Hollow: Co-Housing Architecture in Istanbul That Turns Historic Ruptures into Shared Urban Life

Hollow is a co-housing Hollow project in Istanbul that begins with an unusual architectural question: what happens when a historic wall is no longer understood only as an object of separation, but as a generator of collective space?

Developed by Mef University and Irem Metin, the project was recognized as a Shortlisted entry of Habitats ’20. Its proposal responds directly to the specific conditions of a site located near a historical wall, where continuity, rupture, enclosure, passage, neighborhood life, and urban memory overlap.

The project name, Hollow, emerges from this spatial condition. According to the design concept, the wall continues through the wider urban context as a seemingly coherent historical element. At the selected site, however, that continuity is interrupted. The break produces two gaps, or “hollows,” which become the conceptual foundation of the architecture.

Rather than repairing the rupture by reconstructing a continuous barrier, the project interprets the gaps as opportunities. These openings are transformed into public spaces for surrounding neighborhoods, while the co-housing building develops from the same spatial logic.

The result is a proposal in which co-housing architecture is not limited to the organization of private residential units around a shared room. Hollow expands the idea of collective living vertically, horizontally, and urbanistically. Circulation routes, terraces, courtyards, intermediate floors, stairs, openings, workshops, recreational spaces, and neighborhood connections become part of one continuous social framework.

A Site Strategy Built Around Continuity and Rupture

The project’s layout plan reveals a highly contextual approach. The building occupies a compact urban site among existing structures, streets, open areas, and the nearby historical condition identified in the drawings.

The site analysis does not treat the plot as an isolated parcel. Instead, the design reads the broader relationships between:

• the wall,
• the selected site,
• neighboring buildings,
• pedestrian movement,
• surrounding public space,
• landscape,
• and larger historical elements identified in the plan.

This approach is essential to the concept. Hollow is positioned where continuity has already been disrupted. The architecture does not attempt to conceal that fact. It works with it.

The gaps become spatial events.

One opening can be understood as a threshold between the neighborhood and the building. Another contributes to the formation of shared public territory. Together, they establish a sequence of arrival, movement, encounter, and occupation.

This makes the project particularly compelling as an example of co-housing architecture in a dense urban context. The design does not begin with an abstract residential block and then add communal facilities. It begins with an existing urban break and converts that break into an organizational principle.

From Historical Wall to Contemporary Social Infrastructure

The strongest conceptual move in Hollow is the reinterpretation of the wall.

Conventionally, a wall establishes an edge. It divides one condition from another. It protects, restricts, frames, or excludes. In Hollow, however, the wall’s logic is extended without simply reproducing its historical form.

The project continues that logic through a contemporary architectural system composed of layered edges, vertical screens, circulation bands, stairs, setbacks, and occupied thresholds.

This distinction matters.

Hollow does not appear to imitate the historic wall stylistically. Instead, based on the supplied drawings, it translates the idea of continuity into a new spatial language. The building envelope bends, rises, opens, and thickens. Its perimeter becomes inhabitable. Movement occurs along it. People pause beside it. Stairs connect different levels. Terraces extend collective activity upward.

The wall is therefore transformed from a static boundary into social infrastructure.

That reading aligns strongly with the broader architectural relevance of contemporary co-housing, where shared space and social relationships are central to the housing model rather than incidental additions. Co-housing literature and professional design research repeatedly frame collective facilities, adaptability, and community interaction as core spatial concerns.

The Hollow as Public Space

The two gaps are not residual spaces left behind by construction. They are the project’s primary civic gestures.

By allowing these voids to remain active and accessible, Hollow creates opportunities for neighborhood interaction. The architecture therefore operates across several scales at once:

the private scale of the resident,

the shared scale of the co-housing community,

and the public scale of the surrounding neighborhood.

This layered relationship is visible throughout the project drawings. People are shown entering from courtyard conditions, moving along exterior stairs, occupying terraces, sitting within intermediate spaces, gathering near open edges, and connecting between streets.

The project’s public dimension is especially clear in the visual studies labeled around themes such as:

• entrance from courtyard,
• hollow entrance,
• connection of the right side,
• wall to building,
• inside to the park,
• connection of streets,
• and street vista.

Together, these views demonstrate that access is not concentrated into a single conventional lobby. Arrival is distributed across a network of spatial relationships.

This is one of the project’s most significant contributions to co-housing architecture. Collective life begins before a resident reaches the front door.

A Vertical Network of Everyday Encounters

One of the most expressive images in the project maps social activity across the building through fragments of conversation and daily interaction.

People meet on stairs.

Residents notice views.

Neighbors talk across intermediate spaces.

Someone hears music.

Others attend workshops.

Children and adults move through the building.

A dog appears within the shared environment.

A piano occupies a communal area.

Terraces become places for conversation.

Exhibition spaces attract visitors.

The drawing is less concerned with presenting architecture as a silent object and more interested in showing architecture as a field of relationships.

This is a crucial distinction. The building is represented as inhabited throughout its height. Social activity is not confined to a ground-floor common room. Instead, the entire section becomes active.

Balconies, bridges, staircases, landings, rooms, courtyards, and terraces operate as interconnected social stages.

The black graphic line that moves across the axonometric image reinforces this interpretation. It visually traces a continuous, irregular route around the building, suggesting that collective experience is assembled from many small moments rather than one monumental communal space.

Co-Housing Architecture Designed Around Daily Life

The project’s daily routine diagram provides another important insight into the design philosophy.

Rather than describing the building only through room labels, the proposal maps time. A sequence from morning to late evening includes activities such as:

• waking up,
• cleaning,
• drinking coffee,
• having breakfast,
• working,
• spending time in the courtyard,
• family time,
• resting,
• workshops,
• taking group photographs,
• listening to music,
• dinner,
• meeting neighbors,
• terrace gatherings,
• and sleeping.

The importance of this diagram lies in its portrayal of housing as a temporal system.

A home changes throughout the day. Spaces that are quiet in the morning can become social in the afternoon. A terrace can serve one person at one hour and a larger group later. Courtyards can support both everyday routine and spontaneous interaction.

Hollow embraces that variability.

Its architecture appears designed around the accumulation of ordinary events. This gives the co-housing model a human scale. Community is not represented as a forced program. It emerges through repeated opportunities to meet, observe, participate, rest, and move.

Flexible Interiors for Shared Occupation

The supplied interior visualization reinforces the project’s emphasis on adaptable collective space.

A large room is shown supporting multiple users and activities. A table tennis setup introduces recreation. Different generations occupy the room. A dog moves through the shared environment. Large openings connect the interior with views toward the surrounding context.

The architecture itself remains visually restrained.

Light surfaces, exposed structural logic, modular ceiling panels, large framed openings, and flexible wall elements create a neutral background for occupation. A stronger coral-toned surface introduces identity without dominating the space.

Most importantly, the interior is shown as active rather than fixed.

The large openings and operable elements suggest that boundaries can change according to use. The room can become more open, more enclosed, more connected to circulation, or more responsive to different forms of communal activity.

This flexibility supports the central ambition of the project: collective housing should accommodate changing patterns of daily life rather than forcing residents into a rigid program.

Circulation as Social Space

In many residential buildings, circulation is treated as leftover space.

Corridors move people from lifts to apartments. Stairs satisfy functional or regulatory requirements. Landings remain empty.

Hollow challenges that condition.

The project’s perspectives suggest that stairs and circulation routes are among its most socially important architectural elements. Exterior and semi-exterior stairways wrap around parts of the building. Platforms widen into places of pause. Connections between levels are visible. Movement is exposed rather than hidden.

This transforms circulation into a form of collective infrastructure.

Residents do not simply travel through the building. They see one another while moving. They encounter activity on adjacent levels. They observe public spaces below. They connect with terraces above.

Such visibility can support a sense of shared presence without requiring constant direct interaction.

That balance is critical in co-housing. Collective living cannot depend on eliminating privacy. Instead, architecture can create different degrees of participation. A resident may join a gathering, watch from a balcony, pass through a shared stair, sit at an edge, or retreat into a more private zone.

Hollow’s sectional complexity gives architectural form to these different levels of engagement.

A Section That Organizes Community Vertically

The section perspective is one of the clearest representations of the project’s spatial ambition.

The building rises through multiple levels while also extending below ground. Shared activity appears at different elevations. Stairs connect floors externally and internally. Open terraces interrupt the mass. Voids allow visual relationships across levels.

The building is therefore not conceived as a stack of identical residential slabs.

Instead, it operates as a vertically connected environment.

Based on the technical annotations in the supplied drawing, the project combines a steel load-bearing system, reinforced concrete construction, and a raft foundation. These systems are shown as part of a broader sectional strategy extending across upper and lower levels.

The structural information gives the speculative social concept a degree of tectonic clarity. The project attempts to connect its communal ambitions with an identifiable construction logic rather than presenting the proposal solely as an abstract diagram.

The Facade as an Inhabited Edge

Hollow’s envelope is another important feature of the project.

The external appearance is defined by repeated vertical elements that create a layered, permeable surface. Rather than producing a sealed facade, this system mediates between the residents and the city.

Behind and around the screen, people occupy balconies, stairs, terraces, and intermediate spaces.

The facade therefore changes according to movement.

From one viewpoint, it reads as a continuous vertical field.

From another, it opens to reveal circulation.

At corners, it bends.

At terraces, it recedes.

At gaps, it exposes the depth of the building.

This layered treatment supports the project’s central wall concept. The envelope retains a sense of continuity while allowing interruptions and occupation. It is simultaneously boundary, screen, circulation edge, and collective interface.

Connecting Courtyard, Park, Street, and Neighborhood

The project’s exterior perspectives show a deliberate effort to make the building part of a larger network of movement.

One view focuses on an entrance from the courtyard.

Another examines the hollow itself as an entrance condition.

Additional images explore the connection between different sides of the site, movement toward the park, and relationships between streets.

These studies indicate that Hollow is not intended to function as an inward-looking residential enclave.

Instead, it attempts to create permeability.

The building becomes a connector between existing urban conditions. Its architecture draws people through gaps, along edges, up stairs, and across intermediate territories.

This gives the project a broader urban role. The shared spaces are not understood only as amenities for residents. Some become points of exchange with the neighborhood.

Architecture as a Framework for Social Choice

Perhaps the most compelling aspect of Hollow is that it represents community through multiple forms of occupation.

The drawings show workshops, exhibitions, conversations, family time, music, recreation, pets, meals, work, rest, and spontaneous observation.

There is no single definition of collective living.

That is a strength.

The project acknowledges that people experience community differently. One resident may participate in a workshop. Another may sit alone on a stair. Someone may meet neighbors over dinner. Another person may simply enjoy seeing activity from a terrace.

Architecture becomes a framework for choice.

This is more convincing than treating co-housing as a formula in which residents are expected to socialize continuously. Hollow instead creates a gradient between public, collective, semi-private, and private conditions.

The result is a richer interpretation of shared habitat.

Historic Context Without Literal Imitation

Hollow’s relationship with the historical wall is conceptual rather than decorative.

The project does not rely on superficial references to historical architectural style. It does not appear to reproduce old masonry forms or simulate an image of the past.

Instead, it asks what the wall does spatially.

It continues.

It breaks.

It separates.

It defines edges.

It creates sides.

It produces gaps.

It influences movement.

Hollow takes those operations and transforms them into contemporary housing strategies.

This allows the project to respond to historical context without becoming visually dependent on imitation. The past becomes a spatial intelligence that informs new architecture.

Why Hollow Matters as a Co-Housing Architecture Proposal

Hollow stands out because it combines three scales of architectural thinking.

At the urban scale, it interprets rupture in the wall and uses the gaps to create public space.

At the building scale, it develops a vertically interconnected system of terraces, stairs, screens, voids, and shared zones.

At the human scale, it maps ordinary routines, conversations, meals, work, recreation, rest, and neighborhood encounters.

These scales reinforce one another.

The wall informs the building.

The building organizes movement.

Movement produces encounters.

Encounters support collective life.

This chain of relationships gives the project conceptual coherence.

A Shortlisted Habitats ’20 Vision for Collective Urban Living

As a Shortlisted entry of Habitats ’20, Hollow presents a distinctive vision of communal housing in Istanbul.

The project by Mef University and Irem Metin does more than place residents within a shared building. It investigates how a co-housing project can emerge from a specific urban condition, inherit the logic of a historical boundary, and transform breaks in that boundary into active neighborhood spaces.

Its architecture is shaped by gaps rather than completeness.

By circulation rather than static corridors.

By terraces rather than sealed facades.

By daily routines rather than abstract program alone.

By connections rather than isolation.

Through this approach, Hollow proposes a form of co-housing architecture in which the edge between building and city becomes productive. The historical wall is not simply an object to observe from a distance. Its logic becomes the starting point for a new collective habitat.

The “hollow” is therefore not an absence.

It is where the project begins.

It is the space where continuity opens.

Where neighborhoods enter.

Where residents meet.

Where circulation becomes social.

And where architecture turns a rupture in the city into a framework for shared urban life.