Cobbled plaza beneath a concrete viaduct, with red-clad timber housing modules hung from the viaduct beams on steel cables, café tables and umbrellas, and people walking past

Competition Project

Nexus

[ˈnɛk.sʊs]

Year: June 2025
Classification: Competition Project
Status: Competition entry
Team: Gökalp Kalfa
Zehra Çelik (opens in a new tab)
Denizhan Şallı (opens in a new tab)
Göktuğ Ünlü (opens in a new tab)
Organizer: Buildner & Kingspan, Micro Home 2025
Area: 25 m²
Recognition: Honorable Mention, 2025

SHEAFS Diagram

Derived from the Latin root "nectere", meaning "to bind, to connect," Nexus encapsulates the project's core conceptual approach through a multifaceted metaphor. More than just a housing solution, Nexus is a system that forges strong relationships within the urban fabric, offering a flexible and sustainable model that integrates individuals, cities, and spatial structures. It provides an opportunity for migrants and those struggling with housing to establish direct connections with the city, while modular housing units foster new social bonds. Structurally, these micro-homes are anchored to viaduct beams with steel cables, transforming viaducts from mere transportation infrastructures into active living spaces. Nexus serves as a transformative mechanism that redefines urban strategies for the future, operating independently of traditional infrastructure while reinforcing social and physical connections through architecture.

Adaptive Urban Living for Inclusive Cities

More than just a housing solution, Nexus prevents urban spaces from becoming obsolete while fostering a new social fabric. By transforming viaduct underpasses into safe, sustainable, and accessible housing, it enables migrants and low-income groups to establish stronger connections with the city. In doing so, Nexus not only facilitates social integration but also pioneers a more inclusive urban housing model.

Designed as a cyclical system, Nexus ensures adaptability and sustainability through three key phases: (1) Assembly and Reuse – Pre-fabricated modular units are quickly installed and secured to viaduct beams with steel cables, then disassembled and repurposed when needed. (2) User Access and Economic Model – Residents move in with periodic payments, and once they leave, the units are reassigned. (3) Adaptation and Evolution – The system continuously adjusts to new users and changing needs, allowing flexible reconfiguration of living spaces. This adaptable framework ensures that urban housing remains responsive, resilient, and accessible to those in need.

Migration, Urban Transformation, and the Nexus Model

Migration has long shaped societies, economies, and cities. Today, however, it is driven not only by economic opportunities but also by wars, human rights violations, climate change, and economic crises, forcing millions to leave their homes. These large-scale movements disrupt urban balance and place immense pressure on infrastructure. Modern migrants gravitate toward major cities for jobs, education, and healthcare, yet urban centers struggle to accommodate them. Housing shortages, rising rents, and overstretched infrastructure push low-income groups to the periphery, deepening social divides. Nexus offers a sustainable alternative by transforming underutilized urban spaces into housing solutions without straining existing infrastructure. Viaduct underpasses, often overlooked yet structurally robust, provide an ideal framework for modular, off-grid living. Suspended from viaduct beams with steel cables, Nexus's lightweight wooden modules create new living spaces, redefining urban resilience in response to migration-driven housing crises.

Research

01 / 04

Pixelated world map highlighting the countries people leave, in Latin America, Africa, the Middle East and Asia, with icons for inequality, war and economic causes. — 01Countries that experience out-migration, driven by inequality, war and economic conditions.

Pixelated world map highlighting the countries people move to, in North America, Europe, Russia and the Gulf, with icons for education, housing and economic reasons. — 02Countries that receive in-migration, for education, housing and economic opportunity.

Pixelated world map marking viaducts in receiving countries, including the Queen Street and S St viaducts, the A232, the Boulevard Périphérique, the Bispeengbuen viaduct, the E22, the D300 and the Wadi Laban Bridge. — 03Viaducts in receiving countries, potential sites for the modules.

Comparison sheet of six viaduct types, arch, truss, suspension, rigid frame, cable-stayed and girder, each with an elevation, a description and bars for cost, width, prevalence and strength, followed by sections of six girder viaduct types. — 04Viaduct types compared, with girder viaducts, the most common, broken down by section.

Section through a girder viaduct with timber housing modules hung beneath the deck on steel frames, showing piezoelectric modules in the road surface, cables and drainage running down to a battery and rainwater tank, a green wall filtering CO2 and dust, an expanded mesh walkway and people and trees below.

Strip of the UN Sustainable Development Goals icons followed by four panels explaining the piezoelectric energy harvesting system, rainwater harvesting and recycling, thermal comfort and the biohabitat green wall. — 01Section through the viaduct and its systems — piezoelectric energy from traffic, rainwater harvesting, thermal comfort and a biohabitat green wall — mapped to the UN Sustainable Development Goals.

The Module

01 / 03

Diagram of a grid of modules above nine house configurations, A to I, each combining five numbered squares for kitchen, living room, entrance, bedroom and bathroom in a different arrangement. — 01Nine house configurations, A to I, assembled from five room modules to suit each family.

Dimensioned plan of a 7.2 by 4.7 metre home of two timber modules either side of a central entrance, with the living room and kitchen on one side and the dining area and bathroom on the other, numbered 1 to 5. — 02Plan of a two-module home — kitchen, living room, entrance, bedroom and bathroom.

Dimensioned section through the timber module with people inside, annotated with the roof, wall and floor build-ups, from acoustic panels and roof panel systems to façade cassettes and insulated wall panels. — 03Section through the module, with the roof, wall and floor construction.

Assembly

01 / 05

Bill of materials with LVL timber, parquet, stainless steel box profiles, galvanised C profiles, Kingspan Karrier panels and steel-cored stranded rope, with sizes and quantities. — 01Materials, sized and counted for one home.

Axonometric of the fitted timber furniture, with wardrobes, shelving, a kitchen unit, a bench and a sofa. — 02Fitted furniture built into the modules.

Five-step axonometric of the modules being fabricated, loaded onto trucks, driven along the road and lifted by crane under the viaduct. — 03Delivery and installation — trucked in and craned under the viaduct.

Axonometric of the room modules strung along the cables, linked by red timber frames that form the connections between them. — 04Modules joined by timber frames along the suspension cables.

Exploded axonometric of a two-module home, from the floor and roof decks to the frame and the red façade panels with windows. — 05Exploded axonometric of a home and its red façade panels.

Visualisations

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View along a viaduct underpass at dusk, with red-clad housing modules hung beneath the deck on steel cables, a green wall, trees and planting below, and a couple walking arm in arm. — 01The modules suspended beneath the viaduct, above a planted public street.

Cutaway interior of a two-module home lined in pale timber, with a sofa and window on one side, built-in wardrobes around the entrance door, a woman opening a sliding partition and a man reading on a bed. — 02Inside a two-module home — living area, entrance and bedroom divided by sliding panels.

Timber-lined kitchen and sitting area with white cabinets, a woman preparing food, a white sofa with a cat beneath a square window, and a pendant lamp. — 03The kitchen and sitting area of a module.

Timber-lined living space with a framed screen on an easel, a woman by a sliding white wardrobe door, and a man pulling a fold-out bench from a built-in shelving and desk unit. — 04Built-in storage, desk and fold-out seating in the living module.