Feasibility Study: Reusing Vacancy – Hochbunker
client: Kulturdezernat Stadt Oberhausen (Creative City Oberhausen) / published by kitev – Kultur im Turm e.V.
size: 4000 sqm
type: feasibility study, adaptive reuse, participation
completion: April 2026
key words: bunker conversion, adaptive reuse, vacancy, participation, public roof, urban regeneration
role: project management and architectural coordination
A wartime bunker in the heart of Oberhausen: closed, massive and almost forgotten. The study asks what it would take to open it to the city.
A building made to keep the world out
Just one street away from Oberhausen’s main shopping street stands a wartime bunker. Its walls and roof were built to withstand bombs. Its few openings were made for air, not for light. For decades it has been used only as storage for local clubs, a dry and affordable place for things that have nowhere else to go. To everyone else it is a blank concrete block. The backyard behind it is full of garages and parked cars, rubbish piles up along the side entrances, and an old garden with mature trees lies hidden and unused.
Yet the bunker sits in one of the most diverse parts of the city centre. It is surrounded by schools, young people, older residents and families from many backgrounds, and there are very few public places to meet, play sports or spend time without spending money. The study set out to find out whether this closed building could become exactly such a place.
Listening before drawing
The process began with the people who know the bunker best. Interviews with the clubs that store their equipment there showed what the building means to them. They value it for being dry and affordable, and they are frustrated by the parking situation, the rubbish and the slow decay. A student spring school with participants from planning, architecture, social work, design and landscape ecology produced the first ideas: a colourful mix of uses across all floors, a hub for sport and wellness, and a green urban landscape around the bunker.
These ideas shaped the Week of Possibilities, three days in which the bunker opened its doors to the public. Guided tours led through rooms staged as possible futures:
a mushroom farm, inspired by Oberhausen’s post-war tradition of growing mushrooms in bunkers
a server room as a prompt to think about public digital infrastructure
a sound installation on rainwater, imagining the bunker as part of a “blue infrastructure” for the dense city centre
a rehearsal room for bands
a club for electronic music
Together with the city’s waste services, neighbours cleaned up the overgrown courtyard, which then became a stage for a choir concert, a band and an open jam session. Visitors wrote their wishes on an exhibition wall. The message was clear and shared by many: the bunker should not be demolished, but transformed, and it should be open to everyone.
Reading the city
Alongside the participation process, the study looked at the bunker in its wider context:
Social infrastructure: the eastern city centre has hardly any cultural or sociocultural places. Together with a nearby cinema, an educational centre and the Supermarkt der Ideen, the bunker could anchor a new cluster for culture and learning. Its closeness to schools and the lack of public sports spaces also make it a natural candidate for movement and play.
Climate: the surroundings are almost completely sealed and heat up strongly in summer. The flat roof and the backyard offer rare space for greenery, shade and rainwater retention.
Mobility: the bunker is easy to reach by public transport, but there is no clear, attractive route from the backyard to the shopping street. The building is hidden in plain sight.
Opening the block
The urban concept starts behind the bunker. The garages in the backyard are removed and parking is concentrated in a nearby car park that is hardly used. This frees the inner block. A new public path connects two streets, and a small square forms around the bunker. A hidden, half-private backyard becomes a visible piece of the city.
The bunker answers this opening. In every scenario its most visible corner turns into a café or restaurant, with the old garden as its outdoor extension. An external stair climbs the façade and leads up to the roof, which becomes a new public space above the rooftops. It can be planted as a green roof with solar panels, extended with an additional light-filled storey, or covered by a light open structure as a meeting point for young people.
Three futures
Three scenarios test how far the bunker can go:
Center for the Performing Arts: a cultural venue for contemporary and experimental performance, a type of place Oberhausen does not yet have. Rehearsal rooms, studios, workshops and exhibition spaces are stacked inside, connected by a ramp that winds through the floors. A filigree steel structure on the roof holds a public terrace with views across the city, and a new pavilion with a solar façade opens towards a sculpture garden.
Urban Fitness & Wellness Hub: free public sports areas on the lower floors are combined with commercial wellness further up, so that public benefit and economic stability support each other. A basketball court on the roof is reached by its own stair and stays open even when the building is closed. The garden becomes an outdoor gym, with a clear view from the café to the children playing outside.
Mushroom farm & capsule hotel: the darkness and constant climate inside the bunker become an advantage. Mushrooms grow in the windowless upper floors, and schools can come to learn about circular food production. A capsule hotel offers an unusual night in a historic building, lit from above through new skylights. The deep window reveals on the ground floor become seats, usable from inside and outside.
Precise interventions
Every new opening in the concrete is costly, so each one is placed where it brings the most light, air and connection. Existing shafts are reused for lifts wherever possible. Inside, the column structure allows the walls to be removed and the floors to be reorganised freely, and the structural analysis showed that the bunker has enough load reserves for almost any new use, including an additional storey. Fire safety was checked from the start.
All scenarios can be realised step by step: one floor, the roof or the garden first, with more to follow as demand grows. In all of them the bunker keeps what makes it unique: its mass, its raw concrete and its sense of enclosure. The bunker is not erased. It is reinterpreted, and a building made to keep the world out becomes a place that lets the city in.
Team: kitev – Robert Barbarino, Sonja Broy, Mustafa Sercan Bulut, Petra Jablonická, Yannis Kulosa, Christoph Kremerskothen, Meryem Yigit; Stefan Schroer, Christoph Stark, Agnieszka Wnuczak (strategic guidance)
Consultants: Rüdiger Ihle (structural engineering), Lorsbach + Buschmann (fire protection)
