BETWEEN: A Threshold of Sustainable Urban Architecture

  By Altunay Ejdar and Sude Özselçuk

Shortlisted Entry – Live Green Competition  

BETWEEN is an architectural exploration that rethinks the boundary between the expanding urban fabric and the serenity of surrounding nature. Conceived by Altunay Ejdar and Sude Özselçuk, the project investigates how sustainable urban architecture can dissolve rigid separations between built and natural environments, forming a cohesive threshold of coexistence. The design seeks to embody the principle of unity — where nature and city not only meet but interweave through spatial, structural, and social design strategies.

Context and Concept: Defining the Threshold

The project site lies at a crucial edge — a point of transition between dense urbanization and natural landscape. Instead of treating this boundary as a line of division, the designers approached it as a living threshold, capable of facilitating exchange, blending, and balance. The urban side offers vitality and density; the natural side provides openness and calm.

Through a detailed site analysis, the team identified opposites (city and nature), pathways of interaction, and zones of transition that could guide the architectural form. The design process followed five key steps:

1. Identify the Area – Mapping the site and its contextual influence.
2. Identify the Opposites – Defining the contrasting zones of urban and natural fabric.
3. Identify the Threshold – Locating the space where both could intersect meaningfully.
4. Develop Design Approaches – Integrating structure, program, and circulation across the threshold.
5. Specify the Path – Blending the opposites through spatial and social continuity.

This method allowed the project to transform from a site boundary into a dynamic ecological corridor, where human interaction, green infrastructure, and modular housing coexist.

Architectural Strategy: Blending Opposites

The architectural strategy of BETWEEN revolves around a flexible system of modular housing units, service cores, and social interfaces. Each component contributes to the project’s central goal — creating a resilient and adaptable structure that connects people, environment, and city.

• Service Units: Functioning as the project’s backbone, these units accommodate essential services such as stairs, elevators, and utilities. They serve as connectors, linking different layers of the design and organizing vertical and horizontal movement.
• Amphitheater: Positioned at the primary entrance, the amphitheater acts as a community hub where people gather, perform, and interact. It serves both as an access point and as a shared social space that strengthens urban engagement.
• Glass Units: Semi-transparent glass structures bridge underground and ground-level spaces. They mediate light, define circulation paths, and visually connect indoor and outdoor realms — a physical metaphor of transparency between city and nature.

Form, Function, and Flexibility

The modular system is designed with adaptability at its core. Units can accommodate varying needs — from individual to group living — ensuring both flexibility and inclusivity. The structural logic allows reconfiguration over time, making the project inherently resilient to urban growth and environmental change.

The design also incorporates open courtyards, pedestrian pathways, and recreational landscapes that enhance microclimatic comfort and biodiversity. By rethinking how architecture interacts with context, BETWEEN evolves as a living organism — responsive to both human and ecological needs.

Spatial Experience: Living the Threshold

Circulation is organized to create a seamless spatial narrative — users move through gradients of openness and enclosure, shifting between communal and private zones. The design encourages exploration; each turn reveals new interactions between built form and green void.

Those traversing this threshold experience not a boundary, but a continuum — a place that merges architecture, landscape, and life. The project’s orange-toned modular units stand as a symbolic contrast to the green landscape, visually reinforcing the dialogue between constructed and natural systems.

Sustainability and Urban Integration

As a sustainable urban architecture prototype, BETWEEN employs environmentally conscious strategies at both design and material levels. Prefabricated modules minimize construction waste, while passive design principles optimize natural ventilation and daylight.

The green zones woven through the site improve biodiversity and microclimate regulation. Public spaces double as stormwater catchment areas, contributing to the ecological resilience of the neighborhood. Through its integration of modularity, adaptability, and ecological sensitivity, the project demonstrates how architecture can facilitate symbiosis between city and nature.

Architecture as a Mediator

BETWEEN is more than a housing proposal — it’s a philosophy of connection. It envisions a future where architectural boundaries evolve into shared spaces of interaction and reflection. By merging the built and the organic, it redefines sustainability not as a static goal but as a living process of balance.

In doing so, the project becomes a benchmark for the next generation of sustainable urban architecture, inspiring cities to grow with nature rather than against it.