Project type: Urban Planning, Office, Residential
Location: Berlin, Germany
A new quarter is being planned for one of the most prominent locations in Berlin next to the main railway station, opposite the Museum of Contemporary Art and bordering the government quarter. The exceptional site, situated on a bend in the river with a 270° waterside frontage, also closes a long-unresolved gap between East and West Berlin. As such, it has the potential to become one of the most frequented areas in Berlin.
While its location on the Invalidenstraße offers excellent transport access for both residential and office developments, the rear of the site to the south and east faces the river and is more tranquil. The preliminary development plan proposes a waterside walkway for this section. GRAFT’s design seeks to make optimum use of the site while strengthening the site’s characteristic qualities for both retail and residential uses.
Given the large scale of the land parcels defined in the masterplan for the main railway station, it is doubtful how legible different residential and office constellations will be in relation to the overall mass and identity of the two urban blocks. GRAFT’s design proposal therefore focuses on developing a common appearance for both blocks by means of a façade pattern that is flexible and adaptable enough to respond parametrically to the respective functions and unit sizes that it fronts. The façade’s DNA is expressed through a repeating formal structure with a polygonal modulated three-dimensionality. This repeating element adapts to meet different needs – reflected, stretched to twice its width, wrapped around a bay window or used to form a balcony – giving the façade an animated but also consistent appearance.
For offices, a narrow bay width of 1.35 metres affords maximum flexibility for variable office unit sizes, while a twin-bay width of 2.70 metres is more appropriate for residential purposes, defining the position of cross walls and duct cores for the rooms behind. By angling these elements outwards from the façade plane, bay windows can be created, often in conjunction with balconies that afford a better view over the Humboldthafen, especially on the east and west elevations. They act as a transitional zone between inside and outside, extending the private sphere of the interior outwards onto an attractive outdoor area but without sacrificing the residents’ sense of privacy.
The rhythm and appearance of the façade changes depending on one’s viewpoint, highlighting sometimes the patterned uniformity of the facades and sometimes the pronounced surface modulations of the relief and angled protruding bays. At ground level in the public arcades and at roof level where the façade steps back to create private terraces, the standard module is varied in height to reflect the scale while remaining part of the overall pattern. The arcaded walkway along the waterfront of the Humboldthafen widens to form a south-facing waterside terrace with adjoining café. With its spectacular view south over the water and the passing trains and boats, it is both the public face of the building and a theatre auditorium with public arcade below and private loggias and balconies above: a theatre-like backdrop with the city as its stage.
All parts of the building are accessed directly from the street with access to the apartments via stairwells designed as fire stairs. The residential areas are laid out to maximise the number of apartments with living areas overlooking the peaceful inner courtyards. Flexible office spaces are arranged towards the Invalidenstraße while the ground floor is predominantly occupied by retail units. The upper floors, by contrast, are predominantly residential. To achieve a greater variety of apartment types, the apartments on the south-east section of the site, as well as on the first floor have terraces. The rooftop studios likewise have spacious terraces and private roof gardens. A section of the roof serves as a communal roof garden. All areas can be reached directly from the underground car park.
Construction – The building is a steel frame building with slab floors and rigid cores for reinforcement.
Landscaping and green areas – The outdoor areas reflect the requirements of the brief. To the north, the hardscaping blends into the urban realm while in the direction of the Humboldthafen, the ground terraces downwards, flanked by private and partially semi-public terraces, towards the public arcade along the waterfront. Different paths run through the site forming small terraces to stop and enjoy a coffee.
Sustainability and energy concept – The design concept proposes a flexible, rational and sustainable building that meets modern-day requirements without polluting soil, air or water. It minimizes energy and water consumption through a combination of the ‘lean-mean-green’ strategy, innovative modern technologies and the use of renewable energy sources. The holistic approach outlined in the competition proposal already takes into account sustainability aspects that offer numerous benefits over conventional buildings: reduced environmental impact, better user satisfaction, lower life cycle costs, greater property value and increased productivity to mention just a few.
The design of the new buildings follows a holistic approach that considers ecological, economic and socio-cultural concerns from the outset to achieve a result that is not only cost-effective but also environmentally-friendly and sparing in its use of resources. This sustainability concept intends to ensure a high-quality building and stable market value while also being able to adapt and respond to future developments.
The following key aspects of the design should be incorporated in the final building:
– The total primary energy demand is significantly below that of the reference building (according to EnEV2009 / DIN V 18599) as is thermal heat loss by transmission and the heat transfer coefficient.
– Energy and utility flows in the building will be monitored using suitable measurement devices to determine the overall energy consumption, and to measure primary energy demand against the target values.
– Heavy metals will not leach into the water (e.g. through a suitable choice of roof, façade and drainage materials).
– The ground floor areas are for public use, e.g. restaurant, cinema, urban stage.
– Above-average bicycle parking areas.
– Reduced drinking water consumption (water-saving fittings, flow limiters, low-consumption sanitaryware).
– The roof is a usable space (green roof, roof terrace)
– Maximum space efficiency
– Life cycle balance of materials should be below selected reference values.
– High proportion of renewable materials
– No non-certified tropical woods (FSC)
– Lower demands on indoor air quality for less air conditioning and in turn better thermal and acoustic comfort, reduced noise pollution and better user control (indoor climate, lighting and glare). 20% should be suitable for allergy sufferers.
– Special solutions enabling adaptable and variable building elements
– Comprehensive documentation with operator handbook
– Barrier-free accessibility for people with visual or hearing impairments, for people with mental handicaps and for physically disabled people
– Improved durability and flexibility of use
– Incorporation of Facility Management requirements from the outset
Energy concept – All main utilities such as electricity, water and heat to be supplied by local providers. Optionally, a cogeneration plant (CHP) could be used to generate heat and electricity with water from the River Spree for cooling. A heat pump (water/water, water/air) could provide additional energy (heat/cooling). This would reduce dependence on external suppliers for these utilities. The optional solutions entail greater initial investment but result in more economic running costs in the long term (partial independence and faster ROI due to lower connection charges and provision requirements).
Optional cooling could be provided through a heat exchanger system (closed system) utilizing the low temperature of water from the river. Photovoltaic or solar panels on the roof could be used to generate electricity or hot water. Heat protection in summer would be provided by shading elements (e.g. automatic jalousies).
Apartment buildings – The underfloor heating can in summer be fed by cold water from the River Spree for effective temperature reduction, using an automated switching system.
Offices and retail units – The same applies to retail units. Ventilation systems are needed for restaurant areas but in summer the same technology can be switched to use the cooling system fed by cooler water from the River Spree.