KAWAHARA KRAUSE ARCHITECTSKKA

At the end of the 1940s, Werner Kallmorgen designed the Klingenberg neighbourhood for the British military government. Two-storey terraced houses with a converted attic and pitched roofs were built, with two flats planned for each house. The houses were later sold privately, the terraced houses with separate flats were converted into single-family houses and the floor plans were adjusted accordingly. The starting point for this remodelling project therefore was a house with low ceilings and a small, nested room structure with thin walls.

The conversion of the house was characterised by the desire for more openness, light, and spaciousness. To achieve this, partition walls were removed, and the floor plan was reduced to its essential basic structure: the division into four quadrants, half along the north-south axis and slightly off-centre along the chimney flue in an east-west direction. The design formulates the boundaries between the quadrants as flowing transitions both in the storey levels and between the storeys. The relocation of the staircase from the entrance to the southern living area through a newly created ceiling opening ensures a light-flooded vertical connection through the entire house.

The house is entered on the north side via a spacious entrance area, which opens via sliding doors to the open-plan kitchen or directly to the living area. The living area is characterized by the double height space to the first floor. A wraparound gallery around the opening on the first floor provides visual connections, while the master bedroom can be separated from it via sliding doors. The south-west quadrant of the floor plan thus becomes the connecting element of the house across all levels thanks
to the double height space, the gallery, and the new, open staircase.

As part of an ideas competition for floor plans for a linear building block with a north-south orientation, a strong basic structure was proposed that is easy to build and transferable to other projects. On the one hand, it should be modular and consist of only a few elements in order to enable a high degree of economical prefabrication and, on the other hand, characterise the building in its spatial structure and character while offering as much flexibility as possible. The aim is not only to build economically, but also to create a durable building that can be adapted to shifting needs: a serial production with individuality and the ability to change.

The repetitive structure consists of columns with a square cross-section and L-shaped walls. The formation of the L-shaped walls supports the floor plan layout, which is orientated radially from the central access to all facades. On the one hand, the L-shaped walls feature a neutral uniformity across the entire floor plan, but at the same time stimulate the characteristic spatial structure. They are a space-defining element that unites the load-bearing structure, pipework and interior finishing. With just two different opening widths, the basic structure can be flexibly finished and changed into different room sequences.

The open staircase on the north side of the building forms a balcony area on the landings, alternating left and right, which can be used by all residents as an additional outdoor area. These stair balconies are accessible via the intermediate landing and are therefore at split level with the entrance balconies. The alternating left and right arrangement results in an airy and bright double-height space. Thus, a circulation system is created that is efficient, lets light through to the entrance balconies and the façades behind, and at the same time offers space for encounters.

For this exhibition on Hamburg’s architecture competitions of the recent years, we decided to make the huge wealth of the about 200 competitions – expressed in about 1.500 ideas and 6.000 plans – all together visible, instead of showing only selected competitions or competition entries. Not only the winning design of a competition is important, but each individual competition entry has a value in itself and contributes to the discussion about the future development of the city. Each work stands in relation to all the other works and is defined by others and vice versa. Together they allow for new readings and narratives that will shape the entire city.

Most competitions are submitted as printed plans – which we used as a medium to design the exhibition. In a spacious former warehouse, 1.100 banners (3m long and 90cm wide) were hung from the roof in long rows. Together, they build a hovering spatial body that we regard as a floating archive of ideas. The competitions printed on the banners are arranged by districts and within the district by chronological order. The competition entries are not shown with the winning projects first, but alphabetically according to the offices ‘names. This neutral order is reflected in a code that was given to each competition, each entry, each plan – representing the concept of an archive of ideas.

The plan of the floating archive shows the parallel rows of the banners crossed by wide and narrow paths. Along the wide paths, so-called islands are arranged, creating separate exhibitions spaces within the floating archive. Here the major tasks of the city planning are featured: Residential, Office/Commercial, Infrastructure, Public/Green Spaces, Culture/Education/Sport, Conversion/ Re-Use, and Urban Planning. Each island showing one of these themes has a unique geometrical shape and colour. The plan of the exhibition resembling a city is to visualise the importance of this first-time show of all competitions together as the sum of all contributions to the entire city

The completed L-shaped pavilions of the first construction phase of the western Karl-Marx-Alle show a strong differentiation between the side facing Karl-Marx-Allee and the side facing the neighbourhood street, both in terms of their façade design and floor plan. While a spacious, two-storey room faces Karl-Marx-Allee, the other side is characterised by a small-scale room layout as a serving part. Within the existing pavilions, only the pavilion on the corner of Schillingstraße (‘Camp4’) deviates from this principle of separating the two arms of the L into serving and serviced parts.

The new L-pavilions at the beginning of Karl-Marx-Allee represent a special situation. Due to the square situation in front of each pavilion in the direction of Alexanderplatz, these two pavilions have a showcase side on both legs of the L in terms of urban space. The two L-pavilions therefore have a two-storey space over the entire length of both legs of the L, with no functional separation between the two legs. The two special L-shaped pavilions thus create a typology that clearly marks the beginning of the series of different pavilions on Karl-Marx-Allee.

The exterior appearance of the L-pavilions is based on the realised pavilions of the first construction phase. The interior, on the other hand, is characterised by a visible wooden ceiling structure. The ceiling structure arranged at a 45° angle is intended to counteract a hierarchisation of the two arms of the L. Instead, the connection of the two legs emphasises the permeability of the corner and thus the urban significance at the beginning of Karl-Marx-Allee.

The new façade of the Besenbinderhof is a clearly structured element façade. Prefabricated concrete elements are hung in a grid of 3.2 metres. Compared to the existing façade, the seemingly larger grid creates a visually generous impression. In between, ceramic elements cover the 1.6 metre grid of the existing building and give the new façade depth and rhythm. The width of the concrete elements decreases on the upper floors, gently zoning the overall façade into a base and an upper area.

The intersections of the vertical and horizontal elements are articulated, their surface texture stands out from the other elements. The interplay of the elements, their dimensions and arrangement create a new tectonic clarity. The stone slabs from the existing façade are removed and directly reused as high-quality floor and wall panelling for the new entrance hall. The resulting stone chippings are added to the new concrete façade as an aggregate. The new façade is thus reminiscent of its predecessor.

The new façade derives its decorative character primarily from the surface texture of the materials. It consists of concrete blocks coloured in a light brown-beige, whose formwork creates a roughly structured surface similar to embossing. However, the pattern by the formwork, which is always the same for economic reasons, is given an always different appearance by adding the stone chippings from the existing façade. A high-strength concrete is to be used, which allows significantly lower material thicknesses and thus material savings. It does not require reinforcement, which increases future recyclability.

Belvedere is built in Hamburg’s central park Planten un Blomen as part of the “Hamburger Architektur Sommer” (the Hamburg architecture triennial) and to mark the 30th anniversary of the city partnership between Hamburg and Osaka. Designed by KAWAHARA KRAUSE ARCHITECTS and with a colour concept by Japanese artist Nobuko Watabiki, the pavilion functions as an interaction of art and architecture and creates a quiet retreat in the fluid space of the vast park. As a public platform it invites visitors to enjoy and experience new perspectives of this popular and familiar park.

With the pavilion being a temporary structure of only four weeks, the possibility to disassemble it into its components played a big role in the design process as much as the choice of the construction materials. Developed as a reciprocal structure, the structural system consists of many small, easy to handle elements. Next to being easy to transport and assemble without the use of big machinery, this also allows for a simple construction on site. Only reversible joints (interlocking or screwing) were used in the pavilion as to guarantee the recyclability of the materials wood and paper after dismantling.

The roof structure is made of cardboard. On a single curved line, rectangular sheets were cut into two parts without wasting material: a convex and a concave part. By assembling the convex and concave parts in different directions in addition to the differing colours chosen by Nobuko Watabiki, this very rational roof structure now appears layered and multi-faceted. Depending on one’s viewpoint, the concave and convex elements seem to either align neatly, or interlock arbitrarily

The so-called Strandlust was a hotel and restaurant at the ferry terminal in Bremen Vegesack, regionally known for decades as a special place for celebrations and festivities. In the course of planning a new replacement building, the surrounding site was to be developed as a new residential area. Due to the direct location at the river Weser and the lack of flood protection, the area was to be designed on a terp level, while at the same time establishing good connections to the (not flood-protected) promenade in front of it.

On the level raised by the terp storey, the design for the new residential area features buildings as free-standing, slightly twisted volumes that form squares that widen and get narrow again. Thus the neighbourhood becomes open in all directions and permeable to walk through. The various views on the river between the buildings stage this special location. The design makes a clear distinction between the edge of the landscape as a retaining wall concealing the terp level, and the buildings, as such clearly reaching down to the lower level of the promenade.

The New Strandlust stands out from the neighbourhood as a prominent solitaire and will become a landmark on the Weser with its individual architectural language. Its round base storey protrudes distinctly from the retaining wall and forms a spacious terrace with a unique view above it. The building volume plays with strong geometric shapes that form another roof terrace, a cantilevering half-round volume providing shading to the terrace and a higher part of the building with inclining roof for good visibility even from a distance.

The remodeling of an old stone house in western France was to give the house a new order, make it more spacious inside, but at the same time preserve its unique character. Together with some lower annexes, this 1850 house forms a courtyard which serves as the entrance. To the rear of the house is the garden. The building ensemble is built in locally sourced stone, the main house has timber ceilings. Before the remodeling, the inside was divided into cellular, winding rooms with thin, non-load-bearing walls in contrast to the very thick, solid exterior walls.

All interior walls were removed. After the remodeling, the ground floor consists of only one large, open space. Shelves on the outer walls provide necessary storage space and underline the character of the room. The space is now characterized above all by the symmetry of the entrance door and the four windows either side of the courtyard and garden, as well as the presence of the solid stone exterior walls. Along the existing wooden staircase, a shelving unit protrudes into the room, creating an open zoning. Upstairs, built-in wardrobes and shelves form a new room structure.

The clients‘ wish for conservatories either side of the house was further developed into a spatial sequence. The first conservatory acts as a threshold and entrance between the courtyard and the now large, open living space, while the second represents the transition to the open garden. The two conservatories are characterized by a diagonal wooden grid, the structure of which was then adopted to form a pergola framing a „green room“ in the garden - a spatial counterpart to the courtyard on the other side of the house.

In the transition from outside to inside, from private to public, the threshold reconciles different functions or characteristics on several levels, ediating between city and house,between house and apartment, between community and individual. Commonly known reference projects from across the newer architectural history were chosen for the exhibition regardless of their typology or size, aiming to set a new focus onto the familiar to discover meaning and potential of threshold spaces. With the help of models the spatial phenomena of thresholds is explored in a playful serial examination.

Each architecture holds many thresholds and threshold spaces. They can be found in various scales. At the same time their morphology can easily be transferred into different scales. Therefore the scale does not play a role in the exhibited models. The projects were rather adjusted in their proportions and extracted area to a unitary absolute size instead of a relative one, in favour of a universal validity. Like in a test tube where substances are seen in a new light, a cube of 10x10x10cm serves as a frame of observation. In this imaginary test tube the interpretative reconstruction of the fragments is condensed to morphological diagrams of possible variations of thresholds.

Like a cabinet of wonder, the medley of objects taken out of context offers a repertoire of inspiration and curiosity. The model table with its endless rows of spatial diagrams aims to feed the imagination of how our living together in the city may be changed by threshold spaces without providing a solution to a concrete situation. How would the city, the house, our community change if the threshold spaces were to be applied more consciously?

“Alter Friedhof” in Rheine is a former cemetery that is now used as a park. An open library was planned to encourage the use of this park with its huge, old trees. To the people from the neighbourhood it is an opportunity to exchange books. In contrast to the open book cabinets that have recently become very popular in German cities, it is designed not only to provide a place for exchanging books but also an open library inviting people to read the books on site and thus adding a new function to the park.

The building nestles at the foot of the old trees, its contour and volume are defined by the open spaces between the trees. The open library is a truly open building. The soil remains visible within the building and the open structure makes it accessible from all sides. However, the low reaching roof provides shelter from the rain and the wind, creating an intimate and protected space.
The inside of the open library is arranged around three big “book shelves” embracing three courtyards and drenching the introverted space with plenty of light.

The shelves also have a structural use. A single structural system was developed for the walls and the roof of the building: short and therefore economic timber planks are arranged in a windmill layout forming a continuous grid structure doubling up in the walls, thus creating book shelves. The roof is covered with oversized wooden shingles, its overlaps leaving small slits that allow the light to fall inside

The starting points for this project were two completely independent circumstances. One was a heap of firewood in the client's garden that needed a place to be stacked and dried. The other was the wish of the religious clients for a place of contemplation and prayer in their house. The design for the wooden hut combines these two different wishes. It is a small private chapel in the clients' garden that is built of firewood.

The hut consists of five wooden frames that are stacked with firewood, thus forming the outer walls. The comfortably dim space inside is spotted by countless rays of light sparkling through the logs. In the course of time, dried wood is being used and replaced by new wood resulting in a constant change in the walls of the hut. The stacking pattern changes as well as the colour of the wood.

The space is created by only two walls. They open up towards the entrance and narrow the space towards the cross thus directing the movement to the inside. The deep roof shades the space underneath while the wind passes through the hut in summer. By using the on site firewood in the garden and granting it a new use, an unusual space emerges just a few steps outside the house providing a shelter for contemplation and prayer away from daily life.

“Line, surface, space“ is an installation that plays with the perception of space. A fragile structure of threads stretching from floor to ceiling seems to dissolve in space and recompose to ever new appearances. Varying between transparent and closed surfaces, the spatial perception changes with each step taken through the installation. It is erected on the plan of three interlocking twisted squares of different sizes. While the threads of the outer square suggest the edges of an imaginary space, the more denselyarranged threads towards the middle seem to create surfaces. Ordinary threads evolve into lines in space that create surfaces which seem to comprise spaces. Lines and surfaces overlap in various constellations in space. Thus a fragile structure evolves on the plan of the three squares that constantly changes its appearance on approaching, walking around or through it, creating ever new impressions.

The structure blurs the thresholds between line, surface and space. It offers a new perception of these three ideas and a new understanding of how much needs to be defined in order to make them perceivable. Impressions when moving through the installation are complex; the ambiguous overlapping of the threads - as single elements hardly visible - seems to make the space even more perceivable though.

Financial restrictions encourage us to question essential principles that are usually taken for granted and see them as opportunities to develop a new architecture. In the installation “line, surface, space“ new spatial experiences are created by providing ordinary woollen threads with a new use. The Japanese artist Nobuko Watabiki painted some of the threads, so that colourful areas materialize on the surfaces by the interaction of the threads. Painted areas overlap and keep on changing their composition as one progresses through the installation, affecting transparency and perception of the surfaces and the space.