Leitz has long been a family business with an important history for the region and Germany. Intelligent innovations in the product range and production methods have guaranteed the company a secure position in the market for generations. Entrepreneurial wisdom and technical experimentation have also had a recognizable influence on the development of the buildings on the Leitz site in every phase of the company's development: demand-oriented construction, establishing the idea of the “multi-storey factory” as the maximum flexible building form for adapting to changing production requirements or working conditions, careful handling of the public outdoor spaces through contemporary façade solutions, etc. “Keeping things in proportion” was the motif - today we call it “sustainability”.
"THE NEW LEITZ" - International Green Startup Campus
In the future, “resources” will be thought of, developed and produced here in an overarching, networked way. By “resource” we mean cultural and social resources as well as individual or communal, technical and artistic, material, (production) processes, e.g. recycling. Lateral thinking is desired, networked thinking across borders is the goal: “International Green Startup Campus”, an accelerator that consciously seeks proximity to local companies and universities.
We want to create an inspiring place that brings people together to think about contemporary issues in a cross-cultural, multi-professional way. It is an educational project, a project for development, a project for production - a cluster in the best sense of the word.
To achieve this goal, we want to change the atmosphere in the area. People must be able to work and - temporarily - live here. We are removing buildings that are not protected and adding another building to the still rudimentary ensemble of buildings along Sieglestrasse, the future “Leitz Boulevard” (Area Management City of Stuttgart). This will create public and semi-public spaces for people who work or live here. It will be quiet, the surfaces will be unsealed and the uses will be mixed.
The “Mühlengrund” in Neu-Hohenschönhausen is a popular and still affordable residential area surrounded by large-scale urban structures on the northern outskirts of Berlin. In recent years, however, infrastructural deficits have become increasingly apparent here. There was no “neighborhood center” and there is a shortage of doctors. In order to meet the growing demand for housing in Berlin and the needs of residents who have lived here for a long time, the plots of a former department store and two unprofitable new buildings from the 1990s were released for demolition a few years ago. The convenient transport connections with a streetcar stop, a beautiful stock of trees and an existing neighborhood square with a remarkable fountain sculpture provided the backdrop for a neighborhood development with three buildings around this lively outdoor space.
Building
The open floor plans of the houses are filled with a variety of different types of apartments - apartments with outside access through a private garden, single apartments and multi-storey apartments with different numbers of rooms through to open-plan apartments for five or more people. The inner courtyards are private, reserved for the building community and their guests - with children's playgrounds, trees and benches for spending time together. The access systems are developed in a differentiated manner depending on the orientation of the building, use of the ground floor and optimized escape routes. The roof areas are extensively greened or covered with PV systems for tenant electricity. Stationary traffic is organized in the basement levels of buildings 1 and 3, as are a relevant proportion of the bicycle parking spaces, the building services and storage rooms for rental units.
Construction
The three buildings of different heights and storeys - VI - VIII - were developed as 3 free-standing volumes in timber-concrete hybrid construction: The supporting structure of each building forms a simple skeleton of reinforced concrete columns with semi-precast flat slabs. This creates a “plan libre”, a free floor plan with options for different uses and layouts: Retail and other businesses on the ground floor, the health center and offices on the first floor as a “service horizon”, then the residential floors above with a diverse mix of apartments.
Facade
The building envelope is formed by curtain-type, storey-high wall elements in timber frame construction. The elements were completely pre-assembled at the factory, insulated and clad with rear-ventilated timber or metal façades. The material of the outer skin changes from house to house or, in some cases, from building side to building side. This creates an exciting interplay of pre-greyed timber and white trapezoidal sheet metal facades. The steel balconies, which are also completely prefabricated, puncture the timber façades in a seemingly random rhythm. Together with the free interplay of the differently sized windows, this creates an exciting façade image.
RWI 4 was originally built in 1974 as a bank building and formally corresponds to the representative requirements of companies in the financial and insurance sector at the time. Today, the company no longer exists.
Two twelve-storey office towers currently stand on a two-storey base structure on the extensive site. Underneath, 501 parking spaces are organized on two underground parking levels, which are accessed via an expansive access spindle. We are proposing structural additions to this existing building consisting of two structures: the “Loretto Terraces” on Neusser Strasse and the “LorettoLoretto” in the central location. The three new buildings are intended for residential use with different residential typologies. A total of around 90 apartments are to be built.
House A
House A with maisonettes is planned parallel to Duisburger Strasse. The entrances to the maisonettes on the first floor are provided on the south side and are accessed via small private front gardens. Two vertical accesses break through the façade on the long sides and provide access to the upper maisonettes via an arcade on the south side. The roof gardens are accessible from the respective residential units via a staircase.
House B und C
House B and House C contain multi-storey apartments. The entrance to the underground parking garage and a stairwell for vertical access to the apartments are located on the north side of building B. A second vertical access route, including an elevator, is located on the south side of the building outside the building cubature. The first floor apartments each have a small private garden area and the apartments on the upper floors have balconies in front of them.
In the long block along the harbor railroad of House C, there are interspersed apartments of different sizes. An arcade on the north side provides access to all floors. On the south side, the apartments will have balconies in front of them. The arcades of the two buildings B and C are connected on all upper floors by walkways, which extend to the west and east on the 2nd and 3rd floors and generate additional communal areas for the residents.
The Hafen und Hof GmbH & Co. KG has a large number of different users. In addition to various bus operators, there is also a marina with boat rental operators and a restaurant on the site. In order to expand the offer on the site and meet demand, a new building block is being planned in this ensemble.
In the future, the new “Hafenhaus” building will provide additional gastronomic offerings, space for boarding house use, office space and space for port operations. The aim is to upgrade the location as a whole and meet the needs of current users for more space. Large parts of the first floor are planned as an air floor. This is to ensure that bus operations can continue on the site without restriction.
On the upper floors, 19 units are planned as a boarding house in various sizes. The boarding house is an accommodation facility designed for guests with longer stays. The units facing the waterfront are a special feature. A new gastronomic concept is planned for the first and second floors. The space, which is open across both floors, is to be operated as an exclusive restaurant in a living room-like atmosphere in future.
The top floor is planned as a restaurant and event space. Especially at weekends, when the bus service on the site is largely at a standstill, many Berliners already make use of the gastronomic offerings on the site. The roof terrace is intended to expand this offer both in terms of space and content. In addition to the restaurant, a pool is also planned on the roof.
The building will be constructed as a reinforced concrete skeleton structure. Only the core on the north-western side of the building will be solid. Lightweight partition walls will be made of drywall.
A comprehensive redesign of the water's edge is planned to positively influence the atmosphere on the property. The site has already been developed and the new building will be connected to the existing infrastructure.
Heat will be provided by a combined heat and power plant. In future, this will not only supply the new building, but also the existing “Hafenküche” restaurant.
The interaction of working and living promotes vitality in every city center.
Life has shifted to the outskirts of cities, where, in contrast to the city center, generous green spaces are available nearby and the workplace is also easily accessible by car. As a result, the inner cities lost a large proportion of their inhabitants and were filled with work and retail space. Living and working were separated.
The digitalization of workplaces is breaking down this traditional structure. People can work from anywhere, making the traditional office building less important. Working environments are becoming more flexible and location-independent, but at the same time require an attractive range of leisure activities. New mobility concepts are increasingly making it possible to do without investing in a private car.
The conversion of the former RAG high-rise building into a residential building addresses these changes, which affect both cities and their citizens, by finding a solution for both.
A. Location
The building is in a privileged location in the heart of the city. Situated next to the opera house, it has its main entrance on the north-south axis of Hansastrasse. The extensive retail areas, the varied gastronomy and various leisure facilities can be reached on foot in a very short time. The location is very well connected thanks to its proximity to public transport, the subway and the main railway station. Users with their own vehicle can use the existing garage with 121 parking spaces.
B. Concept: a place to live and experience
The building rises like a pyramid. The existing building has structures with deep areas on the first floor and second floor, which are still suitable for commercial use with internal service cores. Our concept retains the commercial use of the first two floors - ideally, the current co-working spaces can continue to be offered - and begins with the conversion to residential space on the second floor. The new residential units are located along the existing corridors, and the flexibility of the office layout is reflected in the new apartment layout, which allows for a range of different sizes and unit types. Loggias or balconies are provided in the apartment layouts to give each resident private access to the outdoors. The roof spaces created by the staggering of the building volume on every other floor are transformed into gardens for the community of residents, which also allow for a concept of curated urban gardening. The building offers interesting views in every direction. The RAG building is no longer just a place to work, but rather a place to live and experience. The reuse of the existing building fabric, the reduction of the ecological footprint by bringing residents back into the heart of the city, the sustainable and social way of life through generous shared green spaces all fit into the current context.
A new use requires a new identity. The RAG building has very formal features with a strong presence - the regular grid of the metal panels with the horizontal bands in front contrasts with the strongly pronounced volume development of the complex.
C. Facade concept
Retention of the existing façade with integration of greenery: the curtain wall with its typical glass elements will be retained. Only the windows will be replaced to allow natural ventilation of the apartments. Individual floor-to-ceiling openings will be created that open up like a “French balcony” to the cleaning corridor and offer the residents a perceived outdoor space. This itself will be planted with climbing plants. In this way, the RAG building is covered with green strips like a tree, making the outer shell appear different depending on the season.
The competition site on Wellinghofer Strasse offers excellent potential for a housing project with apartments, especially for families with children - embedded in a green corridor with a wide view of Phoenix West, a school and a potentially good position for gardens with a south/west orientation. Unfortunately, the provisions of the legally binding development plan are far removed from the requirements of the current Climate Protection Act. For example, a large number of existing trees are to be disposed of, a high demand for car parking spaces is defined, which cannot be met in a basement garage alone and therefore requires additional sealed areas above ground. The idea of a “sponge city” is thus thwarted. The planned north/south orientation of a large part of the future development does not allow for well-lit apartments with maximum use of the buildable area - building depth 18m.
We have therefore decided to deviate from some of the stipulations in order to create a balanced relationship between private and semi-public spaces and to create favorable conditions for climate-friendly and resource-conscious construction.
Living with nature
Children play in the fresh air, splash around in the natural pond, neighbors with green fingers garden in the vegetable patch and the fire pit is the place for spontaneous or planned celebrations. The existing green corridor is to be visually transferred to the private gardens and semi-public open spaces of the building community. In this way, we want to ensure ecological diversity and the infiltration capacity of the soil as far as possible. The underground car park will be enclosed with small walls, steps and seating, staggered paths, planting beds and water basins or infiltration troughs. The artificial geometry of the garden is a basic pattern that runs through the entire quarter and deliberately contrasts with the natural wildflower meadow, flowering fruit trees and native shrubs and hedges. Drought-resistant plants and moisture-retaining ground covers are preferred when selecting plants.
Access + Apartements
All building entrances and the entrance/exit to the underground parking garage are addressed to Planstrasse. The entrances are barrier-free and wheelchair-accessible. Arcades are designed so that they can be meeting points for informal exchanges. Each apartment is oriented on two or three sides and is therefore very well lit and ventilated. In construction site 2, we are currently planning large first floor apartments that are accessed via an inner courtyard and private front gardens. The specific staggering of the volumes allows for a roof terrace on each building for use by the building community.
Concept Floorplan
The floor plan concept contains only a few fixed components (shafts, columns or walls). The type of construction allows for a high degree of floor plan variability within the supporting structure and thus enables different layouts - apartments from 25 m2 to 250 m2 - from one-room apartments to cluster apartments for shared flats or integrated “townhouses” with individual entrances and private gardens for families. This means that a large number of small and medium-sized apartments can be created, as well as a smaller number of larger apartments. In this layout, we are proposing approx. 83 units on a gross floor area of approx. 9,200 m2, mainly apartments for families with children in various apartment typologies.
Building Equipment
The energy requirement is covered without complex building technology, via district heating. To this end, the new residential quarter in Planstrasse will be connected to the city of Dortmund's new low-CO2 local heating network. The building envelope (Efficiency House 40) of the houses in conjunction with low-temperature underfloor heating and façade-integrated decentralized ventilation units with highly effective heat recovery reduce the primary energy requirement. Shafts are bundled as far as possible and their number is reduced to a minimum, with external awnings (south-facing windows) or curtains on the balconies, depending on the orientation. Generous window areas with triple glazing allow - if necessary - a high natural heat input into the apartments in winter. PV systems (CIS solar modules) will be installed on the roofs to generate electricity (60% of the gross roof area). The yield and consumption data will be available to all residents on a touch panel in their apartments. The aim is to motivate them to use energy sparingly.
Construction + Architecture
Hybrids are created from timber (exterior walls, interior walls, columns) and prestressed reinforced concrete hollow core slabs (ceilings) with a high degree of prefabrication and great detail quality as a “detachable” construction - designed in such a way that they can be separated by type and treated separately - for reuse or disposal. StBn is used where sound and fire protection requirements make other constructions uneconomical - in the garage as a monolithic StBn construction, in the rising storeys with prestressed concrete hollow planks, which are characterized by a minimized use of materials: -50% concrete and -70% steel. Wooden walls and columns (west side) form the primary supporting structure with a grid of 7.5 m on which the prestressed concrete hollow core slabs are placed. Cores for TH and elevators form part of the bracing. Closed wall panels also have a stiffening effect on the structure. The exterior walls are brought to the construction site as a timber frame construction with a pre-greyed timber cladding and assembled to the supporting structure there. The principle of “no waste” should be adhered to during production and erection on site.
The era of inner-city shopping malls and shopping streets is coming to an end. New forms of retail and digital payment methods are making old-style shopping malls obsolete. This creates the opportunity to rediscover the city as a living space and give it back to the people. However, it is by no means possible to simply replace retail with housing.
Urbanity is created through plurality
This includes mixed uses as well as different residential typologies that promote real neighborhoods and generate identification potential for one's own “Kiez”. Sustainability, the lowest possible energy requirements, resource awareness from the limited building site to the selected building materials, mobility, etc. are self-evident aspects of the planning. However, the essential characteristic should be the creation of new places where people like to live.
A - Access
A group of buildings of different types with differentiated heights forms a new neighborhood. It is linked by public paths, alleyways and small squares - for access to the buildings, small-scale retail, eating and drinking or simply for spending time. The quarter is integrated into the overarching network of routes in the city center between the main train station, Westenhellweg and Marktplatz or Hansaplatz.
B - Mixed Use
The use of the buildings and floors will be mixed. Small, adaptable stores, cafés and restaurants will be created on the first floors, which can be extended to the first floor if required. Commercial uses will also dominate the first floor - offices, doctors and the like. The basement brings the buildings together under one floor and forms a continuous storey for parking spaces, technical rooms and other ancillary areas.
C - Sustainability
The use of materials, an efficient energy concept, short distances, the multi-layered linking of individual private and public mobility, social and cultural acceptance and other sustainability aspects are developed from the outset in a multi-professional team and brought together in an overall concept. A key starting point for us is the conceptual integration of an accessible green backdrop. As a structural break, it separates the floors with commercial use from those with residential use. It runs through the buildings, the courtyards, becomes denser at selected edges, recesses or terraces and gathers as a roof garden with bridges connecting all the buildings - a multi-storey park designed for the residents of these buildings.
D - Mobility
The group of buildings on Amiens Square is located in the immediate vicinity of Dortmund's main railway station with a variety of regional and national connections as well as direct access to inner-city public transport with buses and the S-Bahn. We will combine these options with a concept that ensures individual mobility - through an internal sharing system for e-bikes and cars that are available to residents. We expect to be able to at least halve the number of parking spaces required in this way. The remaining parking space requirement will be covered in the basement.
The Böhmer ironworks is a former industrial site in Witten, where a company that prospered for many decades shaped urban development and has left its mark to this day. From the 50s and 60s of the 20th century until the closure of the company in 2020, structural development was always geared towards demand. The original industrial building stock is largely robust in substance, can be used flexibly due to its structure and has now been integrated into a mixed-use agglomeration as a result of unplanned development processes in the surrounding area. Today, large volumes of buildings with no specific use can be found in the vicinity of small-scale commercial enterprises, residential infrastructure and various residential buildings - a typical mix for the Ruhr region.
Activation
The building fabric is robust. Although it must be technically adapted to future requirements, there is no compelling reason for large-scale demolition. The existing buildings and the spaces in between not only shape the perception in the neighborhood, they also offer the best conditions for a comprehensive transformation process: the buildings are largely preserved. They are neutral in terms of use and are ready for short-term activation. For example, some of the halls of the former foundry are already being used as logistics space and may be activated in the long term for the “last mile”.
Each building is examined: for its structural quality, adaptability, “gray energy”, resources, future energy requirements, flexibility of use, fire protection, etc. In this way, targeted structural measures can be taken to secure the substance in the long term, to provide new uses in the short term and thus to generate the necessary income for the resilience of the portfolio.
Adaptive Idea
The initial aim is to maximize the adaptation of existing buildings - irrespective of any monument conservation assessment. Research evaluates the possibilities for transformations. The metalworking shop becomes a market hall, the assembly hall becomes a food court. Distinctive building typologies - “Blitz” - are preserved and integrated into the concept in a way that shapes the design and creates identity:
New building configures/contours the future context
Sample warehouse becomes student accommodation
Foundry becomes logistics location
Workshops may or may not remain workshops
Assembly hall 1 becomes a food court
Assembly hall 2 becomes a market hall
Office building becomes new office building or studio/student housing
Sample warehouse becomes student accommodation
Foundry becomes logistics location
Workshops may or may not remain workshops
Assembly hall 1 becomes a food court
Assembly hall 2 becomes a market hall
Office building becomes new office building or studio/student housing
Iterative process: Termination + Re-arrangement
Our proposal is less a concrete urban development concept and more an urban development strategy for gradual transformation and integration. A strategy that keeps options open that are perhaps not yet known today.
This is why conversion, demolition and new construction follow an iterative process. What stands in the way of development or is no longer needed is removed - if necessary, the material is recycled. Demolition and reorganization create new places, new identities - the visible/perceptible/contextual transformation process begins for everything that characterizes urban life: Eating + drinking, living, children, old people, doctors, care … „… come on you raver, you seer of visions, come on you painter, you piper, you prisoner, and shine …”.
“Housing” is becoming an important building block here. Existing buildings will be converted in various forms, e.g. the model warehouse on Westfalenstrasse, or new buildings will be constructed. To this end, we have developed a typology from the large-format, early assembly halls (not foundries) that offers differentiated spaces on a compact foodprint - flexible in use (residential, care, commercial) and adaptable and can offer variable-use spaces with greater room height on the first floor. In this way, the future urban scale is derived from the existing building, interpreted in a contemporary way and designed for the future. The load-bearing structure and technical concept (as much as necessary, as little as possible) also allow for future adaptability in these newly constructed building types. According to “Wittener Baulandmanagement”, 25% of the residential construction area will be built as subsidized housing. The floor plan organization of our buildings allows for this.
A central square will link the future and existing buildings and create a tangible, vibrant urbanity. From here, further development stages could open up the adjoining areas to the east - with residential buildings that take up the existing grain and formally follow a curved line. To the north, they face a public street (play street); to the south, private gardens are set up for the residential community. In this way, a “stitching” of new and old can gradually be created. A public thoroughfare - for pedestrians and cyclists - is to be created towards Erlenweg.
Mobility
In the future, there will be three types of traffic here - motorized, non-motorized and commuter traffic. We offer parking spaces at a central location in a garage.
Commuter traffic - logistics and commercial enterprises - will drive into the industrial estate via Westfalenstraße / vehicles for supply and disposal or ambulance transport will frequent the area temporarily and can use all roads - as can private deliveries.
Pedestrians and cyclists have barrier-free access to all areas
Private motorized traffic can drive directly to the buildings for deliveries and then park their cars in the garage.
Parking: The parking space concept is based on the mix of uses desired by the developer, including care, retail (market hall), medical practices, offices, residential, etc. Accordingly, no underground parking garage is required. Should the requirements/mix change, partial underground parking garages with natural ventilation can be built under the footprints of the buildings.
The property on Königswall is located in the immediate vicinity of the Dortmunder U, the soccer museum, the Kampstrasse boulevard and the main railway station. It is currently developed with a 3-storey office building from the 1950s. In the immediate vicinity, adjacent to the west, a mixed residential and office complex with 3 buildings on a common base has just been built. A high-rise building forms a striking accent and the conclusion on the corner.
The ageing existing building has a clear, simple skeleton structure with a column grid of 4 meters. The original plans envisaged a building with up to 6 storeys. It can therefore be assumed that it is possible to add a storey to the existing building. The building has a full basement.
The current proposal for conversion and extension envisages 6 storeys, with an additional penthouse on the roof. The existing single-storey side wing in the courtyard is to be demolished. There are several options for the courtyard: from keeping it free as a parking lot to a completely single-storey superstructure as a ground-floor office extension of the front building with small green inner courtyards.
The planned conversion of the front building will have 1 or 2 office floors on the ground floor and 1st floor and apartments above, either 1-room apartments or 2-3 room apartments, some as two-storey maisonettes. A particularly spacious penthouse apartment, also extending over two floors, with a roof terrace and roof garden is planned for the top floor.
Access to the building will be completely reorganized with a new staircase and elevator on the street side. All units will be accessed from here. Up to 6 apartments are connected on each of the apartment floors. While the wet cores are largely predefined, all units can be designed as open spaces or with room divisions. The entire building is planned to be barrier-free. The building can be accessed from Königswall and therefore does not require a second escape staircase.
The new exterior design of the building is intended to attract attention with an expressive façade. This consists largely of curtain-type prefabricated elements. Their alternating suspension creates a dynamic and exciting façade appearance. At the front, the view is further enlivened by protruding bay windows. On the western front side, the façade structure is led around the corner and can have windows despite its location on the property boundary due to the existing neighborhood approval. The south side is to form an attractive and pleasant outdoor space with projecting and planted terraces, thus improving the quality of the courtyard. In conjunction with the planned new residential building on the opposite plot on Schmiedingstrasse, the character of the entire quarter will soon meet today's demands for a high-quality, inner-city living and working environment.
The Urban Center Neu-Hohenschönhausen project is to be developed in accordance with the basic principles of ecological and social sustainability, a new hotspot of urban biodiversity, a green hub in the ecological system of the metropolis. Municipally controlled urban development based on public housing companies and cooperatives can prevent the negative effects of speculation and gentrification. The planning implements various standards of green in order to radically improve the social and ecological quality of the urban context. By combining nature-based solutions with the help of innovative and sustainable technologies, new qualitative, spatial and livable standards are created. The aim is to create a modern and lively new urban district. In the medium term, Falkenberger Chaussee will be rethought as a lively green axis in connection with the transport transition and electric motorization.
The available plot of land with a surface area of around 6 hectares will be divided into three building plots: Building plot 1 along Falkenberger Chaussee: A large entrance pergola with a market hall marks the beginning and creates a connection with the neighboring shopping center. Living and working areas will be accommodated in a large modular and hybrid city shelf in two sections. With its perfect southwest orientation and green terraces, it fulfills people's desire for contact with nature and for sufficient open space with privacy. All infrastructure facilities of the new district, small shops, library, theater, family center, and an above-ground neighborhood garage for 200 cars will be integrated into the city shelf. A green high-rise building forms the signature.
Construction site 2 west of the cinema: The Berlin apartment block is being rethought, diagonally and modularly, with a diverse mix of apartments, duplex apartments if possible, townhouses integrated on the ground floor and first floor with direct access, enclosed and green inner courtyard, allotments in the courtyard and on the roof.
Construction site 3 east of the cinema: A cooperative quarter is planned here with a participatory planning model for alternative and communal forms of living and working, 30% cluster apartments + commercial/creative workshops + a public and green courtyard for community activities outdoors.
A completely CO2-neutral wooden city with model character is proposed. With wood from urban planning to the execution details, the new urban district also gets its own aesthetic identity. The creation of vertical and horizontal green spaces contributes to the character. Modularity and flexibility of the building elements in combination with simple and robust structures should promote longevity and a continuous mix of uses.
The interface between living and the city is formed by the ground floor and access zones, as well as arcades and staircases. The aim is to create lively spaces with a variety of uses and community offers. Courtyards and small, intimate squares offer village security, but also the opportunity for networking, new urban hotspots.
ECOLOGY
The use of state-of-the-art irrigation and rainwater collection systems and the selection of native plants - with high CO2 storage capacity, removal of air pollutants and attraction for pollinating insects - are among the core points of the project to increase comfort in the buildings and the well-being of the community. The new district is to have car-reduced living. The central district street will be traffic-calmed and developed as an Active Street.
In line with the ecological approach, Falkenberger Chaussee will be intensively greened and calmed with new rows of trees. A municipal sports park with covered sports fields will be built along the railway tracks in the green embankment under the railway overpass. On the south side of Falkenberger Chaussee, a new attractive train station with an integrated mobility hub (car sharing, e-bike station, bicycle parking garage) is planned in the form of a large roof folding over the tracks.
