The Light Of City: Adaptive Reuse Urban Design

Adaptive reuse urban design has emerged as one of the most effective strategies for transforming neglected infrastructure into vibrant public assets. The Light of City, Inject Light into the ‘Crack’, a project by Nanjing Forestry University and Di Xiao, exemplifies this approach by reimagining the abandoned La Petite Ceinture railway in Paris. Shortlisted in the Salut Paris competition, the proposal addresses the spatial, cultural, and ecological fragmentation of the site, redefining it as an active urban corridor.

The project frames the railway as a “crack” within the city fabric, not as a void to be erased, but as a latent spatial opportunity. Through strategic interventions, the design introduces light, activity, and cultural programming to transform this forgotten infrastructure into a dynamic public realm.

Context: The Forgotten Infrastructure of Paris

La Petite Ceinture once functioned as a vital infrastructural loop around Paris. Over time, its relevance diminished, leaving behind a linear void embedded within dense urban fabric. This residual space now exists in a state of temporal suspension, disconnected from the city’s contemporary rhythms.

The proposal interprets this condition not as decay, but as potential. By positioning the railway as an urban “crack,” the design recognizes both its physical separation and its capacity to reconnect fragmented urban systems.

Concept: Injecting Light into the Urban Void

At the core of the project lies a clear conceptual framework: introducing light as both a physical and cultural catalyst. The intervention operates across three primary dimensions:

1. Daylight Activation: Strategic spatial openings and landscape insertions allow sunlight to penetrate the recessed railway corridor, transforming it into an inviting public environment.
2. Night-time Illumination: Artificial lighting enhances safety and usability after dark, extending the temporal relevance of the site.
3. Cultural Light: Programming such as exhibitions, performances, and informal gatherings introduces symbolic “light,” embedding cultural vibrancy into the space.

This multi-layered interpretation of light positions the project as both an environmental and socio-cultural intervention.

Spatial Strategy: Reconfiguring Linearity

One of the primary challenges of the site is its strict linearity. The design responds by subdividing and reconnecting the space through two parallel systems:

• Ecological Continuity: Green corridors extend beyond the site boundaries, linking the railway to adjacent natural systems.
• Urban Accessibility: Vertical connections such as stairs and ramps integrate the lower railway level with the upper street network.

Rather than resisting the linear nature of the site, the proposal leverages it to create a continuous sequence of spatial experiences. Programmatic nodes punctuate this linearity, introducing variation and intensity along the corridor.

Programmatic Framework: The Urban Living Room

The project envisions the site as an “urban living room,” accommodating diverse user groups including residents, tourists, and immigrant communities. Key programmatic elements include:

• Weekly markets and second-hand bazaars
• Art exhibitions and cultural events
• Informal gathering spaces and seating areas
• Performance zones and open-air theatres

This layered programming fosters social interaction while reinforcing the identity of the site as a cultural platform.

Architectural Language: Modular and Container-Based Systems

The architectural strategy adopts a modular, container-based system to ensure flexibility and cost efficiency. These structures:

• Enable rapid assembly and reconfiguration
• Support mixed-use functions such as retail, exhibition, and community spaces
• Integrate green roofs to enhance environmental performance

While pragmatic, this approach also introduces a distinct visual identity, emphasizing temporality and adaptability within the urban fabric.

Sustainability and Cost Efficiency

The project integrates multiple sustainable strategies aligned with adaptive reuse urban design principles:

• Permeable Paving: Enhances rainwater infiltration and reduces flooding risk
• Local Planting: Minimizes maintenance while reinforcing ecological resilience
• Recyclable Materials: Reduces environmental impact of construction
• Modular Systems: Optimizes construction costs and lifecycle adaptability

These strategies ensure that the intervention remains both economically viable and environmentally responsive.

Social Integration and Accessibility

A key strength of the proposal lies in its inclusive design approach. By incorporating barrier-free access, elevators, and ramps, the project ensures accessibility for all users. The integration of public programming further supports social cohesion, particularly through initiatives that encourage interaction between local residents and immigrant communities.

Juror Feedback: Critical Reflections

The project received mixed responses from the jury, highlighting both its strengths and limitations.

Fuensanta Nieto noted the value of the proposed entrance strategy, emphasizing its potential to reconnect the city with the lower-level spaces. However, she identified a lack of clarity in the treatment of the central space, suggesting the need for stronger spatial definition.

Rachel Luchetti critiqued the container-based approach, describing it as uninspiring. This feedback points to a broader architectural debate between pragmatic modularity and expressive spatial design.

These critiques underscore the importance of balancing functional efficiency with architectural innovation in adaptive reuse projects.

The Light of City demonstrates how adaptive reuse urban design can transform neglected infrastructure into meaningful public space. By leveraging light as a conceptual and operational tool, the project reactivates La Petite Ceinture as a cultural, ecological, and social corridor.

Despite critiques regarding its architectural expression, the proposal succeeds in addressing key urban challenges including connectivity, inclusivity, and sustainability. It positions the abandoned railway not as a relic of the past, but as a catalyst for future urban life.

In doing so, the project contributes to a broader discourse on how cities can reclaim their forgotten spaces and reintegrate them into contemporary urban systems.