A new hybrid city block has been completed in Hamburg. The KPTN building ensemble sets an example of how to build a compact city that is functionally and socially mixed. The development designed by blauraum architects combines about a dozen different functions under one roof and brings liveliness and diversity to Hamburg’s HafenCity.
Its cinema, the Hafenbühne stage, restaurants and bars are points of attraction, particularly in the evening. Together with the Pierdrei hotel, longstay apartments, shops and a public underground car park, they attract a wide range of visitors. At the same time, the KPTN is home to a wide variety of residents lilving in 220 free and subsidised apartments, in efficient single-room apartments or family-friendly three- to four-room apartments. There is also space for retreat and a quiet chat on the roofs with their playgrounds and garden gazebos, as well as a planted inner courtyard. The quarter is crossed by a passage way that, in the middle, widens out to a plaza which with generous outside seating and eateries. Thus the KPTN creates not just new residential accommodation, but rather a small “city within the city”.
Reminiscent of the Speicherstadt
In spite of the highly diverse functions, the ensemble presents as a unit with a clear outline. The total of five buildings with their richly varied longlasting brick facades resonate with the neighbouring Speicherstadt, a UNESCO world cultural heritage site. With its special brick bond, the facade of the hotel/cinema complex designed by Nalbach & Nalbach is inspired by North German brick expressionism and creates a particular pattern with its protruding and receding bricks. The simplicity of the external facades of the residential and commercial block is reminiscent of that of the storehouse architecture, being based on a clear symmetrical pattern in which storey-high window elements are arranged. Due to their deep reveals, the French doors provide openings to the outside without significantly protruding into the street space.
Adaptability and longevity as basic principles
The storehouse buildings of Hamburg’s historic Speicherstadt served as inspiration for blauraum also in their open and flexible building structure. The KPTN could be seen as a modern hybrid city warehouse that is able to respond to changing requirements. Small apartments can be combined to form larger units and shop areas can be flexibly sub-divided. Sustainable building is thus defined as long-term adaptability.
The materials were selected with a view to a long service life: durable, weather- and abrasion-resistant surfaces and low-maintenance windows and door frames, reversible connection methods of components that can easily be replaced. The omission of foam sealant as a fitting material and the low-maintenance, long-lasting brick facade support the same aim. The KPTN makes sustainable use of resources and, in terms of energy consumption, uses significantly less primary energy than is permitted by the German Energy Conservation Directive, EnEV 2009. The new building has been entered for the HafenCity (Gold) certificate, an environmental accolade that takes its cue from the DGNB certification scheme.
A complex building: providing flood defences and sound insulation
The project is also frugal in terms of space: 45,600 m² of GFA is located above ground on the 6,400 m² site, spread over seven to eight stories, with two stories located underground. In view of the fact that the development was built on the site of a filled-in port basin and lies up to 2.5 m below the flood protection level, special devices were necessary. For example, the hotel/cinema complex is surrounded by a flood protection balcony installed as a characteristic design feature.
The direct proximity of contrasting functions presented an interesting design task. Above the cinema are hotel rooms, which are supposed to provide guests with a quiet, relaxing experience. For this reason, the cinema auditoriums were built as complex room-within-a-room constructions supported on brackets or resilient elements. Likewise, sound insulation plays an important role for the micro-apartments that face towards Am Sandtorpark street. The windows of the residential block were specially developed, featuring storey-high opening elements with soundproof glazing. These innovative HafenCity windows with fixed solar screening and sliding door elements allow for natural ventilation without lessening the sound-reducing effect.
blauraum Architects is an innovative, award-winning company with branches in Hamburg and Berlin that is characterised by the quality of its design, by sustainability and an interdisciplinary style of working. The blauraum architects’ practice was founded in Hamburg in 2002. The managing directors of the practice are Prof. Volker Halbach, Prof. Rüdiger Ebel and Carsten Venus. We are a concept-oriented practice and, with approx. 60 members of staff, work on complex projects at various scales throughout the Federal Republic. Our diverse portfolio comprises housing, offices, and cultural and educational projects in the public and private sectors – from urban masterplans through to items of furniture.