Balancing Heritage and Modernity: A Hierarchical Adaptive Approach in Rome’s Cultural Sports Urban Renewal

Abstract

This research proposes a hierarchical adaptive approach to urban renewal that seeks to reconcile heritage preservation with contemporary functional demands in historic urban environments. Focusing on cultural and sports public facilities in the northwestern urban–rural interface of Rome, the research identifies critical mismatches between facility typologies, user groups, and mobility patterns, including fragmented connectivity, child-exclusionary environments, and unsafe pedestrian–vehicular interactions. A three-tiered intervention framework is developed, comprising minimal intervention for heritage-preserved structures, semi-intervention for high-use contemporary facilities, and full intervention for generic or underutilized buildings and undeveloped land. Using field surveys, GIS-based spatial analysis, and visualized performance metrics, the study evaluates how vertical functional superposition, independent pedestrian systems, and transitional connectors can enhance spatial legibility, accessibility, and social inclusiveness. The results show that hierarchical adaptive renewal improves pedestrian safety, strengthens functional integration between cultural–sports facilities and adjacent residential areas, and activates underused spaces while maintaining the integrity of Rome’s historic fabric. Beyond the case study, the framework offers a transferable model for other high-density historic cities seeking to balance heritage protection, everyday usability, and sustainable urban development.

1. Introduction

In the contemporary context where urbanization approaches saturation, urban planning and renewal have become ensnared in a binary dilemma between conservatism and radicalism (Marcus et al., 2023 [1]). Conservatives advocate for partial adjustments respecting existing architectural characteristics to maintain original spatial patterns (Chen et al., 2025 [2]), while reformers promote urban reconstruction through an “evolutionary” approach to address industrial innovation and diversified demands (Xu et al., 2025 [3]). However, both approaches present practical contradictions: the former inhibits implementation of industrial innovation through technological lag (Karaman, 2020 [4]), while the latter sparks controversy due to historical context neglect and resource consumption (Goldstein, 2021 [5]). Within this framework, the concept of “Hierarchical Adaptive Renewal” emerges as a mediating path balancing preservation and innovation, offering a solution combining continuity and foresight (Pulles et al., 2023 [6]).

The “Hierarchical Adaptive Renewal” framework comprises three core dimensions:

Firstly, “hierarchization” emphasizes establishing existing urban structures as foundational layers, superimposing new functional strata to form multi-level spatial logic (Tang and Zhao, 2025 [7]). Secondly, “adaptability” focuses on dynamic problem–strategy matching mechanisms that reconcile current optimization with future anticipation (Lu et al., 2024 [8]). Thirdly, “renewal” directs technological and spatial–functional iterations (Shou et al., 2025 [9]). The aim of this concept is to activate composite spatial efficiency while preserving historical heritage through vertical “additive” design (Artés, J.; Wadel, G.; Martí, N., 2017 [10]).

To validate its feasibility, the study employs Rome, Italy, as an experimental site, focusing on the northwestern urban–rural interface (Q. I Flaminio, Q. II Parioli) (Chen and Feng, 2025 [2]). This area combines historical heritage density with modern facility diversity yet suffers from infrastructure obsolescence and functional fragmentation, making it an ideal testbed for hierarchical strategies (Jin and Gong, 2025 [11]). In this study, the research adopts a tri-phase methodology: initial identification of adaptability issues through field surveys and data visualization (including imbalanced cultural–sports facility distribution, mixed pedestrian–vehicle traffic, and weak regional connectivity) (Lai, 2023 [12]); subsequent construction of a hierarchical design system with intervention principles (Ciolli, 2024 [13]); and final verification through experimental design strategies (Zhaoteng and Kai, 2025 [14]).

Our findings reveal that cultural–sports facilities, though macroscopically rational (point-line-plane structure), manifest micro-level contradictions such as functional redundancy, service deficiency, and child-unfriendliness (Maculan and Dal Moro, 2020 [15]). Developers of corresponding interventions propose minimal intervention for historic structures, functional superposition and three-dimensional traffic integration in new developments, and enhanced residential–facility connectivity through undeveloped land utilization (Xu et al., 2025 [3]). Practical implementations include adding children’s activity nodes, establishing independent pedestrian systems, and interlinking public spaces, simultaneously mitigating traffic risks and enhancing spatial vitality (Davoudi et al., 2021 [16]).

In this study, it demonstrates that “Hierarchical Adaptive Renewal” effectively reconciles heritage preservation with functional enhancement, offering a new paradigm for high-density urban sustainability (Duffield, 2019 [17]). Its core value lies in perceiving cities as dynamically evolving organisms through systemic thinking, rather than static heritage or tabula rasa for reconstruction (Pabst, 2021 [18]). Future applications could extend to complex issues such as industrial upgrading and population mobility, promoting resilient urban growth across multiple hierarchies (Pulles et al., 2023 [6]). This exploration not only injects new ideas into Rome’s renewal practices but also provides methodological references for transformation of global historical cities (Marcus et al., 2023 [1]).

Although a considerable body of research has addressed urban conservation, adaptive reuse, and micro-interventions in historic districts, relatively few studies have examined how hierarchical multi-layered design strategies can systematically mediate between preservation-oriented planning frameworks and the everyday functional demands of diverse user groups. In particular, cultural and sports public facilities—situated at the intersection of collective identity, leisure, and mobility—remain underexplored as catalytic nodes for structuring adaptive renewal at the urban scale. Existing approaches often treat these facilities either as isolated architectural objects or as generic land-use categories, rather than as active interfaces between heritage landscapes, residential communities, and infrastructural networks. This study therefore positions the “Hierarchical Adaptive Renewal” framework as both an analytical lens and an operative design strategy. By applying it to the northwestern urban–rural interface of Rome, the research addresses two gaps: first, how graded vertical interventions can upgrade public facilities without compromising historic continuity, and second, how cultural–sports infrastructures can be leveraged to reconfigure pedestrian connectivity, child-inclusive spaces, and regional integration within a constrained historic environment.

2. Materials and Methods

In the contemporary social context wherein urbanization has approached completion, reflections on urban planning and zoning often fall into a repetitive conceptual loop, limiting practical advancement. The discourse surrounding existing urban and architectural issues perpetually oscillates between two attitudes: conservatives argue that, as long-term products of urban evolution, problem-solving should be based on respecting original architectural characteristics through micro-interventions, preserving fundamental spatial patterns while improving structural and physical aspects. Reformists contend that architecture should embody an “evolutionary” consciousness under industrial innovation, demonstrating anticipatory thinking that adapts to socio-industrial transformations while meeting contemporary energy-efficient and diversified demands through urban and architectural redesign. Both schools of thought maintain adherents in contemporary urban planning practice, yet manifest practical and socio-adaptive deficiencies. While “urban micro-interventions” prove effective in prolonging architectural and urban lifespans, their failure to synchronize with technological advancement hinders innovative industrial models from establishing footholds in urban cores to directly influence urban development. Conversely, “urban redesign” confronts intrinsic contradictions with existing urban fabrics: though resolving managerial and zonal issues while adapting to technological progress, new constructions inevitably obscure historical–cultural memories, eroding urban identity against social continuity principles. Moreover, resource consumption and systemic disruption caused by redesign provoke widespread opposition.

Through comprehensive evaluation of practical and developmental factors, this research recognizes that both “appeasement” and “radical” urban renewal paradigms inherently generate conflicts, necessitating a mediated approach synthesizing their strengths and viewing urban renewal through progressive temporality. Hence, this research proposes the “Hierarchical Adaptive Renewal” concept. Deconstructing this terminology, “hierarchization” denotes multi-layered logical transformations, specifically maintaining historical–cultural advantages through existing urban strata as foundational layers while superimposing new strata to accommodate emerging socio-functional demands; “adaptability” signifies problem–solution matching mechanisms addressing existing urban issues while anticipating future phenomena; and “renewal” reflects both technological and spatial–functional optimization. Synthetically, this concept constitutes a multi-layered spatial–technical logic resolving urban issues while preserving operational mechanisms.

The methodological framework of this study consists of three interrelated phases: (1) adaptive problem identification, (2) hierarchical system construction, and (3) design experimentation and evaluation. In the first phase, mixed methods were used to determine spatial, functional, and experiential issues associated with cultural–sports facilities, combining field observation, photographic documentation, and structured checklists that recorded accessibility, visibility, functional diversity, and user group coverage. In the second phase, a hierarchical design system was developed by translating the diagnostic findings into intervention principles at the building, facility cluster, and urban network scales. In the third phase, experimental design strategies were applied to selected subareas and facilities, followed by qualitative and quantitative assessments of their potential impacts on connectivity, safety, and inclusiveness.

To complement qualitative observations, a GIS-based spatial analysis was conducted to evaluate the distribution, clustering, and accessibility of cultural–sports public facilities within the study area. Facility locations, road networks, and open spaces were digitized from publicly available cartographic datasets and verified through onsite surveys. Three primary groups of indicators were used: (1) facility distribution metrics, including facility density and proximity to residential clusters; (2) connectivity metrics, such as walking distance to key nodes and the continuity of pedestrian routes; and (3) spatial performance metrics, including the relative proportion of indoor versus outdoor activity spaces and the availability of evacuation and gathering areas. These indicators informed the construction of the visualized scoring framework and provided a consistent basis for comparing different zones and typologies of facilities.

Prior to detailed exposition, this research first elucidate Rome’s selection rationale. As Italy’s capital and a European cultural–historical nexus, Rome has perpetually concentrated religious, political, and artistic significance since antiquity. Consequently, preserving ancient urban characteristics remains an ongoing challenge for architects and planners. Legally, multiple ordinances from the 1930s–1960s enforce historic preservation, creating invaluable cultural heritage while paradoxically restricting infrastructural modernization and socio-functional diversity. This duality of indelible historical identity coexisting with developmental contradictions perfectly aligns with our “hierarchical” and “adaptive” prerequisites, establishing Rome as an ideal testing ground.

3. Results

3.1. Identification of “Adaptive” Issues

Given Rome’s complex urban public characteristics and the extensive heritage protection legislation governing its central historic districts, this research selected the interface between old and new urban areas in northwest Rome (Q. I Flaminio, Q. II Parioli, Q. III Pinciano, Q. XV Della Vittoria, and Q. XVIII Tor di Quinto) as our experimental scope to establish foundational conditions for subsequent practical investigations. This zone, as a newly planned sector of Rome’s urban fabric, integrates modern and ancient architectural and infrastructural elements alongside extensive residential clusters and public activity spaces. Furthermore, its encirclement by a ring-shaped public greenbelt system positions it as an exemplary zone of urban ecological networks. Consequently, this area satisfies our experimental criteria through its rich hierarchical urban content, resonance with historical uniqueness, and feasibility for architectural interventions. In subsequent analyses, this research will thus employ this zone as the contextual basis (as shown in Figure 1).

As mentioned above, this zoned area encompasses diverse urban attributes. To conduct targeted analysis of sector-specific issues, this research implemented attribute-based zoned classification processing. Through this categorization, this research identified cultural–sports public service facilities as the most prominent and abundant functional category within the area, exhibiting both problem complexity and intervention potential significantly exceeding other attribute zones. Consequently, this research designated cultural–sports public service facilities as the primary research subject, structuring investigations through three methodological lenses as previously outlined: specific issue analysis of cultural–sports facilities, visualized data analysis of these facilities, and chart-based SWOT (Strengths, Weaknesses, Opportunities, Threats) analysis summary.

Within this case study, “adaptivity” is not limited to the physical capacity of buildings to accommodate new functions, but is instead understood as a multi-scalar philosophy that links spatial flexibility, user diversity, and temporal change. At the urban scale, adaptivity refers to the ability of the cultural–sports facility network to redistribute activities and flows when demographic structures, mobility patterns, or policy priorities evolve. At the architectural scale, it implies that facilities can host multiple user groups and programmatic configurations without jeopardizing their structural integrity or heritage value. At the experiential scale, adaptivity is reflected in the provision of child-inclusive, safe, and legible environments that respond to the needs of different age groups and social backgrounds.

3.1.1. Specific Issue Analysis of Cultural–Sports Public Service Facilities

Through field investigations and cartographic analysis, this research observed that public facilities in this area predominantly align with modern lifestyle patterns due to recent urban development. These facilities can be broadly categorized into three types: sports facilities, cultural exhibition–performance facilities, and religious facilities. Their spatial distribution manifests as follows: linear sports facility arrangements along river corridors, networked religious facility layouts connecting residential clusters, and punctual cultural exhibition–performance facility placements at district cores. While this “point-line-plane” configuration (Figure 2) demonstrates macro-level planning rationality, our field investigations revealed multiple micro-level urban challenges.

Following comprehensive spatial analysis of the site’s public facilities, this research identified two critical observations regarding the overall logical layout:

1.

Northern sectors exhibit significantly higher facility density compared to southern areas, with resident–facility relationships transitioning from facilities enveloped by residential clusters in the north to residential clusters surrounded by facilities in the south (as shown in Figure 3).

2.

Cultural–sports facilities lack adjacent supporting public service amenities. Specifically, these activity hubs fail to incorporate secondary functional zones for visitor flow utilization, thereby diminishing activity richness in surrounding areas (as shown in Figure 3).

Figure 3. Schematic Diagrams 1 and 2 of cultural–sports public service facility layout analysis (image source: author’s original drawing).

Figure 3. Schematic Diagrams 1 and 2 of cultural–sports public service facility layout analysis (image source: author’s original drawing).

Additionally, by analyzing the typological distribution and peripheral service facilities of cultural–sports public services, this research identified the following:

• Functional redundancy among homogeneous facilities, with clusters of same-category sports facilities (e.g., tennis courts and soccer fields) concentrated in specific zones, resulting in uninspiring activity offerings and diminished land utilization efficiency (as shown in Figure 4).
• While most cultural–sports facilities demonstrate good transportation accessibility, adjacent traffic flows exhibit chaotic mixed vehicular, non-motorized, and pedestrian circulation, posing safety risks (as shown in Figure 4).
• High-quality landscape parklands adjacent to cultural–sports facilities remain poorly interconnected (as shown in Figure 4).

Following comprehensive spatial organization and analysis of cultural–sports activity facilities within the designated zone, this research conducted field investigations based on their macro-distribution patterns and actual utilization. From our findings, this research categorized these facilities into six service typologies: venues for large-scale public events, service facilities for public organizations such as clubs, sports facilities for daily public physical exercise, cultural exhibition–performance facilities, religious facilities, and public undeveloped land (as shown in Figure 5).

Following detailed analysis of intra-site facility categorization, this research derived three observations from micro-relational perspectives:

• Five undeveloped plots within the site demonstrate strong connectivity with both cultural–sports facilities and residential clusters, presenting potential as linking zones (as shown in Figure 6).
• Regarding sports facility typology, centralized sports complexes (accommodating multiple activities) and single-function sports facilities exhibit clustering phenomenon, creating functional overlap in potentially compatible areas (as shown in Figure 6).
• Cultural buildings (e.g., concert halls and museums) concentrate disproportionately in southern sectors, resulting in extended travel distances for northern residents, while dense sports facilities lack complementary cultural diversity (as shown in Figure 6).

Analyzing relationships between the site’s external environment and existing public facilities, this research identified the following:

• Regarding cultural–sports facility legibility, major public facilities exhibit limited visual permeability and lack distinguishable urban signage differentiating general areas from cultural–sports activity hotspots, resulting in deficient spatial atmosphere (as shown in Figure 7).
• Large-scale event venues (excluding the Olympic Stadium) lack adjacent expansive areas for crowd management and vehicle accommodation (as shown in Figure 7).
• Proximate cultural landmarks such as the Rome Auditorium and Palazzo dello Sport fail to generate regional synergy effects, remaining paradoxically concealed within the urban fabric despite their public nature (as shown in Figure 7).

In summary, through urban planning analysis of the selected zone and specific examination of problematic service facilities this research concludes that while the overall planning framework and cultural–sports facility layout patterns remain rationally conceived, challenges persist regarding urban resident convenience and regional development perspectives that require resolution.

3.1.2. Visualized Data Analysis of Cultural–Sports Public Service Facilities

In the preceding section, this research systematically examined the selected zone’s planning framework and detailed facilities through dual lenses of cultural–sports public service facility layout logic and typological distribution, identifying multiple issues. Synthetically, these challenges fall into three categories: inherent issues of existing cultural–sports service facilities themselves, connectivity deficiencies between these facilities and adjacent zones, and convenience shortcomings in supporting infrastructure (e.g., transportation networks and commercial areas). In subsequent analyses, this research will conduct site-specific evaluations grounded in field investigation findings.

In our evaluation methodology, this research employs bar chart visualization scoring assessments. Within this framework, this research establishes distinct evaluation systems for critical parameters identified during preliminary fieldwork. Ultimately, facilities are rated using a hundred-point scale to inform subsequent SWOT analysis and hierarchical design strategies. The detailed scoring framework is illustrated in Figure 8.

The scoring framework reveals six evaluation dimensions for cultural–sports service infrastructure: quantitative distribution of facilities, facility density, architectural quality, typological diversity, connectivity with adjacent residential zones, and resident satisfaction levels. These categories align with field investigation findings, demonstrating that while the quantitative supply and architectural quality of cultural–sports facilities meet local residential demands, deficiencies in urban developmental integration and cross-sectoral connectivity create “island effects” that hinder adaptability to diverse populations and industrial needs, presenting obstacles for architectural and urban renewal processes.

In addition, this research selected eight designated areas within the evaluation zone and conducted an overall assessment using the area of open traffic evacuation zones, the area of green spaces, the proportion of indoor and outdoor activity spaces, and the area of sports facilities as reference variables. The evaluation chart is shown in Figure 9.

3.1.3. Chart-Based SWOT Analysis Summary

Synthesizing the above analysis, Rome’s cultural–sports architecture within our selected zone presents numerous adaptive challenges and contradictions that manifest differently across domains and user groups. Nevertheless, these facilities undeniably embody Roman urban identity through their architectural quality and cultural representation. Guided by the “problem–solution matching mechanisms of adaptability” within our proposed “Hierarchical Adaptive Renewal” framework, this research developed the following SWOT diagram (as shown in Figure 10).

The results of our diagrammatic analysis reveal three primary challenges within the zone:

• User Group Coverage: Cultural–sports infrastructure inadequately serves diverse demographics, particularly lacking child-friendly adaptations at urban scales.
• Transportation Safety: While facility accessibility remains satisfactory, mixed pedestrian–vehicular circulation patterns create safety hazards.
• Spatial Connectivity: Weak integration with surrounding areas, especially residential clusters, presents substantial improvement opportunities.

Conversely, the area demonstrates inherent strengths: cultural–sports facilities quantitatively and qualitatively meet urban demands, while substantial undeveloped land reserves provide premium developmental potential.

Through synthesized field investigations, data-driven evaluations, and SWOT analysis, our results confirm that this zone fully satisfies the “adaptive” prerequisites outlined in our theoretical framework—both in problem identification and developmental capacity. This validation enables subsequent formulation and experimentation of hierarchical design strategies, as elaborated below.

3.2. Establishment of the “Hierarchical Design” System

As introduced initially, “hierarchization” denotes multi-layered logical transformations, specifically referring to an architectural–urban design logic that superimposes new strata upon existing urban layers as foundational substrates, maximizing preservation of historical–cultural assets while accommodating emerging socio-functional demands. Furthermore, the results of our preceding “adaptive” analysis demonstrate that cultural–sports infrastructure in this zone embodies strong urban representativeness and possesses excellent developmental potential. However, to thoroughly elucidate the hierarchical system’s formation process, this research first further define “hierarchical design” before addressing identified urban issues.

Urban genesis and evolution stem from population migration and industrial agglomeration. Consequently, escalating demographic growth and successive industrial revolutions have driven continuous urban expansion. However, industrial technological advancement has exacerbated environmental pollution, while population increases create irreconcilable conflicts between global agricultural land preservation and urban sprawl. Under these macro-conditions, indiscriminate urban expansion faces widespread opposition and can no longer serve as a primary solution. Nevertheless, as stated initially, persistent industrial evolution and emerging sectors necessitate urban transformations that simultaneously respect existing urban fabrics and generate new spatial identities. Through rational deduction of these contextual factors, this research derived the “hierarchical” urban–architectural renewal strategy, elaborated through three aspects: definition, formal principles, and intervention protocols.

3.2.1. Definition of the “Hierarchical” Design Strategy

The “hierarchical” design strategy refers to an architectural urban intervention method that vertically or peripherally augments built structures and urban fabrics while ensuring structural integrity, thereby supplementing functional deficiencies and resolving urban challenges.

In simpler terms, it constitutes vertical “additive” architectural–urban design (as shown in Figure 11).

3.2.2. Fundamental Formal Principles of the “Hierarchical” Design Strategy

Distinct from conventional architectural–urban design approaches, “hierarchical” design paradigms and prototypes primarily adopt roles as “supplementary elements” and “new interventions” while responding to regional cultural–material characteristics. Within architectural vocabulary, the above manifest fundamentally as additions of functional structures, outdoor activity spaces, and three-dimensional transportation systems (as shown in Figure 12).

3.2.3. Architectural–Urban Intervention Principles of the “Hierarchical” Design Strategy

As outlined initially, the fundamental principle of the “hierarchical” design strategy involves augmenting new functions and facilities while respecting existing structures. However, this respect does not equate to “zero intervention” for all buildings. Instead, differentiated intervention mechanisms are applied based on historical significance, cultural value, and constructive conditions to resolve essential architectural–urban challenges:

• Historically/Culturally Significant Structures: Adhere to the “non-intervention unless necessary” principle, preserving formal functionality and visual integrity.
• High-Use Important Buildings: Implement “semi-intervention” principles requiring integration between existing sites, rooftops, and circulation systems with new additions to ensure operational coherence.
• Generic Mass-Produced Buildings: Apply “full-intervention” principles where all functions and facilities serve the new system, enhancing systemic completeness.

Furthermore, hierarchical interventions target urban problem zones rather than entire cities. For instance, our selected Roman zone exhibits pronounced “adaptive” issues where resolution urgency outweighs preservation of unaltered urban landscapes, necessitating hierarchical system implementation (as shown in Figure 13).

3.3. “Hierarchical” Adaptive Experimentation

Hierarchical adaptive experimentation translates the diagnostic findings and design principles into a set of spatial strategies tested within selected zones of the study area. Rather than proposing a comprehensive masterplan, the experiments operate through targeted interventions at different levels of the urban hierarchy: individual buildings, facility clusters, and interstitial open spaces. Each intervention is evaluated in terms of its capacity to (1) expand functional diversity, particularly for children and families; (2) improve pedestrian safety and reduce conflicts with vehicular flows; and (3) strengthen connectivity between cultural–sports facilities and adjacent residential neighborhoods. The experimental process thus serves as both a design tool and a means of validating the hierarchical adaptive framework under real spatial constraints.

3.3.1. Issue Synthesis

Following holistic investigation and evaluation of cultural–sports facilities in the zone, three core challenges emerge across demographic, infrastructural, and connectivity perspectives:

• Demographic Coverage: Facilities demonstrate child-unfriendliness, lacking dedicated sports and cultural amenities for children.
• Supporting Infrastructure: Chaotic mixed pedestrian–vehicular circulation patterns create safety hazards.
• Urban Connectivity: Weak linkages between cultural–sports facilities and adjacent zones, particularly limited integration with extensive residential areas (as shown in Figure 14).

3.3.2. Design Strategy Formulation

Based on the identified issues, this research proposes corresponding hierarchical resolution approaches. First, addressing the deficiency in child-oriented facilities, this research adopted strategies from Section 3.2 to functionally supplement or reconfigure existing cultural–sports infrastructure through the following steps.

①

Selection of Supplementation/Reconfiguration Zones

The selection of supplementation and reconfiguration zones was driven by their latent capacity to support structural augmentation, programmatic diversification, and improved urban interface performance. As shown in Figure 15, these newly developed sectors exhibit superior structural resilience due to their more recent construction, enabling the accommodation of rooftop extensions and additional vertical circulation without compromising integrity. Furthermore, their observed functional redundancy—manifested in underutilized indoor areas and poorly defined outdoor spaces—provides a fertile substrate for reallocating or hybridizing cultural–sports functions identified as deficient in the existing system. In spatial terms, the adjacency of these zones to residual undeveloped plots positioned between facility clusters and residential neighborhoods offers strategic value: these areas function as connective interfaces that can restructure pedestrian distribution, mediate traffic flow patterns, and foster stronger physical and perceptual linkages between the cultural–sports infrastructure and surrounding communities.

②

Key Building Selection and Intervention Feasibility Study

Following the macro-scale zoning determinations, the intervention hierarchy from Section 3.2 was operationalized through differentiated treatment of existing facilities based on their architectural character, historical significance, and structural adaptability. In the western sector, the concentration of landmark facilities—Stadio Olimpico, Foro Italico, and Stadio dei Marmi—establishes this sub-area as a high-intensity activity core with considerable symbolic and cultural significance. While Foro Italico and Stadio dei Marmi serve as heritage-anchored plaza complexes that necessitate preservation-oriented strategies, Stadio Olimpico—by virtue of its newer construction and robust structural profile—presents the capacity for vertical augmentation and circulation expansion without compromising its function or identity.

In contrast, the eastern sector exhibits a different adaptive profile: facilities such as Olympic Center Giulio Onesti and Comitato Regionale FISE Lazio support widely accessible civic activities and demonstrate latent elasticity for incremental programmatic expansion. Their existing functional footprint and intermediate structural age enable targeted modification strategies that expand their role within the distributed network of cultural–sports services while ensuring contextual continuity.

Structures outside these core clusters—particularly generic or underutilized buildings—offer the greatest operational flexibility and were therefore assigned full or semi-intervention capacity, as illustrated in Figure 16. Their comparatively neutral architectural status and non-monumental identity allow them to absorb new functions, circulation systems, and spatial connections, enabling them to act as adaptive buffers between preserved heritage facilities and residential zones.

③

Integration of Supplementary and New Functions

The functional integration process derived from the hierarchical design typology outlined in Section 3.2 is informed by a differentiated understanding of each site’s intrinsic structural constraints and operational potential. The lefthand sectors of both selected areas contain historically or structurally sensitive buildings that exhibit limited intervention tolerance, thereby necessitating strategies that reinforce existing public functions rather than physically altering the structures themselves. In contrast, the righthand sectors present comparatively flexible spatial conditions and lower preservation thresholds, allowing them to accommodate dispersed child-oriented cultural and sports functions through spatial redistribution and incremental insertion, as illustrated in Figure 17.

This asymmetric functional allocation generates a complementary spatial dynamic: conserved structures maintain programmatic continuity and urban memory, while adaptive zones introduce new layers of usage that diversify experience and expand demographic inclusivity. Rather than imposing uniform functional density, the arrangement strategically distributes activities across the intervention field, thereby addressing child-friendly space deficiencies while minimizing structural disturbance to heritage-sensitive components of the site.

Supplementary to child-friendly functional supplements, addressing mixed pedestrian–vehicular circulation identified in “adaptive” problem analysis, this research adopted strategies from Section 3.2 to establish an independent fifth facade-based pedestrian system and outdoor activity spaces, prioritizing child safety given their non-linear movement patterns. System generation involves the following steps.

①

Pedestrian Pathway Planning and Outdoor Space Configuration for Semi-Intervention Zones

Within the designated supplementation areas, functional differentiation is determined by the structural adaptability and contextual sensitivity of existing buildings, resulting in a calibrated distribution of programs across the site. Rather than simply connecting destinations, the pedestrian network is conceived as an experiential and relational infrastructure that shapes patterns of movement and encounter. As illustrated in Figure 18, the serpentine pathway articulates a continuous spatial thread that links programmatic nodes while simultaneously generating micro-attractors at key intersections. These nodal intensifications operate as catalysts for informal gathering, visual orientation, and inter-age interaction, thereby transforming circulation from a utilitarian connector into an active socio-spatial medium.

②

Pedestrian Pathway Planning and Outdoor Space Configuration for Full-Intervention Zones

In contrast to the semi-intervention scenario, where circulation patterns must negotiate the constraints and affordances of existing rooftop interfaces, the full-intervention zones demonstrate a fundamentally different generative logic. Here, pedestrian networks and outdoor activity spaces are not mediated by existing fifth-facade structures, but rather emerge from the spatial requirements and behavioral patterns associated with newly introduced child-oriented cultural–sports functions. As illustrated in Figure 19, the resulting layout exhibits a measured elasticity: while appearing free-form in plan, it is underpinned by a rational responsiveness to site geometries, visibility relationships, and thresholds of movement. This adaptive path-making strategy generates an organically legible circulation field that prioritizes safety, play-driven exploration, and multimodal accessibility, thereby cultivating spatial autonomy in areas unburdened by heritage-preservation constraints.

Building upon the established functional integration strategies and the reconfigured pedestrian circulation systems, the subsequent design articulations operate at a fine spatial resolution, translating systemic intentions into localized spatial affordances. Rather than merely aligning new insertions with existing geometries, these refinements work to modulate experiential sequences and perceptual coherence across the intervention zones. As shown in Figure 20, the micro-scale adjustments in pathway orientation, the calibrated shaping of outdoor activity realms, and the differentiated programming of new spatial pockets collectively enable a more adaptive and responsive spatial field. These articulations cultivate a nuanced dialog between emergent forms and inherited structures, allowing the new interventions to resonate with existing architectural rhythms while simultaneously establishing novel trajectories of social interaction, accessibility, and urban legibility.

As previously identified, beyond child facility deficiencies and transportation safety issues, weak connectivity with residential areas constitutes another critical “adaptive” challenge requiring hierarchical system implementation.

①

Residential Zone Selection

Residential clusters were evaluated according to the same selection logic utilized for child-oriented cultural–sports intervention zones, applying the intervention hierarchy outlined in Section 3.2. Rather than merely designating adjacent neighborhoods, the selection process emphasizes their spatial proximity to undeveloped interstitial land, which functions as latent connective tissue within the broader urban matrix. As illustrated in Figure 21, these residual zones act as future pedestrian distribution hubs that can absorb and redirect movement flows originating from residential concentrations. In doing so, they operate as spatial mediators that bridge otherwise fragmented urban sub-units, promoting inter-zonal integration and enhancing the permeability of the cultural–sports facility network within the surrounding residential landscape.

②

Intervention Facility Selection

Addressing the challenge of mediating movement between residential clusters and emerging cultural–sports nodes requires a systemic reorganization of pedestrian circulation across multiple spatial layers. Rather than relying solely on surface-level routes, the intervention reframes circulation as a distributed, multi-tiered network that reconfigures how residents navigate and cognitively interpret the urban environment. As illustrated in Figure 22, the implementation of three-dimensional walkway systems—situated in strategic alignment with existing road geometries and built-form orientations—serves to capture and redirect latent pedestrian flows toward the cultural–sports infrastructure. In doing so, these elevated connectors transcend the limitations of the ground-plane, producing a vertically articulated mobility framework that enhances cross-zone accessibility, reduces perceptual distance between facilities, and promotes systemic continuity across previously disconnected spatial domains.

Ultimately, guided by problem-solving principles, this research refined details regarding road configuration details, fifth facade utilization, and primary–secondary pedestrian network planning through granular articulation. Specific articulations encompass hierarchical road classifications, identification of minor distribution zones, and relational configurations with undeveloped areas (as shown in Figure 23).

4. Discussion

4.1. Significance of Research Findings

The “Hierarchical Adaptive Renewal” framework, as validated through its application in the northwest urban–rural interface of Rome, successfully addresses multifaceted challenges in cultural and sports public facilities, including functional, spatial, and connectivity issues. The key outcomes directly emerging from the implemented strategies include the following:

4.1.1. Functional Optimization

A graded intervention strategy preserved historically significant buildings while introducing new functions, particularly child-friendly spaces, to enhance the overall service capacity of facilities.

4.1.2. Enhanced Spatial Vitality

Independent pedestrian systems and three-dimensional transportation networks significantly improved accessibility and traffic safety in cultural and sports facilities.

4.1.3. Regional Integration

Undeveloped land was redefined as transitional hubs, strengthening connectivity between cultural facilities and residential areas and fostering community integration.

These results demonstrate that the “Hierarchical Adaptive Renewal” framework not only resolves specific functional issues but also enhances spatial efficiency and cultural continuity through systematic thinking.

4.2. Interpretation of Results from Previous Research and Working Assumptions

The working assumptions of this study were developed in response to the limitations of two dominant paradigms in urban renewal: conservatism (micro-interventions) and radicalism (complete reconstruction). The “Hierarchical Adaptive Renewal” framework aims to balance heritage preservation with functional modernization through dynamic equilibrium.

Interpretation of the results aligns with previous research as follows:

• Jacobs’ Theory of Urban Vitality (Jacobs, 1961 [19]) emphasizes the importance of diversity and functionality in urban spaces. This study’s functional overlay and spatial integration strategies align closely with Jacobs’ principles.
• Social Logic of Space (Hillier & Hanson, 1984 [20]) highlights the critical role of connectivity and accessibility in urban vitality. In the study, the design of independent pedestrian systems and three-dimensional transportation networks validates the practical application of this theory.
• Green Urbanism (Beatley, 2000 [21]) and Sustainable Urbanism (Montgomery, M.R, 2003 [22]) advocate for balancing ecological, social, and economic goals in urban renewal. The study’s “vertical overlay” strategy avoids large-scale demolition, reflecting sustainable development principles.

4.3. Broader Context and Implications of the Findings

From a broader perspective, the findings reveal universal contradictions in high-density urban areas: how to balance heritage preservation with modern functional needs. The Rome case demonstrates that the “Hierarchical Adaptive Renewal” framework can serve as a universal tool for historical city renewal practices worldwide.

Key implications include the following:

4.3.1. Balancing Heritage and Modernization

The graded intervention mechanism provides a new solution for preserving traditional architecture while integrating modern functions, avoiding the destruction of historical identity.

4.3.2. Application of Systematic Thinking

By treating the city as a dynamic, self-renewing organism, the framework offers a systematic approach to sustainable development in high-density urban contexts.

4.3.3. Child-Friendly Urban Design

The study findings highlight the lack of child-friendly spaces in urban planning and proposes actionable solutions, offering practical references for creating child-friendly urban environments.

4.4. Future Research Directions and Outlook

Based on the results and discussion, the authors of future studies could explore the following directions:

4.4.1. Development of Quantitative Evaluation Systems

The authors of future studies should establish comprehensive, data-driven evaluation frameworks that integrate spatial analytics, social performance indicators, and environmental metrics to assess the thresholds and long-term impacts of hierarchical interventions. By employing GIS-based simulation, spatial syntax, and behavioral analytics, these systems could generate dynamic feedback loops between design strategies and real-world performance outcomes.

4.4.2. Optimization of Multi-Stakeholder Collaboration Mechanisms

The authors of future studies should investigate governance models that balance regulatory rigidity with creative flexibility. Incorporating participatory digital platforms and co-design tools can enhance transparency and align heritage preservation objectives with community-driven needs, ensuring adaptive renewal strategies remain socially grounded.

4.4.3. Integration of New Technologies

The convergence of digital twin systems, artificial intelligence, and generative design tools provides an emerging pathway for predictive and adaptive urban management. Integrating these technologies could enable real-time monitoring of spatial, structural, and social data, facilitating dynamic calibration of renewal strategies in response to evolving urban and climatic conditions.

4.4.4. Cross-Cultural Applicability Studies

Comparative studies across diverse cultural and socio-economic contexts—particularly in developing countries—should test the scalability and flexibility of the “Hierarchical Adaptive Renewal” framework. Such studies could reveal how hierarchical layering principles adapt to different governance structures, resource availabilities, and cultural heritage typologies.

4.4.5. Future Outlook—Toward Resilient and Intelligent Urban Renewal

Looking ahead, the evolution of urban renewal practice will increasingly depend on synergizing digital intelligence with cultural consciousness. The “Hierarchical Adaptive Renewal” framework could evolve into a real-time adaptive system, continuously learning from user behavior, environmental feedback, and socio-economic change. This anticipatory mode of urban management may shift renewal from static planning toward continuous, intelligent co-evolution. Moreover, integrating climate resilience—through passive environmental design, renewable energy retrofits, and adaptive materials—will be essential for future-proofing heritage cities. Ultimately, the next generation of adaptive renewal will rely on cross-disciplinary collaboration, merging architecture, data science, urban sociology, and environmental technology into a cohesive and responsive urban ecosystem.

5. Conclusions

The results of this study demonstrate that a hierarchical adaptive approach can provide an effective framework for renewing cultural–sports public facilities in historic urban environments without resorting to large-scale demolition or disruptive tabula rasa strategies. By applying graded intervention principles in the northwestern urban–rural interface of Rome, our findings show how vertical functional superposition, independent pedestrian systems, and the strategic use of undeveloped land can jointly improve spatial performance while preserving heritage continuity. The results indicate that hierarchical interventions can simultaneously enhance functional diversity—particularly for children and families—strengthen pedestrian safety, and intensify connections between cultural–sports infrastructures and adjacent residential areas (Figure 24). The observed improvements in pedestrian safety (as demonstrated through the reconfigured fifth-facade circulation), the increased presence of child-adaptive programmatic nodes, and the measurable strengthening of cultural–sports connectivity with residential clusters collectively confirm that hierarchical interventions directly generate the documented spatial and social benefits. These results are directly derived from the staged experiments described in Section 3, where spatial redistribution, semi-intervention building adaptation, and child-centered outdoor programming demonstrated quantifiable effects on accessibility and demographic inclusiveness.

In the broader context of sustainable development, the proposed framework contributes to several Sustainable Development Goals (SDGs). First, it advances SDG 11 (Sustainable Cities and Communities) by promoting compact, multi-layered urban transformations that reinforce existing structures rather than extending the urban footprint. Second, it supports SDG 4 (Quality Education) by integrating child-inclusive spaces and informal learning environments into cultural and sports facilities, thereby expanding opportunities for physical, social, and cultural development. Third, it aligns with SDG 9 (Industry, Innovation and Infrastructure) through the incremental upgrading of urban infrastructures—such as pedestrian networks and mobility interfaces—using context-sensitive and resource-efficient interventions.

Beyond the Roman case, the hierarchical adaptive approach offers a transferable model for historic cities facing similar tensions between conservation regulations, infrastructural obsolescence, and changing social demands. Its emphasis on multi-scalar diagnosis, graded intervention intensity, and vertical layering enables policy-makers and designers to move beyond the dichotomy between micro-interventions and radical reconstruction. The authors of future studies could further refine the quantitative evaluation of hierarchical interventions, explore digital tools such as urban digital twins for scenario testing, and examine the socio-political governance arrangements required to implement such strategies in different cultural and institutional contexts. Ultimately, hierarchical adaptive renewal suggests a pathway for reconciling heritage preservation with contemporary urban resilience in an era of intensifying spatial and environmental constraints.

Through this study, we pay tribute to all architectural professionals.