Bremen
Like many German cities, Bremen is confronted with an increasing housing shortage and a growing demand for affordable housing.
In response to this, the largest Bremen Housing Association, GEWOBA, has prudently taken on a supplementary extension to their existing 45,000 plus housing stock. In 2011, within the framework of the competition “ungewöhnlich Wohnen” (unusual living), five exemplary lots from a postwar housing area were chosen to investigate the adaptability of the area. The proposals considered contemporary demands for affordable and flexible housing that could offer manifold inhabitant configurations. These housing areas in the Gartendstadt Süd of Neustadt Bremen, offer generous green open areas formed by homogenous four-storey housing blocks.
Cube House
Like many German cities, Bremen is confronted with an increasing housing shortage and a growing demand for affordable housing.
In response to this, the largest Bremen Housing Association, GEWOBA, has prudently taken on a supplementary extension to their existing 45,000 plus housing stock. In 2011, within the framework of the competition “ungewöhnlich Wohnen” (unusual living), five exemplary lots from a postwar housing area were chosen to investigate the adaptability of the area. The proposals considered contemporary demands for affordable and flexible housing that could offer manifold inhabitant configurations. These housing areas in the Gartendstadt Süd of Neustadt Bremen, offer generous green open areas formed by homogenous four-storey housing blocks.
Cube House
The high adaptability and multiplicity of the modular prefab timber system makes the Bremer-Punkt a pilot project for supplementary extensions to social housing on an urban scale.
The urban niches are activated by the punctual integration of four-storey timber cubes. With a surface area of only 13.35 x 13.35m, the cube houses react sensibly to the existing buildings, granting the character of the green open spaces of the estate to keep their appearance. The new buildings are designed as a modular timber prefab system. This system allows flexible layout possibilities for site specific needs and responds to individual demands. The houses can adapt to differing apartment combinations, surface area, circulation, facade, and building form requirements.
Prototype
In February 2017 the first three Bremen-Cubes will be completed in the Gartenstadt Süd.
With a 44-58m2 living area (two to three rooms), these smaller apartments succeed in providing affordable housing with a higher than average standard of living, timber construction system, generous window openings, spacious private outdoor areas, and optimised south-west orientation. The new buildings present an upgrade to the housing stock and the local area, and afford existing tenants intergenerational equity, specifically for those requiring barrier-free design solutions. A collective living project is housed in the third Bremer Cube, adding new energy to the area.
From Prototype to Serial Housing
From the conceptual idea through to the finished and final serial housing typology, an intensive design process has been applied.
The cognisance of the planning process for the prototype was evaluated and developed with regards to construction methods, site development and spatial efficiency optimisation of the new constraints. The Bremen-Cube has been worked through as a multiplicitous, serial housing typology. It realises contrasting housing mixes with predetermined apartment layouts of different sizes and organisation. The new addition offers more layout variability and more useable living space. The optimised building envelope provides the building with a good energy efficient surface-area-to-volume ratio. At present there are seven Bremen-Cubes in planning and realisation, in the districts Neustadt, Kattentum and Schwachhausen – followed by more buildings to be implemented.
Floor Plan Kit
The Bremen-Cubes can accommodate up to eleven apartments per building. The floor plan kit showcases a catalogue of twenty-two apartment typologies, which have the possibility to be combined with each other in over sixty variations.
The serial building typology compliments the existing housing with new flexible and barrier-free floor plans. The apartment sizes range from a one-room apartment of 30m², to a six room apartment with 138m². The multiplicity and customisation of the apartment configurations ensures that each site is able to offer an individual proposal to differing user-groups. All the apartments are barrier-free and two apartment typologies are fully wheelchair accessible.
Inhabitants
The open plan layout allows for multifaceted living models; living and working are equally conceivable as are many possibilities of family constellations, single households or collective living forms.
Within the context of current affordable housing demands and discussions on living space requirements, the Bremen-Cube offers flexible and site-specific proposals for public or privately funded models, providing a high social mix and intergenerational equity. Nineteen of the twenty-two apartment typologies fulfil the requirements of the “Bremer Wohnraum-Förderungsprogramms” (Bremen housing funding board). The third Bremen-Cube will be realised in cooperation with the “Martinsclub Bremen e.V.” as an exemplary community housing project. The project looks to house a heterogenous mix of young people and elderly, disabled, refugees and lowincome persons and families together. The GEWOBA has complied a floorplan catalogue of the versatile combination possibilities of the housing typologies.
Living Quality
A full height glazed loggia is connected with the kitchen, creating a spatial extension, which becomes an integral part of the living area.
This combination of loggia and kitchen creates a high quality living space, where cooking, dining, playing, and gardening are made possible. The green living quality is accentuated on a variety of scales through the careful placement of the cubes, as well as with the large facade openings with their immediate connection to the outdoor vegetation. The open circulation balcony is a meeting point for the inhabitants, and forms a node between inside and outside. The second generation will offer higher flexibility for different apartment typologies and sizes. Through the use of large sliding doors, rooms can be closed off, divided or extended according to need.
Facade
The abundant, playfully arranged square openings reflect the differentiated internal living arrangements of the cube-houses.
A combination of the wooden windows and timber loggias reviews the timber facade construction of the Bremen-Cube. The recessed volumes and the large openings animate the contrast between the massive cube and the light appearance of the facade. Illustrated in the individual facades of each new building the Bremen- Cube develops a site specific customised character, which contrasts to the postwar housing estates. The building's envelope can be produced in plaster, or as timber facade under specific circumstances.
Orientation Through Colour
The specific identity of the individual Bremen-Cubes is accentuated through a colour concept.
The city wide extended Bremer Grün marks out the first three Bremen-Cubes in nuanced gradations. Loggias, entrance thresholds, a sculptural landscape object close to the entrance, are accentuated though the use of colour. The signifying object could be a large rock or an old tree stump. The playful intervention gives a distinctive identity and an orientation marker to each building for the inhabitants as well as for the surrounding area.
Timber Modular System
The Bremen-Cubes are a modular construction system conceived and made up of predominantly prefabricated building elements.
This type of construction system allows for the realisation of differing floor plans in size and organisation. The standardised system is suited to the building being erected in the shortest possible time and with minimal construction site organisation and disturbance. The load bearing outer wall elements are made in a timber frame system. The floor elements are reinforced concrete or optimised Timber-Concrete Composite (TCC) elements. The circulation areas are conceived in reinforced concrete which strengthens the building's horizontal loads and serve as the primary escape route. This can be designed as either an inner core or as an open circulation balcony core.
Sustainability
Timber construction materials are renewable and environmentally friendly, with a considerably low “grey energy” consumption.
In comparison to commonly used commercial construction methods, considerably less “grey energy” is consumed in the complete life-cycle process of timber: from raw materials to material waste disposal. The Timber-Concrete Composite floor system has a weight reduction of 50%, and a reduction of CO2 emissions of up to 90%. The Bremen-Cube will receive a “NaWoh” certificate, from the “Vereins zur Förderung der Nachhaltigkeit im Wohnungsbau e.V.” (German NGO for the advancement of housing sustainability). The assessment criteria takes into consideration socio-cultural factors, functionality, technical factors, as well as life cycle costs, long-term value, environmental compatibility and health impact assessment.
Energy Concept
The energy concept is based on a highly insulated building envelope, which roughly correlates to a passive house standard, fulfilling the “standard KfW Effizienzhaus 55”.
Energy and water usage is almost completely covered by the individual house's solar panel facility and a heat pump with an accumulator. The ventilation system is designed over a central exhaust-air facility on the roof, which draws in clean air through the trickle vent system in the window frames. Domestic hot water is powered by local electric water heaters in each apartment, and underfloor heating with low supply temperatures helps additionally to save energy while providing comfort. The Bremen-Cube fulfils the “Standard KfW Effizienzhaus 55” with a yearly primary energy use at a maximum of 55% of reference buildings from the “EnEV 2014” (German energy conservation regulations).
Economical Factors
Long-term developement to serial production.
Designing tailored solutions for different locations and demands by means of generating positiv synergestic effects, requires an extenisive development phase. The experiences with the first realized prototypes serve the further development up to the serial maturity. Once this step is completed, the number of "unknown" is reduced. The building types are well-known to the authorities, the planning takes advantage of repetition and the construction process is going more fluent. The evaluation process continues until these synergy effects can be included.
