A Spatial Spectrum Framework for Age-Friendly Environments: Integrating Docility and Life Space Concepts

Abstract

As societies confront rapid demographic aging, developing inclusive and age-friendly environments has become a central challenge in urban and housing research. This study proposes an integrated conceptual framework for Aging in Community, extending the traditional Aging in Place model through a multi-scalar perspective. Grounded in Lawton’s Docility Hypothesis and the Life Space Theory, the framework reinterprets aging not as a linear contraction but as a process of adaptive spatial integration across individual, communal, and urban scales. Drawing on spatial spectrum modeling and illustrative cases from South Korea, the analysis demonstrates how universal design principles and intergenerational living strategies can promote mobility, emotional well-being, and social participation among older adults. The study highlights the dynamic interaction between built environments and functional autonomy, revealing how spatial structure and perceived accessibility jointly sustain participation and independence. By conceptualizing Extended Community Space, the research bridges fragmented models such as AIP, NORC, and AFC into a cohesive continuum and positions Korea as an anticipatory laboratory for high-density aging societies. Ultimately, the AIC framework offers both theoretical and policy-level insights for advancing age-friendly design, guiding planners, architects, and policymakers toward adaptive, inclusive, and sustainable approaches that transform longevity into a foundation for collective well-being and social resilience.

1. Introduction

1.1. Background and Rationale

Environmental psychology, rooted in Lewin’s formulation B = f(P,E), emphasizes that human behavior arises from the dynamic interplay between personal (P) and environmental (E) factors. Building on this foundation, Lawton’s ecological theory of aging explains that the balance between functional competence and environmental press directly determines the life quality and adaptive capacity of older adults. This theoretical basis emphasizes the active interaction between personal ability and spatial support systems. His Docility Hypothesis further suggests that individuals with diminished capacity are particularly sensitive to environmental conditions, underscoring the necessity of age-responsive design. This ecological perspective informed the widely adopted concept of Aging in Place (AIP), which focuses on enabling older adults to remain in familiar homes through housing adaptations. However, the individual dwelling-centered focus of AIP has revealed limitations in addressing broader psychosocial needs such as social participation, community belonging, and environmental continuity. In this context, the transition from AIP to AIC represents not a simple expansion of living scale but a paradigm shift toward interdependence, shared resources, and community resilience.

In response, the concept of Aging in Community (AIC) has emerged as an integrative model that extends beyond the private home, prioritizing autonomy, emotional stability, and interdependence within community-based networks [1]. Parallel to these developments, community gerontology has evolved as a framework that recognizes the importance of local social infrastructures, collective well-being, and civic engagement in shaping age-friendly environments. This perspective expands the focus from individual adaptation to the interplay between personal agency and structural conditions, linking micro-level behaviors with meso- and macro-level policy contexts.

The Life Space Theory, proposed by May, Nayak, and Isaacs [2], advanced our understanding of how the spatial extent of mobility—from rooms to urban environments—affects autonomy and well-being. Empirical studies by Peel et al. [3] and Parker et al. [4] confirmed that the size of one’s life space is a strong predictor of social integration, independence, and overall quality of life. Despite their conceptual compatibility, the Docility Hypothesis and Life Space Theory have typically been applied in isolation—one to residential adaptation, the other to mobility and activity ranges. This separation has constrained theoretical integration and limited the potential for a comprehensive understanding of the spatial spectrum shaping older adults’ everyday lives.

The present study addresses this gap by uniting these perspectives within a single framework, laying the foundation for a more holistic model of age-friendly design. It is positioned as a theoretical and conceptual contribution, integrating fragmented frameworks such as Aging in Place (AIP), Naturally Occurring Retirement Communities (NORC), and the WHO’s Age-Friendly Cities (AFC) into a coherent Aging in Community (AIC) paradigm. Rather than presenting empirical data, this paper focuses on theoretical synthesis and conceptual modeling, providing a foundation for subsequent empirical validation. This approach allows the AIC framework to serve as a bridge between descriptive observations and actionable design strategies for age-friendly environments.

1.2. Research Objectives and Distinctiveness

This study aims to establish a theoretical framework for understanding the environments of older adults in a multidimensional and integrative manner. By integrating the Docility Hypothesis—which conceptualizes environmental sensitivity and adaptive behavior—with the Life Space Theory—which describes the spatial expansion of autonomy and participation—this study develops a theoretically unified framework for Aging in Community (AIC). Unlike prior studies that treated these theories as separate domains, the present research positions them as complementary dimensions of adaptability across scales, from home to community to city. In this regard, the integration proposed here is not merely a conceptual alignment but a theoretically grounded synthesis that constructs an ecological continuum of aging—from micro-level residential adaptation to macro-level community and urban design—offering a multi-scalar basis for age-friendly frameworks. Particular emphasis is placed on how these theoretical pillars operate across different spatial scales—from home modifications to broader community and urban environments—and how they can be extended to encompass intergenerational living and participatory community contexts. In pursuing these objectives, the study seeks to move beyond the dwelling-centered notion of Aging in Place (AIP) and provide theoretical grounding for the more socially and communally oriented concept of Aging in AIC. Through this synthesis, the research contributes to the advancement of environmental gerontology by proposing a unified lens for interpreting spatial experience, autonomy, and environmental vulnerability. It further establishes a conceptual bridge linking personal adaptation with community and policy-level design strategies.

While this study shares its conceptual roots with Wahl and Gerstorf [5], who identified environmental docility and life space as critical resources for aging well, it departs significantly in both scope and orientation. Their work primarily conceptualized these constructs at the psychological and behavioral levels within contextual gerontology. In contrast, the present study extends their theoretical insights into the spatial, environmental, and policy domains. By translating the person–environment interaction into a spatial spectrum framework for age-friendly environments, this research advances a theoretical evolution—from individual adaptation toward collective, community-based environmental design—bridging micro-level conceptualization and macro-level application.

1.3. Research Questions & Methodological Approach

Guided by this theoretical integration, the study addresses the following research questions that connect conceptual understanding with spatial and policy implications:

• How should the design of spatial environments be linked to functional decline in older adults?
• How can the Docility Hypothesis and Life Space Theory be jointly applied across diverse spatial scales?
• From the perspective of AIC, how can a comprehensive and adaptable design framework for age-friendly environments—spanning home, community, and urban spaces—be conceptualized?

To answer these questions, the study adopts a theoretical review and synthesis approach. By applying the interpretive framework of contextual gerontology and analyzing existing case studies, it maps the expansion of the spatial spectrum and proposes a theoretically integrative model that can inform practical applications.

This study is positioned as a theoretical and conceptual work. While it does not employ empirical testing, the inclusion of photographic and spatial illustrations serves not merely as theoretical visualization but as empirical grounding, demonstrating how the proposed framework manifests in real community environments. These real-world cases, drawn from actual housing and neighborhood regeneration projects, substantiate the empirical validity of the theoretical constructs by visualizing their functional, social, and environmental applicability. In doing so, the study bridges theoretical abstraction and practice-based evidence, reinforcing both the credibility and transferability of the proposed framework.

Rather than presenting statistical or experimental evidence, it synthesizes established theories—Docility and Life Space—into a unified framework supported by photographic images and visual documentation from real environments. These visual cases are not merely illustrative supplements but function as interpretive evidence that anchors the theoretical framework in recognizable spatial contexts. Consequently, the study sets the stage for the research framework developed in the next section.

1.4. Definitions of Key Terms

• Environmental Gerontology
  A multidisciplinary field that examines the interactions between older adults and their environments, aiming to enhance quality of life in later life. It integrates physical and social environmental factors with the psychological and functional characteristics of aging [6].
• Docility Hypothesis
  Proposed by Lawton [7], this hypothesis argues that individuals with lower functional competence are more sensitive to environmental conditions. It underscores the importance of environmental adaptation in maintaining autonomy and independence among older adults.
• Life Space Theory
  A theory that posits an individual’s mobility range and actual activity space strongly influence social participation and quality of life. A shrinking life space is associated with heightened risks of functional decline and social isolation [2,3].
• SPOT Framework (Space, Place, Opportunity, Time)
  Developed by Wahl and Lang [8], this framework interprets the life spaces of older adults by integrating physical locations with opportunities and temporal dimensions, thereby linking spatial context to lived experiences.
• Aging in Community (AIC)
  A concept that extends beyond Aging in Place by emphasizing dignity, vitality, and social participation through community-based support systems [9].
• Contextual Gerontology
  An integrative approach that situates older adults within temporal, spatial, and social contexts. It provides a framework for analyzing autonomy, functional abilities, and the fit between individuals and their environments [5].

2. Theoretical Background

2.1. Conceptual Overview

Environmental gerontology provides a foundational framework for understanding the interaction between aging individuals and their environments. Grounded in Lewin’s ecological equation (B = f(P,E)), this perspective emphasizes that human behavior is shaped by the dynamic interplay of personal (P) and environmental (E) factors [10]. Building on this premise, Lawton’s Docility Hypothesis [7] posits that individuals with lower functional capacity are more susceptible to environmental press, making them highly dependent on the quality of environmental support. This hypothesis has been extensively adopted as a conceptual foundation for age-friendly design, emphasizing that environmental adaptation—ranging from assistive devices [11] to home modifications—plays a decisive role in sustaining autonomy and psychosocial well-being.

A widely cited conceptualization within this tradition is the “disability threshold” model, which illustrates how functional competence tends to decline with age while environmental press remains relatively constant—thereby increasing the risk of maladaptation unless compensatory supports are introduced. Subsequent developments in environmental gerontology have expanded this framework toward a more integrative understanding of aging well, encompassing cognitive, affective, and spatial dimensions of adaptation. This theoretical progression underscores that aging is not merely a process of physical decline but a dynamic negotiation between personal capacities and environmental affordances, forming the conceptual basis for the present study’s integrative model.

As illustrated in Figure 1, functional capacity tends to decline with age, but environmental interventions such as home modification can help maintain independence (modified from Grimmer et al. [11]).

Interventions such as assistive devices, housing modifications, and community support can narrow the gap between individual competence and environmental demands, thereby enabling older adults to sustain independence. This theoretical perspective not only provides a rationale for strategies such as Aging in Place (AIP) but also underscores the necessity of broader community-based approaches.

2.2. Life Space Theory

Complementing the docility framework, Life Space Theory explains how mobility and activity spaces shape quality of life and social participation among older adults. Introduced by May, Nayak, and Isaacs [2], the theory conceptualizes life space as a continuum extending from the individual’s bedroom (“zero space”) to the broader urban environment (“fifth space”). Subsequent empirical studies by Peel et al. [3] and Parker et al. [4] have demonstrated that reductions in life space are strongly associated with social isolation, functional decline, and adverse health outcomes.

This study employs the Life Space framework to map how older adults’ spatial experiences evolve across different scales, linking home-based adjustments to collective, community, and urban-level mobility. This expansion allows for interpreting spatial range as both a behavioral and social construct. When integrated with the Docility Hypothesis, Life Space Theory provides a multi-layered interpretive lens that captures the interplay between environmental sensitivity and spatial mobility. Together, these perspectives establish the conceptual foundation for a holistic, multi-scalar model of age-friendly design that spans from the home to the city.

2.3. Integrative Theories (CODA, SPOT, Contextual Gerontology, AIC)

Recent scholarship has advanced a set of integrative frameworks that connect physical and social environments across multiple spatial levels. Wahl and Lang’s SPOT Framework (Space, Place, Opportunity, Time) [8], the CODA Framework (Cumulative Opportunities and Developmental Adaptation) [10], and the perspective of Contextual Gerontology [5] each provide conceptual tools for linking residential, community, and urban contexts in the study of aging. Among these, the CODA model is particularly significant, as it emphasizes how cumulative opportunities across different spatial environments shape functional adaptation and well-being in later life. When combined with Lawton’s Docility Hypothesis, CODA enables a spatiotemporal interpretation of vulnerability and adaptation, offering a more comprehensive lens for understanding the dynamic interaction between older adults and their environments. Together, these integrative theories move beyond single-scale explanations and lay the groundwork for bridging micro-level housing adaptations with meso- and macro-level community and urban strategies. This theoretical convergence prepares the ground for the next step of analysis: identifying the gap that Aging in Community (AIC) is designed to address.

Wahl and Gerstorf [5] proposed an integrative conceptual model in contextual gerontology, highlighting environmental docility and life space as core determinants of aging well. Their framework emphasized the micro-level interaction between individual capabilities and environmental resources as a basis for understanding adaptation in later life. Building upon this foundation, the present study extends the conceptual linkage between docility and life space to the spatial and policy domains, proposing a multi-scalar AIC framework that translates psychological insights into urban and environmental design strategies. This approach thus transforms the notion of “aging well” from an individual adaptation to a collective, spatially embedded process.

2.4. Theoretical Gap

Building upon these theoretical developments, this study positions AIC as an essential theoretical extension and practical evolution of AIP. AIC expands beyond the home to embrace intergenerational interaction, social networks, and communal infrastructure. By embedding AIC within the CODA framework, this study demonstrates how cumulative spatial opportunities support adaptive aging and social participation, bridging temporal adaptation with spatial design strategies.

While AIP emphasizes remaining in one’s home through housing modifications, AIC promotes vitality by fostering community participation, intergenerational interaction, and social integration. By embedding AIC within the CODA framework, this study develops an integrated theoretical model that links the micro (home), meso (community), and macro (urban) levels into a coherent spectrum of age-friendly design strategies. This approach addresses a critical gap in the literature: the lack of a unified framework that connects environmental sensitivity, spatial mobility, and community-based support across scales.

2.5. Korean Contextual Background

Korea provides a distinctive context where the intersection of rapid urbanization and accelerated population aging exposes a fundamental gap between the development of the physical environment and the evolving social structure. Since the 1970s, industrialization and modernization have transformed the nation into what French scholar Valérie Gelézeau [12] famously termed the “Republic of Apartments,” symbolizing a highly efficient yet standardized urban form characterized by dense, homogeneous housing landscapes. These urban environments, while economically productive, were primarily driven by industrial-era imperatives of efficiency and expansion rather than adaptability or inclusivity [13].

Today, this legacy has produced cities with extensive but rigid infrastructures that struggle to accommodate the dynamic needs of a rapidly aging society. Korea’s demographic transformation has been among the fastest in the world, having entered the stage of a super-aged society in 2024 [14]. The coexistence of a technologically advanced yet socially unyielding built environment alongside an unprecedentedly fast-aging population reveals the urgency for new frameworks that integrate environmental adaptability with social participation.

As underscored in reports from the Korea Research Institute for Human Settlements [15], Korea’s urban policy landscape is now at a turning point, shifting from growth-centered development toward human-centered urban renewal. This contextual background not only illustrates the theoretical gap identified earlier but also situates Korea as a living laboratory for understanding how spatial systems and community models can foster sustainable, inclusive aging in rapidly urbanizing contexts worldwide.

At the same time, the concepts of Docility and Life-Space, while not yet widely recognized in Korean academic or policy discourse, provide a valuable interpretive lens for understanding the ongoing transitions in rapidly transforming societies. In Korea, where aging and urban restructuring occur simultaneously, these notions offer a holistic framework that captures both environmental adaptability and social participation as interdependent processes of resilience. Although some elements of this transformation are already visible in the current urban and community practices, the AIC framework can further illuminate how future aging societies might adaptively reorganize their spatial and social systems. In this sense, Korea serves not only as a site of demographic challenge but also as a global living laboratory for envisioning sustainable, inclusive, and resilient models of community-based aging.

3. Research Framework and Method

3.1. Methodological Overview

Older adults experience life across interrelated spatial scales—ranging from home to neighborhood to urban systems—rather than within isolated units. Conventional design approaches have often limited the focus to individual housing or community levels. Representative models include:

• Aging in Place (AIP): Housing modification strategies that enable older adults to remain in their homes despite functional decline.
• Naturally Occurring Retirement Communities (NORC): Residential clusters where older adults live independently but benefit from shared services and social ties.
• Age-Friendly Cities (AFC): Urban-level initiatives coordinated by the World Health Organization to enhance accessibility, participation, and safety for all generations.

While these existing models—AIP, NORC, and AFC—offer valuable starting points, they remain segmented, addressing isolated dimensions of aging without fully integrating social participation, autonomy, and mobility. To address this fragmentation, this section organizes typologies across three spatial levels—housing, community, and city—and examines how each contributes to the integrated Aging in Community (AIC) spectrum.

To overcome this limitation, the present study proposes an extended community-based spectrum that integrates home, neighborhood, and urban contexts. This expanded typological approach emphasizes intergenerational interaction, social participation, and universal design, thereby advancing a more holistic and multi-scalar framework for age-friendly environments.

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Spatial Strategies Based on Housing Modification

Based on Lawton’s Docility Hypothesis [7], older adults with declining functional capacity are more sensitive to environmental challenges, making home environments essential foundations for sustaining autonomy, identity, and quality of life. The Aging in Place (AIP) strategy directly reflects this principle by emphasizing housing modifications that allow older adults to remain in familiar surroundings for as long as possible. Further insight is provided by Gehl’s categorization of human activities [16], which illustrates how the quality of the built environment directly shapes everyday life:

• Necessary activities are essential routines such as errands and grocery shopping, performed regardless of environmental conditions.
• Optional activities: leisure activities, which are highly dependent on the quality of physical space.
• Social activities: interpersonal interactions, which increase significantly when environments are designed to actively support participation.

The concept of life space captures the spatial extent within which an individual performs daily activities, encompassing movements from one’s dwelling to broader social and urban environments. While most empirical studies classify life space into three or fewer zones, this study reconstructs the concept into a five-stage spatial spectrum to better reflect the continuum of aging environments—from the private dwelling (Zero Space) through micro-community, neighborhood, meso-community, and finally to the urban or macro-community (Fifth Space). This gradation allows for finer analysis of how autonomy, participation, and mobility evolve with environmental context.

By aligning this five-stage model with Gehl’s [16] theory of environmental quality and Lawton’s [17] Docility Hypothesis, the study emphasizes that both the quality of the built environment and the radius of life space expansion jointly determine the behavioral freedom and social participation of older adults [16,17]. The conceptual diagram (Figure 2) thus visualizes how higher environmental quality and extended life space collectively enhance autonomy, interaction, and well-being in later life. This framework demonstrates that while necessary activities occur largely independent of environmental quality, optional and social activities depend strongly on supportive spatial conditions. When the built environment enhances comfort, accessibility, and opportunities for interaction, everyday routines evolve from individual maintenance to collective participation. Within this context, housing modifications under AIP address immediate functional needs but remain limited if detached from the broader social and healthcare systems that sustain autonomy. As noted by Pynoos et al. (2012), effectiveness increases when home improvements are integrated with health and social services—indicating that physical and social support systems must co-evolve [18].

This interpretation extends Lawton’s Docility Hypothesis, arguing that sustainable independence arises not from isolated physical adaptation but from environmentally and socially embedded design strategies that link home, micro-community, and neighborhood systems. Such integration exemplifies the core principle of AIC—concept further developed in the typological framework introduced later—where independence is maintained through networks of interdependence. Figure 3 illustrates the conceptual integration of AIP and AIC through dual dimensions of environmental and social expansion. The concentric layers—Home, Micro Community, Neighborhood, Meso Community, and Macro Urban Community—represent the progressive expansion of life space from the individual dwelling to the broader urban environment.

The vertical axis (Scale of Life Space) indicates the spatial expansion of daily activity ranges, reflecting the degree to which older adults can move beyond the home environment toward community and city-level engagement. The horizontal axis (Degree of Healthcare and Social Service Integration) captures the increasing integration of physical and social support systems necessary to sustain independent and connected living. The diagonal arrow labeled “Level of Environmental Quality” represents the interaction between these two dimensions, emphasizing that higher-quality built environments not only enhance mobility but also foster participation and inclusion. As life spaces expand and environmental quality improves, social and healthcare systems become more deeply interwoven, enabling older adults to maintain autonomy, emotional well-being, and intergenerational connectedness.

This model encapsulates the theoretical foundation of AIC: aging is not a process of spatial contraction but one of multidimensional expansion—where physical, social, and service infrastructures converge to support sustainable independence and community participation.

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Community Formation Based on NORC.

Naturally Occurring Retirement Communities (NORCs) evolve organically as demographic concentrations of older adults emerge within existing neighborhoods, rather than through planned development. This model aligns closely with the principles of AIC, as it emphasizes the value of social ties and embedded support systems. NORCs typically provide housing assistance, healthcare access, transportation, and opportunities for cultural and recreational engagement [19]. By addressing daily needs and fostering mutual support, NORCs redefine residential space as a socially interdependent environment. This demonstrates the potential of informal, community-driven networks as foundational units for age-friendly living. These community-scale approaches serve as intermediaries between individualized housing models and broader urban initiatives, bridging personal adaptation with collective participation. Importantly, AIC extends beyond AIP. While AIP focuses on remaining at home, AIC emphasizes sustained dignity and vitality through social capital, exchange networks, and supportive community infrastructure. This redefinition situates AIC as an evolution of AIP rather than a replacement.

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Urban Environment Formation Based on AFC

The World Health Organization’s Age-Friendly Cities (AFC) initiative [20] expands the framework of age-friendly design to encompass the full urban scale, integrating accessibility, inclusivity, and participation. Core AFC strategies include:

• Walkable and accessible public spaces;
• Age-friendly transportation systems;
• Inclusive public services;
• Mechanisms for civic participation.

Viewed through the lens of Contextual Gerontology [5], older adults’ well-being depends on the co-functioning of physical, social, and symbolic infrastructures of the city. However, despite policy adoption, AFC implementation often remains uneven. Integrating AFC domains with the AIC framework can enhance operational coherence, ensuring that urban design aligns with community-level adaptability. Applying Gehl’s framework of necessary, optional, and social activities once again illustrates how the quality of urban design directly supports active, connected, and meaningful aging.

3.2. Conceptual Composition

The three models—Aging in Place (AIP), Naturally Occurring Retirement Communities (NORC), and Age-Friendly Cities (AFC)—offer valuable but segmented insights into age-friendly environments. Each model has advanced important strategies at the home, community, and city levels, yet they remain insufficiently integrated to address the multidimensional realities of aging. The theoretical framework proposed in this study emphasizes that Lawton’s Docility Hypothesis and Life Space Theory should not be viewed as separate models but as complementary elements within a single continuum of adaptive-environmental interaction. To overcome this limitation, the present study synthesizes these models within a spatial spectrum of AIC, linking housing, community, and urban strategies into a coherent continuum.

Table 1. Comparative overview of AIP, NORC, and AFC strategies.

Theoretical Framework	Spatial Scale	Representative Applications	Expansion/ Convergence
Docility (Passive/Physical Adaptation)	AIP (Home-based)	Barrier-free home modification and physical adaptation for older adults	Expanded from individual home modifications to community housing within AIC, linking aging-in-place with sustainable living
AIC (Social–Relational Environment)	NORC (Community-based)	Socially embedded, age-integrated community building	Scaled bidirectionally, from traditional villages to small-scale shared housing and large-scale apartment complexes
Active Aging (Autonomous, Engaged Use of Environment)	Life Space (City-based)	Ensuring access to mobility, urban walkability, transportation, and activity spaces	Expanded to infrastructure-centered large housing complexes and urban environments, ensuring accessibility, comfort, and participation

This table summarizes the origins, spatial bases, and key applications of Aging in Place (AIP), Naturally Occurring Retirement Communities (NORC), and Age-Friendly Cities (AFC). It highlights both their distinct emphases and their emerging convergence within the Aging in Community (AIC) paradigm, illustrating the shift from segmented models toward an integrative framework.

presents a comparative overview of AIP, NORC, and AFC strategies, highlighting their spatial bases, representative applications, and emerging integrative trends. This synthesis demonstrates how theoretical concepts such as Docility, AIC, and Active Aging—originally tied to distinct spatial levels—are increasingly converging to inform more comprehensive and multi-scalar age-friendly strategies. By aligning these frameworks across the micro (home), meso (community), and macro (urban) scales, the table underscores the growing need for integrated and adaptive design approaches.

Drawing on comparative insights from AIP, NORC, and AFC, this section formulates an integrated conceptual framework for age-friendly spatial design across scales. It aims to unify individual, community, and urban contexts within a cohesive AIC model. While Table 1 highlights the convergence of existing strategies across spatial levels, the concept of Extended Community Space captures how older adults’ life ranges are extended through an interplay of spatial infrastructure, social networks, and mobility support. It emphasizes that functional autonomy is socially sustained rather than individually maintained:

• Mobility ranges, which capture older adults’ spatial movements and activity patterns in daily life.
• Social connectivity, which reflects opportunities for participation, intergenerational exchange, and community building.

Together, these domains provide the foundation for constructing a spatial spectrum of AIC. In doing so, they bridge theoretical insights with practical design strategies, offering a coherent basis for sustainable and age-friendly environments. This framework aligns with recent conceptual advances such as Contextual Gerontology and Wahl & Gerstorf’s CODA (Cumulative Opportunities and Developmental Adaptation), extending these temporal perspectives into spatial applications [5]. By connecting CODA’s developmental adaptation with AIC’s spatial progression, this study contributes a novel cross-dimensional interpretation that merges time-based and space-based aging theories. By articulating Extended Community Space in terms of both mobility and social connectivity, the framework moves beyond abstract theorization to highlight measurable and designable elements of age-friendly environments. From an AIC perspective, design strategies should move beyond isolated housing interventions toward an ecosystemic approach that harmonizes physical design, social programs, and policy instruments. This multi-scalar strategy framework serves as a guideline for stakeholders—from architects to urban policymakers—to co-create environments that uphold autonomy, dignity, and participation across the aging spectrum. This conceptual advancement sets the stage for the following section, which develops the Spatial Strategies and Analytical Lens needed to interpret and operationalize these domains across home, community, and urban contexts.

3.3. Spatial Strategies and Analytical Lens

Building on the concept of Extended Community Space, this section advances the discussion by introducing spatial strategies and employing them as analytical lenses. The title reflects the dual role of this study: on the one hand, it maps the strategies that shape age-friendly environments; on the other, it uses these strategies as interpretive tools to understand how theoretical frameworks converge within a unified model of AIC.

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Typological Spectrum of Strategies

Expanding on the synthesis presented in Table 1, the three models—AIP, NORC, and AFC—are positioned along a spatial spectrum that extends from the micro (home) to the meso (community) and macro (urban) levels. Each strategy is examined not only within its original domain but also as part of a continuum that can be repositioned within the broader AIC framework.

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Analytical Lens for Integration

To interpret these strategies, this study employs a composite analytical lens that synthesizes:

• Docility Hypothesis: vulnerability and adaptation to environmental press.
• Life Space Theory: mobility and spatial range as predictors of autonomy.
• CODA and SPOT frameworks: cumulative opportunities and spatiotemporal adaptation.

Figure 4 presents the integrated analytical framework that bridges Docility Hypothesis and Life Space Theory as a multidimensional continuum linking environmental adaptation, spatial expansion, and social integration. The horizontal axis (Community Resources) represents the shift from physical to social dimensions of environmental support, reflecting how resource accessibility transitions from individual housing modifications to community-based and urban-scale infrastructures. The vertical axis (Degree of Functional Activeness) indicates the behavioral and functional capacity of older adults, ranging from passive adaptation to active engagement. The right-hand vertical dimension (Scale of Space) further differentiates the physical scale of the environment—from the home as a small-scale space to age-friendly cities as large-scale environments.

Along the diagonal trajectory, the model maps three key typologies: Home Modification (Docility stage), Naturally Occurring Retirement Community (NORC), and Universal Design Urban Space/Age-Friendly City (UDUS/AFC). This progression illustrates how environmental quality, spatial range, and social resource integration jointly facilitate the transition from Healthy Aging in Place toward Active Aging in Community. Overall, the diagram conceptualizes aging not as a static condition but as an expand in continuum in which physical adaptation, social participation, and environmental quality coevolve to sustain autonomy and community connectedness throughout later life.

This integrative lens enables an evaluation of how AIP, NORC, and AFC function together to reduce vulnerability, expand life space, and foster participation across multiple scales. Figure 4 illustrates this analytical framework, mapping Docility and Life Space along two conceptual axes—physical vs. social and micro vs. macro. The diagram clarifies how each theory has traditionally been applied at distinct levels, while also demonstrating their potential for integration into a coherent framework for age-friendly design.

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Toward Integration

By combining the typological spectrum and the analytical lens, this study lays the methodological groundwork for the introduction of Extended Community Space in the Results section. This step ensures that the proposed concept is not presented as an isolated idea but as a logical extension of established theories and strategies. In particular, it bridges the Docility Hypothesis, Life Space Theory, and integrative frameworks such as CODA and SPOT, demonstrating how they collectively inform a coherent model of AIC. To avoid fragmentation, the empirical illustration of life-space contraction and its implications for AIC is deferred to the Results section (see Figure 8 in Section 4.1 later). There, the analytical integration developed in this chapter is translated into a visual model that contrasts the conventional trajectory of aging with the alternative pathway envisioned through AIC.

3.4. Case Illustration Method

To complement the typological spectrum and the analytical framework, this study employs case illustrations as a methodological tool. Unlike empirical case studies that rely on systematic data collection, the case illustrations presented here function as conceptual exemplars. Their purpose is to demonstrate—visually and descriptively—how the proposed analytical lens can be operationalized across the spatial scales of AIC.

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Selection Criteria

Case illustrations were selected according to three criteria:

• Relevance to the Spatial Spectrum: Each case aligns with one or more stages of the AIC spectrum, spanning home, community, and urban levels.
• Representative Diversity: The set includes small-scale home modifications, mid-scale community housing initiatives, and large-scale urban regeneration projects.
• Illustrative Potential: Cases were chosen for their clarity in demonstrating design principles and social implications, rather than for statistical generalization.

This selective approach ensures that the cases provide conceptual alignment with the study’s framework while showcasing diverse applications.

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Sources of Case Material

The illustrations are drawn from a combination of:

• Documented precedents: architectural and planning projects with relevance to aging and community design.
• Visual illustrations: diagrams and conceptual renderings created to demonstrate extended environments and possible future scenarios.
• Hybrid references: instances where empirical examples were lacking, supplemented with adapted or newly generated images to simulate feasible applications.

This balanced approach allows the study to remain grounded in practice while simultaneously projecting potential innovations.

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Role of Visual Representation

Visual representation plays a crucial role in bridging theory and design. In this study, figures are not empirical data but didactic tools that translate theoretical constructs—such as the Docility Hypothesis, Life Space Theory, and Extended Community Space—into concrete spatial forms. By doing so, they function as communicative devices that make abstract theoretical relationships more accessible to both academic and professional audiences (shown in Figure 5, Figure 6 and Figure 7). Figure 5, Figure 6 and Figure 7 illustrate the methodological modeling of the AIC spectrum, representing the foundational stages (A–B–C) from individual housing to community and urban contexts. These figures establish the theoretical basis for understanding how spatial and social environments are structured within the AIC framework.

Figure 5 presents field-based housing modification projects implemented in rural and declining urban areas, addressing the needs of older adults with diverse physical and sensory limitations. In one case, a tall resident with partial vision loss was provided with a customized kitchen counter and workspace adjusted to her reach and visibility range. These low-cost, context-sensitive interventions demonstrate how environmental barriers can be mitigated through pragmatic design, enhancing autonomy and daily safety. By grounding theoretical concepts in these real-world settings, the study reinforces its empirical validity despite its non-experimental nature.

Figure 6 extends the theoretical framework toward the urban scale, illustrating how community-led regeneration can transform decayed districts into inclusive, age-friendly environments. The upper sequence depicts gradual improvements observed through actual urban regeneration processes—where neglected public spaces were reactivated and physical barriers reduced to enhance social interaction and mobility for older residents. The lower visualization presents an AI-generated predictive model of a future age-friendly city, integrating universal design principles, accessible public amenities, and participatory cultural facilities. Together, these images link empirical field observations with forward-looking urban design concepts, emphasizing the study’s empirical validity and its applicability to real-world and future urban contexts.

At the city-wide scale, age-friendly urban environments have evolved through the integration of universal design principles into public infrastructure and everyday mobility systems. These transformations, observed in Seoul and other global metropolitan contexts, demonstrate how inclusive spatial planning and civic design can actively expand the life space of older adults. By improving accessibility in transportation, pedestrian networks, and public services, such cities promote active aging, safety, and equitable participation. This progression represents the macro-scale realization of the AIC framework, in which inclusiveness becomes embedded within governance, infrastructure, and technological innovation that collectively shape sustainable urban living. The distinctive features are depicted in Figure 7.

Together, these illustrations exemplify how abstract theoretical ideas can be made tangible, and how strategies across scales can be visualized as part of a unified AIC framework.

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Contribution of Case Illustrations

By situating case illustrations within the methodological framework, this study demonstrates how spatial strategies can be understood as part of a continuum of environments that support aging. The cases thus serve to:

• Exemplify scalability: showing how strategies extend from the home to the community and the city.
• Provide visual evidence: clarifying the feasibility of translating theoretical constructs into extended community design.
• Highlight opportunities for innovation: especially in urban contexts where demographic change and social integration are most pressing.

In sum, the case illustrations function as methodological bridges rather than empirical endpoints. Their role is to visualize integrative possibilities and prepare the ground for the conceptual developments presented in the Results.

4. Results

4.1. Extended Community Space: The Intervention Role of AIC

Before detailing the extended community typologies, it is necessary to clarify the intervention role of the Aging in Community (AIC) framework in reshaping conventional aging trajectories. Traditional models of aging typically follow a linear pathway in which older adults move from independent living in the community toward institutional group residences as their physical or cognitive capacities decline. This progression, driven by the logic of protection and control, often leads to a contraction of spatial freedom and a reduction in life quality, despite its intentions of safety and care efficiency.

Figure 8 illustrates how the AIC framework intervenes in this trajectory. Instead of accepting the inevitable shift toward institutionalization, AIC introduces a community-based redirection that sustains aging within local contexts. Through adaptive housing, neighborhood-scale infrastructure, and integrated service delivery, AIC enables older adults to maintain autonomy and participation while remaining connected to familiar environments. This reinterpretation positions AIC not merely as a housing or care model but as a spatial and social mediator—bridging home environments and community systems to delay, or even transform, the move toward institutional care. By strengthening local networks of accessibility, social participation, and support, AIC reframes aging as a continuum of engagement rather than a sequence of withdrawal, laying the conceptual foundation for the subsequent Expanded Community Types 1 and 2 that operationalize this intervention in spatial terms.

4.2. Spatial Spectrum

Building on the concept of Extended Community Space, this study introduces a Spatial Spectrum of AIC that delineates five progressive stages of spatial integration across the micro (home), meso (community), and macro (urban) levels. This spectrum illustrates how older adults’ living environments evolve from private domestic settings to broader urban contexts, while simultaneously embedding opportunities for autonomy, participation, and care.

Table 2. Progressive expansion of spatial strategies across five stages.

Conceptual Axis	Initial Spatial Scale	Current Application	Expansion Flow
Docility	Detached Housing (Home)	Home	Expanded to diverse housing types, including varied unit sizes and small-scale multi-unit dwellings → enabling more flexible AIP environments
AIC	Village/Neighborhood (Community)	Neighborhood	Expanded bidirectionally, from small-scale community housing → to large-scale apartment complexes
Active Aging	Urban Scale	Urban Environment	Expanded daily life territories from large complexes and surrounding urban areas → into extended life spaces grounded in Active Aging

This table details the operational strategies corresponding to each stage of the AIC spectrum. It demonstrates how housing adaptations, micro-community clustering, neighborhood integration, urban connectivity, and extended networks collectively form a coherent, multi-scalar roadmap for age-friendly design and policy. This is conceptual expansion of spatial strategies across the five AIC stages, linking theoretical axes (Docility, AIC, Active Aging) with their spatial applications and directional flow.

shows progressive expansion of spatial strategies across five stages.

• Stage 1: Home-Based Adaptation
  The first stage emphasizes housing modifications that enable older adults to remain in familiar domestic settings despite functional decline. Typical strategies include barrier-free design, assistive technologies, and safety improvements. This stage corresponds directly with Lawton’s Docility Hypothesis, focusing on minimizing vulnerability by reducing environmental press at the household level.
• Stage 2: Micro-Community Support
  The second stage introduces micro-urban clusters, such as co-housing complexes, senior apartments, or localized community centers. These spaces extend beyond individual housing by integrating shared facilities, social ties, and everyday services. At this stage, the Life Space Theory becomes evident, as mobility expands from the home to nearby communal areas, enabling optional and social activities to flourish.
• Stage 3: Community Integration
  The third stage scales up to community-level integration, represented by NORC-type environments. Services such as healthcare access, transportation, welfare support, and cultural programs are provided within the neighborhood context. This stage represents the general-level community of the spectrum, bridging the gap between domestic adaptation and urban infrastructures.
• Stage 4: Extended Community and Inter-Generational Networks
  The final stage extends beyond the immediate city to embrace broader community networks. This includes regional linkages, digital infrastructures, and intergenerational participation platforms. By embedding older adults within wider social and spatial systems, this stage transcends conventional “aging in place” and reframes aging as a community-integrated, future-oriented process. It can be considered as meso-community.
• Stage 5: Urban Connectivity
  The fourth stage highlights city-level strategies derived from the Age-Friendly Cities (AFC) framework. Public transportation, walkable streets, inclusive public services, and mechanisms for civic participation ensure that older adults can remain active and engaged in urban life. At this stage, both Docility (reducing barriers) and Life Space (expanding mobility) converge to sustain autonomy within large-scale infrastructures. It can be considered as macro-community.

While Table 2 illustrates the stage-based progression of the AIC framework,

Table 3. Updated Spatial–Practical Spectrum of AIC.

Type of Spatial Spectrum	Spatial Characteristics & Representative Examples	Theoretical Connections	Explanation & Keywords	Practical Stage (AIC Code) & Examples
Home	Physical living space of an individual household. Elderly single-household renovation; barrier-free design; age-friendly unit layout.	① Docility ② AIP (home)	Physical adaptation, independence, and safety improvements.	Stage 1—Home-Based Adaptation (Plan A) Life-Space Theory: Minimum range; home-based implementation. (Figure 5)
Small Community Housing	Small-scale shared housing with neighborly relations. Co-housing; community-based small units with shared lounges or gardens.	① Expansion of Docility ② Expansion of AIP ③ Expansion of AIC (social relations) ④ Expansion of NORC	Home improvement and micro- community formation.	Stage 2—Home-Based Improvement and Micro-Community Formation (AB) Life-Space Theory: Home-extension stage. Expanded Community Type 1. (Figure 9)
Regenerated Neighborhood Villages	Community revitalization through shared spaces, local services, and intergenerational engagement. Neighborhood-scale environments supporting daily interaction.	① AIC (social participation) ② NORC (neighborhood)	Community restoration and participatory engagement.	Stage 3—Community Vitalization and Improvement (B) Restoration of community networks through local participation. (Figure 6)
Meso- Community/ Integrated Urban Cluster	Neighborhood clusters linked by public facilities and mobility infrastructure. Walkable areas, civic centers, and inclusive public spaces.	① AFC (Active Aging) ② Life Space (urban level)	Mobility expansion and inclusive urban participation.	Stage 4—Meso-Community Integration (BC) Life-Space Theory: City-extension stage. Expanded Community Type 2. (Figure 10)
Macro- Community/Regional Urban Network	Regional and inter-city connections integrating digital, transportation, and welfare infrastructure. Cross-scale connectivity promoting intergenerational solidarity.	① AIC ② Active Aging ③ CODA/ SPOT Integration	Structural embedding, sustainable aging, and intergenerational networks.	Stage 5—Macro-Community Based on Urban Connectivity and Regional Integration (C) Life-Space Theory: Maximum range; macro-level implementation. (Figure 7)

This updated version of Table 3 reflects the corrected definitions for Stages 4 and 5, ensuring conceptual alignment with the latest AIC framework. It illustrates the spatial transition from home-based adaptation to macro-community integration, highlighting autonomy, participation, and intergenerational connectedness.

complements it by aligning these stages with theoretical linkages across spatial scales, ensuring conceptual and empirical coherence. Table 3 Integrated five-stage spectrum of AIC, illustrating the spatial transition from home-based adaptation to urban-scale integration, embedding autonomy, participation, and intergenerational connectedness. Taken together, Table 2 and Table 3 provide a coherent and comprehensive understanding of the AIC framework. Table 2 illustrates the stage-based progression of spatial strategies, while Table 3 demonstrates their theoretical expansion across multiple scales. Together, they clarify how conceptual principles are translated into spatial practice, ensuring that the spectrum is understood not merely as a descriptive sequence but as an integrative model grounded in well-established theoretical foundations.

The five-stage spectrum redefines aging as a process of progressive integration rather than a linear contraction of life space. Each stage builds upon the previous one, maintaining autonomy while embedding opportunities for participation, care, and intergenerational connection. This progression underscores the central argument of the study—that effective aging policy and spatial design must move beyond fragmented approaches such as Aging in Place (AIP), Naturally Occurring Retirement Communities (NORC), and Age-Friendly Cities (AFC).

Instead, it proposes a multi-scalar, integrative framework that connects the home, community, and city as a continuous ecosystem. Within this perspective, the AIC spectrum functions simultaneously as an analytical model for understanding the evolution of aging environments and as a practical guide for policymakers, planners, and designers seeking to implement inclusive strategies across diverse cultural and regional contexts.

To extend this theoretical synthesis, a supplementary summary table is presented in the Appendix A. It consolidates stage-specific strategies and corresponding applications within the AIC framework, integrating theoretical linkages, spatial focuses, and practical keywords into a single comparative matrix. This summary table ensures cross-consistency between conceptual and applied dimensions and serves as a concise reference bridging theoretical discussion and empirical application.

4.3. Case Applications

To demonstrate the applicability of the proposed five-stage spectrum, this study presents a series of illustrative cases across different spatial levels. These cases are not intended as exhaustive empirical validation but as conceptual exemplars, showing how age-friendly strategies can be operationalized in practice. Building upon the foundational stages presented earlier, Figure 9 and Figure 10 extend the existing AIC spectrum toward applied models (AB and BC). These represent the dual expansion pathways centered on community scale (B), demonstrating how AIC evolves bidirectionally—from home-based environments toward urban systems—through integrative and context-specific practices.

• Case 1: Home-Based Modification (Stage 1)
  Residential adaptations—such as barrier-free bathrooms, widened doorways, and assistive technologies—illustrate how older adults can maintain autonomy despite functional decline. As illustrated earlier in Figure 5, such modifications reduce environmental press in accordance with the Docility Hypothesis, thereby supporting independent living at the domestic scale.
• Case 2: Community Housing Model (Stages 2–3)
  Community housing clusters demonstrate how micro-urban environments (e.g., co-housing, senior apartments) evolve into community-integrated systems resembling NORCs. As illustrated earlier in Figure 6, shared facilities, healthcare services, and cultural programs transform residential clusters into socially structured foundations, reinforcing participation and collective well-being.

This Figure 9 presents two complementary examples illustrating how the concept of AIC can be applied in both author-led and independent community housing contexts. The upper case demonstrates an author-participatory project that adaptively reused underutilized urban space to establish a small-scale elderly community housing model, integrating social, ecological, and residential dimensions. The lower case, developed by private initiatives, represents intergenerational community housing that promotes social cohesion and age integration among diverse residents. Together, these examples empirically ground the AIC framework, showing how spatial strategies can nurture community-based care and sustainable coexistence in aging and shrinking cities [21].

• Case 3: Urban Regeneration and Connectivity (Stage 4)
  Urban regeneration projects show how AFC principles can be embedded into large-scale city design, enhancing accessibility, public transit, and walkability. As illustrated earlier in Figure 6, AI-generated visuals complement precedent projects, projecting how age-friendly infrastructures can expand older adults’ life space into broader urban contexts.
• Case 4: Apartment Complex as Extended Community (Stages 2–5)
  In the Korean context, large-scale apartment complexes have increasingly evolved into extended communities that embody the principles of Aging in Community (AIC). These developments integrate residential, commercial, and welfare functions within a single urban fabric, enabling social participation, intergenerational interaction, and neighborhood-based care. The study identifies these complexes as intermediate-scale environments corresponding to Stages 2–5 of the AIC spectrum, bridging individual housing adaptation with community-level integration. The empirical photographs presented in Figure 9 demonstrate how universal design principles and mixed-use infrastructures are embedded in contemporary Korean apartment complexes, transforming everyday living environments into inclusive and sustainable communities. The distinctive features are depicted in Figure 10.

• Case 5: Urban-Level Integration and Policy Framework (Stage 5)
  This case exemplifies how AIC principles can be embedded in long-term urban policy and planning strategies, thereby ensuring both sustainability and inclusivity. Collectively, the cases presented across the micro, meso, and macro levels illustrate the progressive translation of theoretical constructs into practical implementation. By aligning these cases with the five-stage AIC spectrum, the study demonstrates the framework’s scalability and adaptability across spatial and policy domains. Through this integrative perspective, the research highlights how the concept of Aging in Community can evolve into a transferable model for designing inclusive, age-friendly environments that respond dynamically to demographic and social change.
  These applied stages reinforce the theoretical continuum proposed in the methodology, validating the AIC framework as a scalable and context-responsive model for age-friendly community design.

A comprehensive summary of the five-stage strategies within the AIC spectrum is presented in

Table A1. Integrated Summary of Stage-Specific Strategies within the Aging in Community (AIC) Spectrum.

Stage	Spatial Focus	Representative Strategies	Theoretical Linkages	Keywords
Stage 1—Home-Based Modification and Improved Unit Plan(A)	Individual household	Barrier-free design, assistive technologies, safety enhancements	Docility Hypothesis, Aging in Place (AIP)	Environmental press reduction, autonomy, functional support
Stage 2—Home-Based Improvement and Micro-Community Formation (AB)	Co-housing, small-scale collective housing clusters	Shared facilities, neighbor-based services, social ties	Life Space expansion (home → nearby), AIC	Optional and social activity support, proximity-based participation
Stage 3—Community Vitalization and Improvement (B)	Neighborhood/NORC-type environment	Healthcare access, local welfare, cultural and mobility services	NORC framework, meso-level AIC	Community integration, service clustering, participation
Stage 4—Macro-Community Based on Urban Connectivity and Age-Friendly Infrastructure (BC)	City-level and inter-neighborhood infrastructure	Public transportation, walkable streets, inclusive public spaces	AFC concept, convergence of Docility and Life Space	Autonomy, mobility expansion, inclusive urbanism
Stage 5—Extended Community and Intergenerational Networks (C)	Regional and cross-scale linkages	Digital infrastructure, intergenerational participation platforms, policy integration	AIC, Active Aging, CODA/SPOT integration	Intergenerational solidarity, structural embedding, sustainable aging

, illustrating how spatial, theoretical, and practical components are integrated across multi-scalar environments.

5. General Discussion

5.1. Theoretical Implications

The primary theoretical contribution of this study lies in the integration of two foundational frameworks in environmental gerontology—Lawton’s Docility Hypothesis and the Life Space Theory—within the broader paradigm of AIC. Traditionally, the Docility Hypothesis has focused on the micro-scale of housing and personal environments, emphasizing how individuals with diminished competence are more vulnerable to environmental press. By contrast, the Life Space Theory highlights the dynamic expansion and contraction of mobility across spatial zones, ranging from the home to the city. Recent theoretical developments in environmental gerontology have reinforced the need for integrative frameworks that connect environmental adaptation with spatial mobility, emphasizing how aging outcomes are co-shaped by physical, social, and psychological factors [10]. While both perspectives have been widely applied, they have typically been discussed in parallel rather than in combination. This study is conceptual in nature, aiming to construct an integrative theoretical framework rather than to validate it empirically. Future work will operationalize and test the framework using measurable indicators such as life-space expansion, social participation indices, and accessibility scores. Future studies should test the AIC framework through cross-national longitudinal comparisons, integrating both quantitative metrics and qualitative life-space mapping, in line with emerging approaches to urban aging [22].

By bridging environmental adaptation and spatial expansion, this study advances a multi-scalar interpretation of aging in which autonomy and participation evolve through adaptive interactions across domestic, community, and urban scales. Within this framework, the concept of Extended Community Space provides a spatial foundation for AIC, integrating home-based adjustments, neighborhood infrastructures, and urban-level policies as complementary layers of support. This perspective reframes aging as a process of continuity and integration rather than decline and isolation. Figure 11 illustrates this theoretical synthesis. The diagram aligns the Docility Hypothesis and Life Space Theory along intersecting axes—ranging from physical ↔ social environments and micro ↔ macro spatial scales—to demonstrate how AIC bridges environmental sensitivity with mobility expansion. Through this alignment, the figure conceptualizes aging as a progressive continuum from home modification (Docility stage) to Naturally Occurring Retirement Communities (NORC) and Universal Design Urban Space/Age-Friendly City (UDUS/AFC), illustrating the transition from adaptive aging in place toward active aging in community.

The proposed Spatial Spectrum Framework extends this integration by defining a continuum that links environmental adaptability with spatial mobility as the core drivers of autonomy. It serves as an analytical lens for evaluating environments based on their responsiveness to functional diversity—ensuring design inclusivity across the full range from private dwellings to public spaces. This interpretation establishes a unified theoretical foundation for assessing how multi-scalar environmental design sustains independence, participation, and well-being in later life.

5.2. Differentiation from Previous Studies

Previous approaches to age-friendly design have often focused on single spatial scales, leading to fragmented or siloed strategies. AIP concentrated primarily on residential modification, NORC addressed informal social clustering within neighborhoods, and the AFC initiative extended attention to urban-level inclusivity. Although each contributed valuable insights, their development in parallel has limited their ability to respond to the multi-scalar and interconnected realities of aging. For example, AIP interventions often fail to sustain autonomy without community-based services, while AFC policies sometimes overlook the domestic contexts that shape everyday life.

This study differentiates itself by embedding these existing models within a unified spatial spectrum of AIC. Rather than treating AIP, NORC, and AFC as independent or competing paradigms, the AIC framework situates them along a continuum from the home to the city, emphasizing their complementarities rather than their separations. Within this continuum, the concept of Extended Community Space functions as a mediating layer that both consolidates and extends prior approaches—linking micro-level home adaptation, meso-level community networks, and macro-level urban systems into a coherent structure.

In doing so, this study moves beyond theoretical aggregation and proposes a multi-scalar paradigm of aging that integrates environmental gerontology, urban design, and social policy under a single analytical schema. The AIC model introduces the principle of spatial continuity, aligning personal autonomy, community participation, and urban inclusivity as interdependent dimensions of aging. This framework not only repositions previous age-friendly strategies within an integrative logic but also provides practical guidance for policymakers and designers, enabling interventions that are adaptable across diverse cultural and spatial contexts. Ultimately, the AIC paradigm advances a shift from fragmented, scale-specific practices toward a relational model of spatial aging, in which space is understood not as a static container but as an evolving continuum co-shaped by individuals, communities, and cities.

5.3. International and Policy Relevance

The implications of the proposed framework extend beyond the Korean context, offering insights for societies worldwide that are experiencing rapid demographic aging. While Korea’s large-scale apartment complexes provide a distinctive illustration of extended community formation, similar challenges and opportunities are emerging globally. Japan has pioneered neighborhood-based aging initiatives; European welfare states have experimented with intergenerational housing models and age-friendly transportation systems; and North America has promoted the expansion of Naturally Occurring Retirement Communities (NORCs) and community care networks. These diverse experiences collectively demonstrate the convergence of spatial, social, and policy innovations toward inclusive urban aging [10,22], which resonates with the multi-scalar logic of the AIC framework proposed in this study.

Korea’s experience, however, offers more than a contextual reference—it functions as an anticipatory model for global demographic transitions. The country’s accelerated aging trajectory, combined with high-density urban morphology and advanced digital infrastructure, allows the AIC framework to be tested under high-intensity conditions that many other nations will soon face. This makes Korea not only an empirical case but also a theoretical catalyst for understanding how spatial, social, and policy systems can adapt to the pressures of aging societies. Comparable AIC-compatible trajectories are emerging elsewhere—from Japan’s neighborhood welfare models to Europe’s intergenerational housing and North America’s NORC-based care systems—underscoring the framework’s universality and transferability.

The framework is also consistent with global policy agendas. It complements the WHO’s Age-Friendly Cities and Communities (AFCs) initiative by linking built form, mobility, and participation, and advances the UN Sustainable Development Goals (SDGs)—especially SDG 3 (Good Health and Well-being) and SDG 11 (Sustainable Cities and Communities) [23,24]. Despite contextual variations, a common theme persists: aging populations demand integrated approaches that align housing, mobility, and social participation. The AIC spectrum provides a transferable structure for designing such integrative strategies, enabling policymakers and planners to move beyond fragmented, sector-based interventions.

Figure 12 visually synthesizes this theoretical integration, illustrating how AIC operationalizes the Docility–Life Space continuum into actionable design principles. To enhance clarity, we added progression criteria linking each spatial expansion with the WHO AFC domains, ensuring policy-level applicability. It identifies three interrelated domains through which extended community strategies can be institutionalized:

• Infrastructural integration (housing, transportation, digital networks);
• Welfare and healthcare coordination (community-based services, preventive health, and social care);
• Intergenerational engagement (participation platforms, civic inclusion, and cultural programs).

By aligning these domains, the framework reframes aging from an individualized concern into a structural, policy-driven objective. Its adaptability allows advanced welfare regimes to strengthen intersectoral cooperation, while resource-constrained contexts can prioritize scalable interventions such as transit-oriented housing and community-based health services. Furthermore, its emphasis on intergenerational solidarity addresses not only aging but also broader concerns of social cohesion, equity, and sustainable urban development—aligning directly with the United Nations Sustainable Development Goals (SDGs).

By situating the Korean cases—including large-scale apartment complexes, nationwide subway extensions, and free public transportation for older adults—within this global and institutional framework, the AIC model demonstrates how spatial infrastructure and social policy can jointly operationalize age-friendly principles. Korea represents one of the world’s fastest-aging societies, with the population aged 65 and older projected to exceed 46% by 2060 [15]. According to the United Nations [25], Asia will account for over 60% of the world’s population aged 60+ by 2050, while Statistics Korea [15] projects that Korea’s 65+ share will exceed 46% by 2060. These projections position Korea as an anticipatory laboratory for high-intensity aging and underscore the transferability of AIC to other rapidly aging regions.

In Europe, where population decline and rural depopulation are accelerating, intergenerational housing and compact urban regeneration projects resonate with AIC objectives [26]. In North America, NORC-based models highlight the role of informal support networks in sustaining community-based care and aging-in-place opportunities [27]. These cross-national trajectories converge with the World Health Organization’s AFC initiative and the United Nations SDGs—particularly SDG 3 and SDG 11—demonstrating that the AIC paradigm transcends its local origins and offers a transferable strategy for promoting autonomy, inclusion, and social resilience in aging societies worldwide.

Traditional interpretations of the Life Space Index tend to equate aging with spatial contraction. However, this study suggests that life-space quality, not merely physical distance, determines real autonomy and participation. Even when facilities such as healthcare centers or welfare hubs are farther away, perceived accessibility can remain high if universal design transport, safe walking environments, and integrated service linkages exist. In this respect, walkability ensures physical reachability, while the appeal of walking sustains emotional and experiential engagement. The Life Space Index, therefore, should be redefined as a multidimensional construct encompassing physical distance, perceived control, and environmental satisfaction.

This qualitative reinterpretation aligns with recent person–environment scholarship emphasizing perceived accessibility, place experience, and environmental control as key determinants of autonomy and participation in later life [5,28]. By incorporating the complementary notions of walkability and walk appeal, the AIC framework situates mobility within both physical and affective domains—acknowledging that aging well depends as much on perceived control and environmental enjoyment as on distance itself. This methodological synthesis extends the Life Space Index beyond quantitative mobility metrics, establishing it as a multidimensional indicator of spatial experience and autonomy in aging research.

Consistent with integrative models of environmental gerontology, this expanded view of the Life Space Index integrates both quantitative and affective dimensions of movement, reinforcing the multidimensional understanding of autonomy in later life [9,22,29]. These cross-national parallels reinforce the global transferability of the AIC framework and its value for policy harmonization across diverse welfare regimes. The study further expands the discussion of Universal Design (UD) principles as a core foundation of socially inclusive environments. Emerging as a counter-paradigm to the industrial era’s standardized production, UD redefines design as a practice that respects human diversity and fosters equitable participation for all. In rapidly diversifying societies, UD principles—including accessibility, flexibility, and intuitive use—are increasingly recognized as prerequisites for socially integrated urban infrastructures. By embedding UD principles across buildings, transportation systems, and public spaces, cities not only accommodate frail or elderly populations but also empower them to participate fluidly in community life. Moreover, contemporary UD extends beyond physical environments to encompass service design and policy-level inclusion, thereby reinforcing the notion that accessibility and dignity should be integral to every dimension of design. Within the context of this study, UD aligns with the concept of Aging in Community by demonstrating how physical and social systems can evolve toward more active, participatory, and sustainable forms of aging.

5.4. Limitations and Future Work

While this study contributes a novel conceptual framework for understanding and designing age-friendly environments, several limitations must be acknowledged. The analysis is primarily conceptual and illustrative, supported by theoretical synthesis and selected case interpretations rather than systematic empirical data. This approach is valuable for theory building but limits the ability to generalize findings across diverse populations and cultural settings.

Moreover, the research draws heavily on the Korean urban-housing context, particularly large-scale apartment complexes as de facto extended communities. Although this provides a strong testbed for exploring the AIC paradigm, the findings may not be fully transferable to societies with different welfare regimes, housing typologies, or urban infrastructures—such as those in Japan, Northern Europe, or North America [17,26,27]. Cross-national comparative studies are therefore essential to validate the broader applicability of the extended community framework.

Methodologically, this study relies on conceptual modeling and visual representation as analytical tools. While these effectively demonstrate theoretical integration, they do not directly capture lived experiences or measure real-world outcomes. Without empirical validation—through surveys, participatory design workshops, or longitudinal assessments—the practical effects of the AIC framework on autonomy, participation, and well-being remain provisional. To address these limitations, future studies should advance in three major directions:

• Empirical validation of the extended community model in real-world settings, using both qualitative and quantitative methods. Metrics such as life-space expansion, social participation indices, and health outcomes can provide measurable evidence of effectiveness [5,18].
• Comparative international research to examine how AIC principles operate in diverse cultural and policy contexts, identifying both universal patterns and local adaptations.
• Integration with emerging technologies—including smart mobility, digital health monitoring, and AI-assisted community planning—to operationalize extended community strategies in scalable and cost-effective ways.

This study, by design, focuses on conceptual integration and theoretical model development rather than empirical validation. Future research should empirically test the AIC framework across different cultural and spatial contexts, evaluating the adaptability of Type 1 and Type 2 community models. The illustrative cases presented here serve as initial exemplars that demonstrate the framework’s potential for transferability.

The AIC spectrum can also be operationalized through measurable indicators such as the Life Space Index (mobility range and perceived accessibility), participation rates (frequency and diversity of social interaction), and healthcare utilization patterns (preventive versus institutional care ratios) [22,28]. When integrated with spatial data, these indicators enable quantitative assessment of how environmental integration supports autonomy and well-being. This measurable structure provides a pathway for transforming the AIC paradigm from a theoretical construct into an evaluative framework applicable in planning and policy contexts.

Ultimately, advancing the AIC model will require interdisciplinary collaboration among gerontology, urban design, and digital technology. Such integration will refine the model’s multi-scalar mechanisms, support its empirical validation across welfare regimes, and ensure its relevance to emerging paradigms of smart, inclusive, and resilient cities [27,29].

5.5. Concluding Remarks

This study reconceptualizes aging as a process of spatial integration rather than contraction, advancing a multi-scalar framework that unites home, community, and city environments under the paradigm of Aging in Community (AIC). By embedding the principles of Lawton’s Docility Hypothesis and the Life Space Theory into the concept of Extended Community Space, the research demonstrates how autonomy and participation can be sustained through adaptive environmental design across interconnected spatial scales. The originality of this work lies in transforming previously fragmented approaches—Aging in Place (AIP), Naturally Occurring Retirement Communities (NORCs), and Age-Friendly Cities (AFC)—into a cohesive and integrative continuum. This synthesis not only strengthens theoretical clarity but also establishes a practical roadmap for architects, planners, and policymakers to cultivate inclusive environments that mitigate isolation, reduce institutional dependency, and promote intergenerational solidarity.

By situating the Korean experience within a global context, the AIC framework extends beyond conceptual innovation to serve as a strategic model for societal resilience and sustainability amid demographic transition. It positions aging not as a private trajectory but as a collective design and governance challenge, aligning spatial inclusion with social equity and global sustainability agendas. Future research should further validate and refine the framework through cross-national and longitudinal studies, integrating quantitative metrics—such as the Life Space Index, participation rates, and healthcare utilization patterns—with qualitative mapping of lived spatial experiences. Such efforts will advance the empirical foundation for AIC as a transferable model of adaptive, inclusive, and sustainable aging, in line with emerging approaches to urban aging and environmental gerontology [22].

6. Conclusions and Recommendations

6.1. Conclusions

While this study remains conceptual in nature, it establishes a framework for future empirical validation. Subsequent research will incorporate measurable indicators—such as life-space expansion, social participation rates, and health-related quality of life—to quantitatively test the theoretical relationships proposed in this paper. This stepwise approach ensures both conceptual rigor and empirical applicability. This study advances a comprehensive framework for Aging in Community (AIC) by integrating two foundational perspectives of environmental gerontology—Lawton’s Docility Hypothesis and the Life Space Theory—into a unified spatial spectrum. Through this integration, aging is reconceptualized not as a linear contraction of life space but as a process of adaptive spatial integration across multiple scales: the home, micro-community, neighborhood, and city. In conclusion, the integration of Docility and Life Space within the AIC framework demonstrates that these theories, when viewed as a unified continuum, mutually reinforce autonomy, mobility, and social connection.

The introduction of Extended Community Space provides a novel conceptual tool that bridges fragmented strategies such as Aging in Place (AIP), Naturally Occurring Retirement Communities (NORCs), and Age-Friendly Cities (AFC). Rather than treating these models as isolated approaches, the framework situates them as complementary components within a broader continuum. This shift enhances theoretical clarity and offers a roadmap for aligning design and policy across scales. Beyond its conceptual innovation, this study emphasizes the global importance of repositioning aging as a collective rather than an individual challenge. By embedding autonomy, participation, and intergenerational solidarity into spatial strategies, the AIC paradigm contributes to the resilience and sustainability of societies undergoing demographic transition. In this respect, the research underscores that longevity must be matched by inclusion and connectedness, ensuring that older adults remain integral members of their communities.

In practical terms, AIC offers cities a coherent route to deliver the WHO Age-Friendly Cities agenda while advancing SDG 3 (Good Health and Well-being) and SDG 11 (Sustainable Cities and Communities) [23,24]. By embedding spatial inclusion and intergenerational solidarity across scales, it translates demographic challenges into a program of healthy, equitable, and sustainable urban aging. The resulting multidimensional framework refines spatial strategies for aging societies, offering both a theoretical foundation for interdisciplinary research and a practical roadmap for global implementation of age-friendly policies and environments. Ultimately, this study positions AIC as a bridge between personal autonomy and collective well-being, providing a holistic paradigm for designing inclusive environments that enable dignified, community-centered aging.

6.2. Recommendations

Building on these findings, several recommendations are proposed for design practice, policy development, and future research.

• First, design and planning practice should structure environments to support both autonomy and social participation.

• At the home level, universal design and barrier-free retrofits remain crucial.
• At the micro-community level, clustered housing models and shared facilities can transform residential spaces into active community hubs.
• At the neighborhood and city levels, transit-oriented development, walkable infrastructures, and inclusive public spaces should be prioritized to expand older adults’ life spaces and reduce risks of isolation.

• Second, policy development must move beyond single-program interventions to adopt integrated strategies.

• Bundled funding streams that align housing, transportation, welfare, and healthcare can institutionalize AIC principles.
• Interdepartmental governance structures should be created to synchronize planning across agencies.
• Embedding AIC targets into building codes, urban development standards, and welfare programs would ensure sustainability and equity—particularly for vulnerable populations.

• Third, future research and innovation should focus on empirical validation across diverse cultural and policy contexts.

• Comparative international studies can identify both universal patterns and context-specific adaptations of extended community formation.

Integration with emerging technologies—such as smart mobility systems, digital health monitoring, and AI-assisted planning—offers promising pathways to operationalize AIC strategies at scale and with cost-effectiveness.

To support practical implementation, the AIC framework can inform multi-level governance strategies. At the municipal level, it provides criteria for integrating housing retrofits, mobility planning, and welfare delivery. At the national level, it guides funding alignment across ministries responsible for transport, health, and housing. The model’s five-stage spectrum can also serve as a diagnostic tool—helping cities benchmark their progress from home-based support toward fully integrated community systems. This practical roadmap bridges academic theory and policy application.

Taken together, these recommendations underscore that AIC is not only a theoretical construct but also a practical agenda for design, policy, and scholarship. By advancing adaptive and integrative strategies, societies can transform longevity into a source of vitality, resilience, and collective sustainability. In practice, the AIC policy framework can guide national and local initiatives through pilot-based implementation. For example, integrated housing–welfare programs in Seoul or Yokohama could serve as testbeds for cross-sectoral governance. Such place-based demonstrations would allow the AIC model to evolve from a conceptual framework into an operational policy instrument, aligning directly with the WHO Age-Friendly Cities and Communities agenda and the United Nations Sustainable Development Goals (SDG 3 and SDG 11) [23,24].