The New Polykatoikia explores emerging models of collective housing, investigating how architecture redefines the ways we live together across diverse urban contexts and social ecosystems. Located in L’Hospitalet de Llobregat, within Barcelona’s metropolitan area, MARTÍ JULIA by m-i-r-a advances this inquiry through the comprehensive yet economical rehabilitation of a corner apartment building. Treating the existing structure as a resource for the future, the project resonates with the principles of the New European Bauhaus, demonstrating how adaptive reuse can cultivate a renewed urban identity for contemporary collective living through conceptual clarity, an expressive use of colour and meticulous attention to detail.
While Barcelona is internationally celebrated for its medieval quarters and the architectural legacy of Modernisme, neighbouring L’Hospitalet developed primarily during the second half of the twentieth century, absorbing successive waves of migration that produced a dense landscape of post-war housing estates and modest residential blocks. More recently, the municipality has become a laboratory for contemporary architecture, where works by architects such as David Chipperfield, Jean Nouvel and Richard Rogers coexist with the ordinary fabric of everyday domesticity. It is precisely within this layered urban condition—between anonymous housing and architectural ambition—that MARTI JULIA positions itself.
The intervention resonates with one of the most pressing architectural questions of our time: the reactivation of Europe’s existing building stock as perhaps its most valuable environmental resource.
Rather than pursuing tabula rasa, the project embraces the adaptive logic advocated by Lacaton, Vassal and Druot, for whom architectural value emerges through transformation rather than replacement and the existing building is understood as a repository of material, spatial and cultural memory.
Consequently, m-i-r-a’s architectural approach is founded on a deliberate dialogue between the existing structure and new interventions. Rather than concealing the building’s previous life, traces of demolition—including exposed concrete slabs, structural walls, and irregular surfaces—are selectively retained, allowing the construction’s material history to remain legible. These fragments coexist with precisely detailed contemporary additions, producing an architecture in which permanence and transformation are understood as complementary conditions.
As John Douglas argues, successful building adaptation lies not in restoring an imagined original condition but in allowing successive layers of occupation to become part of the architectural narrative.
This dialogue between permanence and change is reinforced through a rigorous chromatic strategy. An intense yellow extends across façades, balconies, shutters, railings, joinery and carefully selected interior details, transforming colour into an architectural infrastructure that establishes orientation, reinforces continuity between interior and exterior, and gives the building a distinct civic presence within the neighbourhood.
In doing so, MARTÍ JULIA reflects the ambitions of the New European Bauhaus, where aesthetic quality, environmental responsibility and the production of new forms of urban coexistence are conceived as mutually reinforcing dimensions of architectural practice.
Here, colour becomes a tool for strengthening collective identity, enhancing the experience of shared spaces and reaffirming the existing building as a recognisable urban landmark.
On the exterior, the intervention redefines the building’s presence through the repetition of yellow shutters and continuous balconies articulated by bespoke metal railings. Their subtle undulation tempers the orthogonal rigidity of the original structure, introducing a gentle rhythm that animates the façade while allowing colour and form to work in concert, redefining the building’s relationship with the street.
At roof level, a collective terrace extends the domestic realm into the open air.
Enclosed by a white parapet punctured with circular openings, the rooftop simultaneously frames fragments of the surrounding city while allowing light and air to permeate the space. The yellow interiors of these openings continue the chromatic narrative, producing moments of unexpected intensity that are perceived from both within and beyond the building.
Inside, the apartments are composed through a restrained yet tactile material palette. White walls, exposed concrete ceilings and timber flooring establish calm, durable interiors where everyday life unfolds without unnecessary excess. Kitchens are conceived as compact infrastructural cores, their precisely detailed joinery complemented by ceramic backsplashes in saturated yellows and deep greens that extend the project’s graphic vocabulary into the domestic scale.
Bathrooms are treated not as purely technical enclosures but as autonomous architectural rooms. Fully tiled in monochromatic colours, they combine circular mirrors, slender steel washbasins and walk-in showers to create spaces where utility and atmosphere coincide. The recurring circular motif subtly recalls the roof parapet, reinforcing a quiet formal continuity throughout the project.
Circulation becomes equally architectural. Rather than functioning merely as transitional elements, the staircases are conceived as spatial events that choreograph movement through the building.
Exposed concrete surfaces are paired with finely crafted yellow steel balustrades, producing a sculptural vertical sequence in which ascent becomes a perceptual experience. Echoing Bernard Tschumi’s understanding of architecture as the encounter between space, movement and event, the stairs become moments of architectural intensity in themselves.
MARTÍ JULIA affirms a growing architectural conviction: the future of housing depends less on building anew than on reimagining what already exists. By framing adaptive reuse as an aesthetically considered and economically viable approach to collective housing, the project demonstrates how heritage can become a resource for future development, revealing the transformation of Europe’s housing stock as one of the most compelling architectural challenges—and opportunities—of our time.
Drawings
Facts & Credits
Project title MARTÍ JULIA
Typology Adaptive Reuse, Apartment Building
Location L’Hospitalet de Llobregat, Barcelona, Catalonia, Spain
Area 800sq.m.
Status Completed, 2026
Architecture m-i-r-a
Collaborators Campana Arquitectos (structure)
Builders Henyo Estructuras – Sicetres
Photography Del Rio Bani
Bibliography
Douglas, J. (2006) Building Adaptation. 2nd edn. Oxford: Butterworth-Heinemann.
Druot, F., Lacaton, A. and Vassal, J.-P. (2007) Plus: Large Scale Housing Development – An Exceptional Case. Barcelona: Gustavo Gili.
European Commission (2021) New European Bauhaus: Beautiful, Sustainable, Together. Luxembourg: Publications Office of the European Union.
Tschumi, B. (1994) Architecture and Disjunction. Cambridge, MA: MIT Press.