RENOVATION AND EXTENSION OF MEERESMUSEUM
A BREATH OF FRESH AIR WITHIN ANCIENT WALLS
Renovation and expansion in a historical context
The German Oceanographic Museum in Stralsund is an institution with charisma. It has shaped the city’s identity, grown over decades, and become firmly anchored in the collective memory. It is one of the most visited museums in Germany and enjoys an excellent reputation and high standing internationally as an oceanographic institution. Under the umbrella brand of the German Oceanographic Museum, it combines four locations: the main building in the historic Katharinenkloster, the Natureum in the lighthouse at Darßer Ort, the Nautineum as an open-air museum, and the Ozeaneum on the harbour island, which was named European Museum of the Year in 2010.
In 2017, an international architectural competition was launched, which was won by Reichel Schlaier Architects from Stuttgart. The aim was to develop the main building of the MEERESMUSEUM in Katharinenkloster into a contemporary museum in terms of both structure and function.
The challenge was to integrate parts of the building and historical layers from different centuries and generations. Sensitive handling of the building fabric was essential, as the ensemble is one of the most important urban structures in the Hanseatic city of Stralsund and part of the UNESCO World Heritage Site. The jury particularly praised the concept of preserving, highlighting, and revitalising the main attractions of the MEERESMUSEUM, which has grown over decades.
One of the greatest architectural challenges was to create a harmonious connection—from the initial design phase through to the choice of materials and detailing—between the historic monastery complex, the later additions, and the newly inserted elements: an architecture that respectfully honours the old while coherently complementing it with the new.
Exposure of the existing structure
The gothic complex of a former Dominican monastery from the early 14th century was continuously altered and expanded for various uses throughout its eventful history. After the Reformation, it served as a school, arsenal, and orphanage, among other uses, before the MEERESMUSEUM and the Stralsund Museum moved in during the 20th century. Further structural additions from various eras and the functional division of the complex into two different museums made it difficult to experience the monastery, which was largely preserved in its substance, as a coherent whole. A simple solution to clarify the structural situation would have been to dismantle all the added elements to make the historic complex visible again. However, additions were still necessary for its use as a MEERESMUSEUM. Some later interventions—such as the special truss structure from the GDR era in the nave—were also of historical and cultural value and therefore had to be preserved as monuments. A differentiated approach was therefore chosen: the aim was to integrate the new uses in respectful harmony with the valuable historical substance and, at the same time, to reveal the original core of the monastery complex.
To this effect, all structural additions were examined in terms of their cultural and historical value. Structures of minor importance were removed or gutted, allowing the historic façade facing the city wall to be re-exposed through these measures. The structure of the monastery complex with its original spatial relationships became visible once again. For example, the demolition of a partition wall to the Stralsund Museum revealed the “Long Corridor” that once connected the historic cloisters with the city wall. The historic Westhof was also opened and made accessible to visitors. The opening of the choir floor revealed the foundations of a previous church, and medieval cellars were discovered under the new forum.
Architecture between the ages
After the careful dismantling of a few individual elements, the task was to architecturally redesign the gothic monastery complex with its additions from the 19th century and the 1950s, 1970s, and 1990s. The aim was to preserve as much of the building fabric as possible and only intervene where necessary for functional reasons. The task was therefore not to restore the building to its historical form with careful minor additions. Rather, it was to formulate an answer to the question of how old and new can be brought together and, above all, how each layer of time can remain visible and yet fit into the whole.
Due to the integrity, great age, and special value of the gothic architecture, it was inconceivable for the architects to continue building in that same style, especially since the modern structural interventions of the last 50 years already have their own monument value. The clear legibility of old and new in the sense of the Venice Charter therefore presented itself as the only viable approach. Each era remains recognisable and at the same time fits into a continuum of architectural history that shapes the identity of the entire complex.
All additions and newer extensions to the existing building were given a uniform external appearance. This is reflected in their material and structure when viewed up close, and in their simpler, more abstract volumetry when viewed from a distance. Thanks to its location on the city wall, the ensemble is also clearly visible from afar. A copper sheet cladding—a familiar material in Stralsund, reminiscent of the roofs of historic brick churches—gives the new structure a striking yet understated appearance. The handcrafted batten seam, a special type of copper sheet installation, emphasises the structure of the surface and references the rhythm of the neighbouring Gothic architecture.
Glazed elements connect the enclosed volumes of the extensions with the historic building. They continue the rhythm of the copper façades and at the same time provide specific views of the Gothic architecture—for example, at the glass joint between the new roof of Westhof and Katharinenhalle, which allows a view of the gable and of the nave in its full height.
New paths through the museum
The gradual expansion of the MEERESMUSEUM over decades not only contributed to the heterogeneity of the complex described above. It also resulted in a route that led visitors through the complex on winding paths across different levels. The task of creating an overview and orientation was therefore not easy to solve. For this reason, the competition brief suggested new structural elements and the conversion of further parts of the building. The somewhat abrupt side entrance to the nave as the main entrance to the museum also had to be reconsidered.
The former forum in the north courtyard, originally built as a sports hall in the 19th century and most recently used as a conference and temporary exhibition space, now serves as the new main entrance to the museum. The ticket offices and central information desk are now located here. From here, visitors can access the monastery’s historic Westhof, which, with its light building envelope, has been transformed into a central meeting place with seating and a museum shop.
By relocating the entrance and routing visitors through Westhof, the exhibition in Katharinenhalle can now be accessed via the historic portal of the nave. Generous ceiling openings and a revised route make it easier to find your way around Katharinenhalle; the sacred space from the monastery’s founding period can now be experienced in its entirety.
Of course, the special bar structure from the GDR era in the nave—itself of contemporary historical and cultural value and listed as a historical monument—has been preserved and carefully adapted. A new, multi-storey structure with a large aquarium connects the exhibition levels vertically with further aquariums in the basement. The tour ends at the Turtle Aquarium and leads back to the starting point in Westhof via the “Long Corridor”.
Accessibility for all guests and visitors was a particular challenge when planning the new route. The historic parts of the building and their extensions have different height levels on the various floors. Sloping floors in Westhof and Haselbergbau made it possible to significantly reduce the number of elevators. The path through the “Long Corridor” leads over a footbridge above this significantly lower original floor level. The lightweight steel structure is detached from the walls of the corridor, preserving the historic proportions of the room.
New exhibition – established and modern elements
The new exhibition was designed and realised by the Munich-based firm Die Werft in collaboration with the exhibition organisers at the German MEERESMUSEUM. Great emphasis was placed on ensuring that popular exhibits would still be on display after the renovation and would be supplemented by high-quality new objects. On three exhibition levels in Katharinenhalle and the adjacent Haselbergbau, four thematic areas present the evolution of life from the sea, the interactions between humans and the sea, the diversity of marine habitats, and strategies for sustainable fishing.
Concept of sustainable construction in historic buildings
The respectful treatment of the existing structure not only served to protect the historic building fabric but was also an integral part of a comprehensive sustainability concept. The aim was to renovate the existing building with as little grey energy as possible. As a result, apart from the extension of the large aquarium, which was necessary for the routing and reattraction, very little new building fabric was added. All new building envelopes not connected to water or soil were constructed from wood.
Dismantled materials were reused wherever possible. The flooring in Westhof consists of historic granite stones that the museum had stored for years. Masonry work was carried out using existing bricks. Old fire protection glazing was removed, secured, and reused elsewhere. The existing cloakroom lockers were refurbished and reused in the new cloakroom area. In all areas of planning, careful consideration was given to whether existing features could be retained or reused elsewhere.
For example, all existing windows were retained, and the railings were only replaced where necessary under building regulations. Removed wood was refurbished and reused, for example, as stair treads or benches. The paving in Katharinenhalle was retained in its entirety. The north courtyard with its old paving, trees, museum ship, and other features remained largely unchanged. The existing steps in front of the forum were widened to provide barrier-free access to the new main entrance.
By retaining the existing ground levels, the former striking entrance to Katharinenhalle with its archway remains fully visible.
Energy concept
The technical equipment also followed the maxim of reusing existing materials and reducing technology to the essentials. Functioning components from the old building were retained. Active ventilation was largely dispensed with, and existing radiators and pipes were retained. At the same time, energy efficiency was significantly increased: heating systems were replaced, and highly efficient air-to-water heat pumps with heat recovery and rotary heat exchangers enable up to 80% energy recovery. New parts of the building were fitted with underfloor heating and ventilation systems.
Operating the aquarium is particularly energy intensive. State-of-the-art direct current and three-phase pumps were used, which almost halve the energy requirement. Existing reservoirs, skimmers, and pipes could also be reused. To further reduce the overall energy requirement, not only the object and exhibition lighting but also the entire aquarium lighting was converted to LED technology.
Archaeology
The construction project was accompanied by archaeological work and yielded numerous finds. In the choir of Katharinenhalle, the foundations of a chapel built before 1282 were uncovered—the oldest known church in the Hanseatic city to date. Medieval cellars were uncovered beneath the forum and integrated into the new building.
In addition, archaeologists discovered around a hundred skeletons of people who died in a powder explosion about 250 years ago. These and other finds are displayed and explained to museum visitors in several locations within the new ensemble.
