DGJ Architektur has completed Collegium Academicum IBA, a self-managed residence in Heidelberg, Germany, that combines affordable housing and communal living with educational and cultural uses. Initiated, developed, and implemented by a group of young activists, the project provides permanent living space for young people undertaking vocational training, studying, or completing a doctorate, alongside spaces for workshops, seminars, readings, and other events.
The building was conceived around self-administration, shared responsibility, and a sufficient approach to living. Residents live in shared flats for three or four people and take responsibility for tasks including rental management, maintenance, and financing. This organisational model forms part of the project’s educational programme, allowing residents to develop practical skills through everyday involvement in the running of the building.
Urban planning and architecture
Collegium Academicum has roots in a post-war student living and learning community founded in Heidelberg in 1945. The new building continues this legacy of communal education and self-governance through a contemporary model of affordable, self-managed housing.
Completed in spring 2023 as part of IBA Heidelberg, an International Building Exhibition focused on the city’s future urban development, the residence was built on the converted site of a former US military hospital in the Rohrbach district of Heidelberg. Designed by DGJ Architektur as a self- and community-governed student residence, the four-storey building provides 176 residential places in 46 units. Its two L-shaped timber structures form an entrance to the developing quarter and sit within an ensemble of old and new structures, contributing to the redevelopment of the wider site.
The two building volumes are arranged around an inner courtyard with a communal garden. Together with the roof terrace, the courtyard forms the social centre of the project, accommodating parties, leisure activities, sport, and informal encounters. The pergola, which provides barrier-free access to all apartments, is oriented towards this shared centre and widens on each floor to create smaller communal terraces.
The surrounding access system establishes visual connections between the flats and the courtyard, supporting a sense of shared life within the building. The facade was developed by DGJ Architektur as part of a research project by the German Federal Environmental Foundation, with movable sliding shutters that give the elevations a changing appearance.
The building structure also supports the project’s emphasis on project-based learning. A ground floor visible from the outside, together with the mix of living, leisure, and work areas, makes communal and educational activity part of the everyday presence of the building. A single-storey auditorium connects the two parts of the residence and provides a shared meeting place for occupants. Above it, a communal roof garden links the upper flats.
The outdoor areas are freely accessible and a cafe with a farm shop is planned for the former gatekeeper’s lodge. In the long term, the project is intended to contribute to a more networked neighbourhood in Rohrbach, where the wider district has been affected by an ageing population and limited infrastructure.
Self-managed living and education
Collegium Academicum began without a site or secured funding, but with the aim of creating a self-managed hall of residence for young people with an emphasis on sustainable and sufficient living. The project developed from this initial idea into a realised building and community-led organisation.
The residence also operates as an educational institution. Throughout the semester, it hosts interdisciplinary workshops, seminars, readings, and cultural events. One specific programme is the ‘falt*r’ orientation year, which offers young people a one-year interdisciplinary educational programme between school and their next stage of training or study. The programme is intended to give participants time and space for personal development and further education.
Participation and adaptable flats
Future residents were involved in the planning process through joint workshops with DGJ Architektur. The process went beyond consultation, with members of the project group making concrete decisions about the building and its use. Planning was developed through the construction of a demonstration room, with an example layout used to test the interior arrangement. During construction, volunteers from the project group and external participants were also involved through participatory construction sites and work camps.
The resulting housing model allows the flats to be adapted over time. Residents can reconfigure the relationship between individual and communal areas, negotiating spatial requirements and layouts while the building remains in use. The construction system allows residents to build and move interior walls themselves within a few hours. Partition walls and furniture for the flats can also be made in the in-house workshop.
Each flat consists of a central communal area, around which individual rooms and sanitary spaces are arranged. The individual rooms each consist of two 7-square-metre parts: a spatially enclosed core zone and an open zone that is initially connected to the communal area. Depending on residents’ needs and living habits, this flexible zone can remain open, be partially divided by furniture such as a table or shelf, or be spatially separated by moving the wall of the core zone or adding a second wall.
Timber construction and ‘Open Architecture’
The construction of Collegium Academicum is based on a timber hybrid system. The four-storey structure combines a load-bearing timber frame with stiffening wall panels around the sanitary cores and solid ceilings made from glue-laminated timber. Parts of the exterior walls and some internal partition walls also contribute to the stiffening of the structure.
The primary structure avoids metal fasteners, relying instead on form-fit and force-fit carpentry joints. The timber nodes reinterpret the Japanese Yatoi hozo sashi joint for contemporary production. This approach makes the building easier to dismantle than conventional construction. Prefabricated wall and ceiling elements were assembled on site, allowing for a short construction period.
The project uses the ‘Open Architecture’ construction system developed by Hans Drexler, founder of DGJ Architektur. The system is based on a flexible timber building approach that places users, their interactions, and their changing spatial needs at the centre of the design. It supports sustainable construction through the use of wood, as well as through the flexibility and adaptability it gives to residential buildings over time.
The building system is not treated as a fixed technical solution. Instead, it allows users to adapt the building during its operation, at different scales and at different points in its life cycle. This flexibility supports short-term changes within the flats while also allowing the building to respond to different forms of occupation over time.
The visible timber construction, the possibility of adapting space, and the proximity between shared flats all contribute to the character of the building. The architecture is shaped not only by its construction system, but also by the everyday participation of its residents.
Energy, materials, and certification
Collegium Academicum combines timber construction with strategies intended to reduce both embodied and operational emissions. DGJ describes the timber building as practically climate-neutral in its construction, with wood used as a renewable material that stores CO2. The building is also designed to have a high potential for recycling.
The building follows Passive House principles, with district heating used to meet the reduced heating demand. A photovoltaic system covers the flat roof on the fourth floor and is connected to battery storage and a surplus feed-in system, supporting the building’s operational energy strategy.
The courtyard-side access walkway serves as an escape and rescue route, requiring the adjoining facade to be non-combustible. An aluminium sheet facade was selected for this area, with a recycled raw material content of 90 percent. The facade can also be separated into its individual material components.
For the foundation, a base slab made of recycled concrete was constructed. The site was also filled with recycled material, most of which came from the building demolished on the conversion site. The new building is certified with the Sustainable Housing quality seal, NaWoh, in relation to its ecological footprint.
Long-term use and accessibility
Collegium Academicum was planned with future forms of occupation in mind. All flats are barrier-free and most are designed so that they could be used for senior-friendly living in the future. The flexibility of the four-person shared flats also allows other living arrangements, including larger shared flats or assisted living, to be created with limited intervention.
Through its adaptable layouts, self-managed structure, and timber construction system, the project connects everyday communal life with long-term spatial flexibility. Its architectural character comes from this combination: a building designed to be used, changed, maintained, and understood by the people who live in it.
