfilling SDGs commitments. These goals include various areas, such as health and well-being, water and sanitation, industry, innovation and infrastructure, creating inclusive, safe, resilient, and sustainable cities, mitigating climate change impacts, supporting life on land, and forming partnerships. A ranking of the top ten sustainable cities in 2024 has been provided in

Table 1. The top 10 most sustainable cities, ranked by social, environmental, and economic performance, were identified in the Arcadis Sustainable Cities Index report [59].

Rank	City	Country	Key Sustainability Performance
1	Amsterdam	Netherlands	Ranks highest on the index, driven by robust economic performance, social equity, and substantial investments in renewable energy. Demonstrates excellence in income levels, quality of life, employment rates, and transportation infrastructure.
2	Rotterdam	Netherlands	High scores in environmental sustainability, particularly in waste management and renewable energy initiatives. Known for its innovative water management systems.
3	Copenhagen	Denmark	Extensive cycling infrastructure and commitment to carbon neutrality by 2025. High performance in sustainable transport and green spaces.
4	Frankfurt	Germany	Excels in green finance and sustainable transport systems. Strong in water sanitation and waste management.
5	Munich	Germany	Demonstrates robust performance in water sanitation, waste management, and minimizing greenhouse gas emissions, alongside strong outcomes in economic stability and social equity
6	Oslo	Norway	Sets the benchmark for electric vehicle infrastructure. High scores in renewable energy usage and low-emission transport.
7	Hamburg	Germany	High performance in sustainable energy systems and low-emission transport. Strong in economic performance and social equity.
8	Berlin	Germany	Focuses on green building initiatives and renewable energy projects. High scores in social equity and economic stability.
9	Warsaw	Poland	Notable progress in renewable energy production and socio-economic factors, such as female labor force participation. Strong in economic performance and social equity.
10	London	UK	Strong in economic performance and social equity, with ongoing efforts to improve air quality and reduce carbon emissions. High scores in sustainable transport and green spaces.

, where Amsterdam and London have been placed as the first and tenth cities, respectively.

Various organizations have defined their own set of indicators for sustainable urbanization based on their respective goals and objectives. The United Nations (UN) considers indicators to be simplified models that facilitate the understanding of complex topics and promote sustainability across various fields, with a particular focus on urbanization [36]. The Organization for Economic Co-operation and Development (OECD) [35], an international organization committed to building better policies for better lives, aims to promote prosperity, equality, opportunity, and well-being for all countries, including its own member states. Meanwhile, the European Commission, a multi-disciplinary organization, defines indicators for sustainable development in various aspects, according to its role in setting priorities and implementing policies throughout the European Union [34]. These organizations have made significant efforts to promote sustainable urbanization, and their mission is now widely recognized across various disciplines. Several studies and organizations have focused on sustainable urban design and its indicators, which are summarized in

Table 2. Identification of sustainable urban design indicators across various studies and rating systems.

Dimensions	Indicators	Related Studies										Rating Systems
		[31]	[12]	[2]	[32]	[13]	[7]	[16]	[5]	[60]	[61]	LEED	BREEAM	CASBEE	SBTool PT-UP	GSAS/QSAS
Environmental	Energy	✓		✓	✓	✓		✓	✓	✓	✓		✓		✓	✓
	Water	✓		✓	✓	✓	✓	✓	✓	✓	✓				✓	✓
	Transportation & Mobility	✓	✓	✓	✓	✓	✓	✓		✓	✓		✓		✓
	Management	✓	✓	✓	✓	✓	✓	✓	✓	✓	✓			✓	✓	✓
	Air quality		✓	✓	✓	✓	✓	✓	✓	✓	✓			✓		✓
	Housing	✓	✓		✓	✓	✓	✓	✓	✓	✓	✓
	Material & Resources	✓	✓	✓	✓	✓		✓			✓		✓		✓	✓
	Land use	✓	✓	✓	✓		✓			✓	✓	✓	✓	✓	✓	✓
	Ecology	✓	✓		✓	✓		✓			✓		✓	✓	✓
	Landscape & Greenery	✓	✓	✓	✓		✓	✓				✓
	Biodiversity	✓	✓			✓	✓	✓	✓						✓
	Infrastructure	✓				✓		✓	✓		✓			✓	✓
	Pedestrian & Bicycle	✓	✓	✓					✓
	Natural hazards					✓	✓				✓
	Density		✓		✓
Social	Regional priority											✓
	Culture	✓	✓			✓	✓		✓	✓	✓			✓	✓	✓
	Design principles	✓	✓			✓				✓	✓	✓		✓	✓
	Community engagement	✓		✓			✓			✓		✓				✓
	Policy & Governance	✓				✓	✓	✓		✓	✓		✓
	Telecommunications	✓
	Satisfaction	✓	✓		✓				✓		✓
	Diversity		✓		✓			✓
	Accessibility		✓	✓	✓	✓	✓							✓
	Health & Well-being	✓		✓	✓	✓	✓	✓	✓	✓			✓		✓
	Safety & security					✓	✓		✓		✓				✓
	Innovation					✓			✓	✓	✓	✓
	Education					✓	✓	✓	✓
	Equality						✓	✓
Economic	Business & Economy	✓	✓	✓		✓	✓	✓	✓	✓	✓		✓			✓
	Employment	✓			✓				✓	✓	✓				✓

.

Sustainable urbanization is an essential approach to human life that requires careful consideration of indicators and criteria in the design and assessment of sustainable urban spaces. Many studies have been conducted by researchers and organizations, each defining sustainable urbanization based on their own aims and strategies. Numerous indicators and criteria have been proposed for sustainable urban spaces. Upon review of these studies and organizational works, it is evident that sustainable urbanization, as part of sustainable development, comprises three dimensions of sustainability: environmental, economic, and social. These dimensions encompass a significant number of indicators. Generally, the majority of indicators defined in various studies share the common aim of enhancing sustainability and QoL.

3.2. Quality of Life (QoL)

The concept of quality of life (QoL) is inherently complex and multidimensional, often overlapping with related constructs such as well-being, satisfaction, and happiness, which can make precise differentiation challenging [24]. Despite the attention it has received in numerous studies, there is no universally accepted definition of QoL [29,30]. Dalkey and Rourke offer a broad definition, describing it as “a person’s sense of well-being, satisfaction, or happiness.” [33]. However, QoL can also be understood subjectively, reflecting an individual’s personal assessment of their life circumstances [33]. For instance, Emerson characterizes QoL as the fulfillment of a person’s values, goals, and needs through the realization of their abilities and chosen lifestyle [62].

Although QoL is a contemporary concept that has attracted significant scholarly attention, its roots can be traced to classical philosophers such as Aristotle (384–322 BC), who explored the notion of ‘the good life’ and the role of public policy in promoting human well-being [28]. Moreover, QoL encompasses many dimensions, such as family, work, finances, age, and health. It also involves the relationship between inhabitants and their urban environment [63,64]. In general, the assessment of QoL can be made in two ways: subjective and objective. The subjective assessment is based on psychological responses such as life satisfaction, job satisfaction, and personal happiness, while the objective assessment refers to external life conditions, such as the physical environment, economic factors, and technical factors [22,26,29,30,33,65,66]. Most experts now agree that both objective and subjective indicators should be combined to provide a better understanding of QoL, and well-being and happiness are often used interchangeably [62]. The quality of public spaces or living environment is a key factor in influencing people’s overall QoL, and urban sustainable development plays a vital role in this regard [67]. In fact, the Sustainable Development Agenda 2030 highlights the significance of urban sustainable development for QoL [1,55]. Sustainable urban design has a vital role in ensuring a high quality of life, and it is essential to consider economic, social, and environmental conditions in achieving sustainable development [8,28]. Beyond sustainable development, a substantial body of indicators has been established to characterize QoL within urban environments.

Indicators for QoL in Urban Space

The term “quality of life in urbanization” is not easy to define as it involves complex and interrelated factors, and different experts may have different definitions. Essentially, it refers to the interactions and connections among physical features [28]. Quality of life can be conceptualized across multiple domains, including: physical well-being (e.g., health, occupational conditions, and nutrition); material conditions (e.g., economic status, housing, and overall welfare); psychological well-being (e.g., emotions, attitudes, values, self-esteem, job satisfaction, stress, and the moral-psychological climate within groups); education and personal development (e.g., learning opportunities, educational quality, skill acquisition, and practical application of knowledge); social relationships (e.g., connections with family, peers, and the wider community, as well as social support); opportunities for self-expression and leisure (e.g., recreation, hobbies, creative activities, and entertainment); and safety and environmental quality (e.g., personal security, workplace conditions, and broader economic, political, and legal contexts) [25]. The ten global cities identified in

Table 3. The top 10 cities with the highest QoL, as identified in the report by a reputable organization that is referenced in sources [68,69,70,71].

Rank	City	Country	Quality of Life Performance
1	Vienna	Austria	Excellent infrastructure, extensive public transport, first-class healthcare, high education. Known for its cultural heritage, green spaces, and low crime rates.
2	Zurich	Switzerland	High political stability, excellent healthcare, strong economy, clean environment. Offers a high standard of living with a mix of urban and natural attractions.
3	Auckland	New Zealand	High environmental quality, good public transport, strong community networks. Known for its beautiful landscapes, outdoor activities, and friendly locals.
4	Copenhagen	Denmark	High employment rates, excellent education, strong social connections, clean environment. Famous for its bike-friendly streets, green spaces, and high levels of civic engagement.
5	Geneva	Switzerland	High income levels, excellent healthcare, strong education system, high life expectancy. Known for its international organizations, beautiful lakeside setting, and safety.
6	Frankfurt	Germany	Strong economy, good healthcare, high safety, excellent public transport. A major financial hub with a blend of modern and historical architecture.
7	Munich	Germany	High job security, excellent public transport, high air quality, strong economy. Known for its cultural scene, green spaces, and high standard of living
8	Vancouver	Canada	High environmental quality, good healthcare, strong community networks. Offers a mix of urban living and natural beauty, with a focus on sustainability.
9	Sydney	Australia	High life expectancy, excellent healthcare, strong education system, good public transport. Known for its iconic landmarks, vibrant cultural scene, and outdoor lifestyle.
10	Dusseldorf	Germany	High safety, good healthcare, strong economy, excellent public transport. Known for its fashion industry, cultural events, and high quality of life.

, consistently ranked highest for quality of life, were determined through a comprehensive analysis of reports from various international organizations.

Numerous organizations are dedicated to the enhancement of urban QoL, offering a range of metrics for its design and enhancement. A notable example is Mercer, a leading data provider that assesses QoL through a comprehensive set of indicators. These indicators include: Consumer goods availability, economic conditions, housing quality, healthcare and medical services, the natural environment, political and social contexts, public infrastructure and transportation, recreational facilities, educational institutions, and the broader socio-cultural environment. [37]. Moreover, Numbeo is a well-known global organization that provides information and comparisons on various aspects of QoL. These aspects include the cost of living and purchasing power, housing affordability, and levels of air and water pollution, among others. Numbeo also provides data on crime rates, the quality of the healthcare system, and traffic-related concerns such as commute times [38]. By gathering and presenting such information, Numbeo enables individuals and organizations to make more informed decisions about where to live and work, and to assess the potential QoL in various locations around the world. Similarly, the Organization for Economic Co-operation and Development (OECD) has created the Better Life Index to provide a comprehensive tool for assessing QoL. This index allows users to visualize and compare key factors that contribute to QoL across countries. These factors include education, housing, the environment, health, and overall satisfaction, among others [39]. By presenting such information in a clear and user-friendly manner, the Better Life Index empowers individuals and policymakers to make more informed decisions and to work towards improving QoL in their respective communities. Numerous studies conducted by researchers and organizations have investigated QoL issues within urbanized environments. A summary of selected findings from these investigations is presented in

Table 4. Identification of QoL indicators in urban spaces across various studies and organizations.

Dimensions	Indicators	Related Studies										Organizations and Institutions
		[33]	[25]	[26]	[27]	[6]	[28]	[29]	[30]	[72]	[73]	Mercer	Numbeo	WCCD	OECD	UN-Habitat
Environmental	Air quality	✓		✓	✓	✓	✓	✓	✓	✓	✓	✓	✓	✓	✓	✓
	Transportation & Mobility	✓					✓		✓	✓	✓	✓	✓	✓		✓
	Landscape & Greenery	✓	✓	✓								✓
	Housing			✓					✓		✓	✓	✓	✓	✓	✓
	Material & Resources	✓	✓
	Infrastructure							✓			✓			✓
	Water							✓					✓	✓
	Land use			✓										✓
	Natural hazards			✓
	Management									✓				✓
Social	Culture	✓	✓	✓		✓	✓		✓	✓	✓	✓		✓		✓
	Health & Well-being	✓		✓		✓			✓	✓	✓	✓	✓	✓	✓	✓
	Physical state		✓		✓		✓	✓		✓
	Safety & Security		✓	✓				✓	✓		✓		✓	✓	✓	✓
	Education	✓							✓	✓	✓	✓		✓	✓	✓
	Policy & Governance				✓	✓	✓			✓		✓		✓		✓
	Psychology & Happiness	✓	✓				✓			✓		✓		✓
	Satisfaction	✓						✓							✓	✓
	Self- expression		✓		✓											✓
	Community engagement				✓						✓	✓			✓	✓
	Facility & Services			✓	✓							✓		✓		✓
	Youthfulness	✓												✓
	Activities	✓
	Accessibility			✓										✓		✓
	Flexibility			✓
Economic	Business & Economy				✓	✓	✓	✓	✓	✓	✓		✓	✓	✓	✓
	Employment								✓		✓				✓

.

Consequently, QoL is understood as a comprehensive measure, influenced by several critical environmental, social, and economic dimensions. These dimensions are commonly quantified through various indicators, as outlined in Table 4. While the specific indicators utilized in diverse studies may exhibit variation, their consistent fundamental aim is to enhance the QoL of an individual or a group.

4. Results

The early 21st century marked a significant turning point in urban development, driven by escalating environmental concerns and a heightened focus on Quality of Life (QoL). This period saw the emergence of sustainable and high-quality urban spaces as a dominant paradigm in urban planning and design. Consequently, a diverse array of design approaches, standards, evaluation methods, and tools has been developed globally to simultaneously improve both sustainability and the QoL in urban environments at various scales. Each of these innovative frameworks provides a unique set of design indicators that act as benchmarks for achieving sustainable and high-quality urban objectives. These indicators have become indispensable resources for architects, urban planners, and policymakers, guiding their efforts to integrate principles of sustainability and QoL into their projects. Nevertheless, the rapid proliferation and considerable similarity among these indicators have introduced challenges in their consistent interpretation and precise definition within the field.

This study evaluated the most relevant studies, along with highly ranked cities globally, based on their sustainability and quality of life. The aim was to identify specific indicators and the correlation between sustainable urban spaces and the QoL in urban areas. Additionally, organizations and institutions that analyze and rank cities worldwide for sustainability or QoL were also assessed based on their considered indicators. Our analysis revealed 31 indicators considered in the design and evaluation of sustainable urban spaces, as detailed in Table 2. Furthermore, 27 indicators were identified as crucial for the design and evaluation of urban spaces with a high quality of life, presented in Table 4. For a detailed analysis of each concept and the importance of its indicators, an approach focusing on sustainable development dimensions and Multi-Criteria Decision-Making (MCDM) analysis was employed. This approach allowed for an in-depth examination of the indicators, emphasizing their contribution to the evaluation and determination of the correlation between sustainable urban design and QoL in urban spaces.

Therefore, within the realm of MCDM methods, Stepwise Weight Assessment Ratio Analysis (SWARA) was comparatively employed to assess both sustainability and QoL indicators. This comparative approach, facilitated by SWARA results, allowed for a comprehensive assessment of indicators and their interrelationships, along with their importance in achieving sustainable urban spaces and a high quality of life. This understanding will assist architects and policymakers in appropriately characterizing indicators based on local conditions. The importance and correlation of indicators for the environmental dimensions of sustainability and QoL in urban spaces are further described in Figure 2.

The comparison of indicators for sustainable urban design and QoL in urban spaces revealed a significant overlap. Sustainable urban design practices encompassed 15 environmental indicators, all of which were also considered within the 10 QoL indicators. This substantial overlap suggests a strong correlation between QoL and sustainable urban design, particularly concerning environmental issues. Furthermore, the importance of each indicator, as determined by the SWARA method, for both the environmental dimension of sustainable urban design and QoL is presented in Figure 2. For sustainable urban design, Management emerged as the most important indicator (5.67%), while Density was the least important (1.08%). In contrast, within the QoL indicators, Air quality held the highest importance (9.14%), and Natural hazards had the lowest (1.17%). Despite the individual indicator rankings, the greater number of indicators considered within sustainable urban design, coupled with its broader scope in urban planning, indicated a higher overall importance and consideration compared to QoL.

A comparative analysis of the social dimension indicators for sustainable urban design and QoL reveals both shared and unique aspects. Sustainable urban design encompasses 14 indicators, while QoL includes 15 indicators. Of these, 7 indicators overlap between the two concepts, demonstrating their inherent correlation and interrelationship. The remaining indicators are distinct and specific to each concept, highlighting their particular focus. In the context of sustainable urban design, the relative importance of indicators varied significantly. “Health & Well-being” emerged as the most crucial indicator, accounting for 4.41% of the total importance. Conversely, “Telecommunication” was identified as the least important, contributing only 0.74%. Similarly, within the QoL framework, “Health & Well-being” consistently demonstrated the highest importance, representing 7.39% of the total. In contrast, “Accessibility” was determined to have the lowest importance at 1.06%. This shared emphasis on “Health & Well-being” further underscores the strong correlation between sustainable urban design and quality of life. Despite the overlap, the total importance and consideration of QoL indicators in the social dimension of urban design were found to be higher than those for sustainable urban design in urban spaces. This can be attributed to the larger number of indicators specifically considered under the QoL framework within the context of urban design. Detailed results are presented in Figure 3.

The economic dimension of both sustainable urban design and QoL encompasses two common indicators, highlighting a significant correlation between these two concepts. Specifically, Business & Economy is a shared indicator, representing 4.64% in sustainable urban design and a more substantial 7.51% in QoL. Similarly, Employment is another common indicator, accounting for 2.79% in sustainable urban design and 2.41% in QoL. The higher weighting of the economic dimension within the QoL framework suggests that, from an economic perspective, QoL holds a more prominent position in urban design considerations compared to a purely sustainable urban design approach. These detailed results are visually represented in Figure 4.

5. Discussion

The escalating rates of urbanization and population growth present significant challenges to ecosystem integrity and environmental quality, consequently impacting human well-being. In response, sustainable urbanization has emerged as a critical paradigm for improving the QoL for urban inhabitants. While extensive research explores the relationship between sustainable urbanization and QoL, a universally accepted definition for these multifaceted concepts remains elusive. Existing literature offers diverse perspectives on the primary drivers of QoL within the context of sustainable development.

Several studies emphasize the social dimension as a primary factor influencing QoL [22,74], while others argue for the collective contribution of all three pillars of sustainable development: environmental, social, and economic [75]. Our study, which examines the explicit relationship between sustainable urbanization and QoL through a specific set of indicators, aligns more closely with the latter perspective. Furthermore, some scholars have critically evaluated existing sustainability frameworks, proposing new, more comprehensive theories. For instance, [76] introduces “sustainalism,” a socio-economic-environmental theory with a strong philosophical foundation that emphasizes a good quality of life. Similarly, [77] discusses how sustainability management can strengthen both design and QoL. Moreover, [78] identify the factors that influence QoL and sustainable development in the urban context. However, a significant gap remains in the literature regarding the detailed correlation between sustainability and QoL in urban design. While existing studies recognize the interconnectedness of these two concepts, they often lack a clear, quantifiable, and comprehensive framework for identifying and analyzing indicators of both concepts within a single study. Most research addresses sustainability and QoL separately or focuses primarily on conceptual definitions and multiple criteria, without systematically comparing or evaluating specific indicators that capture the nature and significance of their interrelation. This gap is particularly pronounced due to the absence of a standardized methodology for defining indicators for each concept and, consequently, for assessing their correlations across the three dimensions of sustainability.

To address this gap, the present research undertakes a systematic review of academic literature and organizational frameworks to identify, characterize, and assess the significance of widely recognized indicators of sustainable urbanization and QoL. These identified indicators, which align with the environmental, social, and economic dimensions of sustainable development, offer practical utility for urban planners, designers, and policymakers. By integrating these indicators into urban design and assessment frameworks, the sustainability and overall quality of urban environments can be significantly improved. Furthermore, this research provides a foundational resource for future investigations into sustainable design and QoL indicators, underscoring the critical interplay between these two vital domains.

Through an examination of their respective indicators, the research revealed that out of 31 indicators identified for sustainable urban design and 27 for QoL, a substantial 19 indicators are shared. These shared indicators are comprehensively categorized across the environmental, social, and economic dimensions, aligning with the framework of sustainable urban design. In the environmental dimension, sustainable urban design encompassed 15 significant indicators (57.7% of its total significant indicators), while QoL identified 10 significant indicators (35.67%). Notably, all 10 of the significant environmental QoL indicators overlapped with those of sustainable urban design, underscoring a strong convergence in this domain. For the social dimension, sustainable urban design included 14 significant indicators (34.82%), whereas QoL highlighted 15 significant indicators (54.417%). Here, seven common indicators were identified, suggesting that QoL indicators can serve as a vital complement to sustainable urban design, particularly in addressing social aspects often underrepresented in traditional sustainable design paradigms. The economic dimension exhibited complete overlaps, with both sustainable urban design and QoL identifying the same two indicators, accounting for 7.43% and 9.92% of their respective significant indicators.

In summary, sustainable development represents a cornerstone concept crucial for both elevating human well-being and ensuring responsible resource stewardship. In response to the escalating rates of urbanization and population growth, which increasingly threaten ecological integrity and human quality of life, sustainable urbanization has emerged as a paramount approach for enhancing the QoL of urban residents. While a universally accepted definition for both sustainable urbanization and QoL remains elusive, this study has successfully delineated a set of common, actionable indicators consistent with the tripartite framework of sustainable development. These indicators offer a valuable tool set for improving the sustainability and livability of urban spaces through more informed design principles and rigorous assessment methodologies. The study provides specific insights into sustainable urban design and QoL based on their associated indicators, highlighting each concept’s contribution to urban development. Moreover, it offers a comprehensive understanding of the interrelationships between these two concepts through their shared indicators. This approach illustrates their respective contributions and emphasis on different sustainable development dimensions. The findings underscore that sustainable development serves as a foundational principle, essential for enhancing human well-being while promoting responsible resource management.

However, a key limitation of this study lies in the inherent variability and lack of universally accepted definitions and standardized frameworks for sustainable urban design and urban QoL. Despite employing a systematic literature review and expert consensus to identify and weight relevant indicators, the selection and interpretation of these indicators may be influenced by the subjective perspectives of the consulted experts and the specific sources analyzed. Additionally, the reliance on existing academic literature, international reports, and urban ranking systems may limit the inclusion of emerging or context-specific indicators not yet widely recognized. Consequently, while the study provides a comprehensive and integrative framework, its findings may require further validation across diverse geographic, cultural, and socio-economic contexts to ensure broader generalizability and applicability in urban planning practice.

6. Conclusions

Rapid urbanization and escalating population growth underscore pressing global challenges, including diminished quality of life, environmental degradation, and resource depletion. Consequently, there is an increasing imperative in urban design and assessment to prioritize sustainable urbanization and the quality of life (QoL) within urban environments. While these are broad and extensively researched concepts, their definitions and associated indicators often vary across studies and organizations, reflecting diverse objectives. Generally, indicators for sustainable urbanization encompass the three pillars of sustainability: environmental, social, and economic. In parallel, QoL indicators focus on human well-being and satisfaction, addressing the multifaceted aspects influencing living conditions. Numerous studies have established an inherent and reciprocal link between sustainable urbanization and QoL, with the primary objective of sustainable urban development being the enhancement of urban residents’ QoL.

This study specifically investigated the relationship between sustainable urban design and QoL, identifying significant commonalities. The comparison of sustainable urban design and QoL indicators in urban spaces reveals substantial overlaps and correlations across environmental, social, and economic dimensions. All 15 environmental indicators of sustainable urban design align with 10 QoL indicators, indicating a strong link between environmental sustainability and QoL. In the social dimension, 7 of the 14 sustainable urban design indicators overlap with 15 QoL indicators, reflecting both shared and distinct aspects, with QoL indicators generally given greater emphasis. Economically, two common indicators highlight a significant correlation between the concepts. These findings underscore the interconnectedness of sustainable urban design and QoL, emphasizing their integrated consideration in urban planning.

Consequently, these findings underscore the pivotal role of QoL as an essential indicator in the assessment and design of sustainable urban spaces, acting to influence and enhance other sustainability metrics. The attainment of urban sustainability is shown to significantly contribute to the achievement of a higher QoL. In conclusion, sustainable urbanization and QoL are inextricably linked concepts, both fundamental to fostering livable and resilient urban environments. The identified shared and complementary indicators provide a robust framework, offering a clear roadmap for urban planners and designers to create cities that are not only environmentally sound and economically viable but also socially just and conducive to human well-being.