Constructing sustainability - Bund.de

Constructing sustainability The Berlin Office of the Federal Ministry for the Environment, Nature Conservation, Building and Nuclear Safety

Contents Imprint Published by Federal Ministry for the Environment, Nature Conservation, Building and Nuclear Safety (BMUB) Public Relations Division • 11055 Berlin • Germany Email: [email protected] • Internet: www.bmub.bund.de/english Text Journalistenbüro Ecoscript, Falk Jaeger Edited by Kerstin Brümmer, Frank Cremer, Horst Grothues, Jürgen Schulz, Reinhold Weigand (BMUB) Technical editing Federal Agency for Construction and Regional Policy (BBR) Design KONZEPTREICH Medienstrategien GmbH, Munich Graphics: Sabine Mascolo, Munich Printed by Körner Premium GmbH, Sindelfingen Published November 2014 First Print 5.000 copies Where to order this publication Publikationsversand der Bundesregierung Postfach 48 10 09 • 18132 Rostock • Germany Tel.: +49 30 / 18 272 272 1 • Fax: +49 30 / 18 10 272 272 1 Email: [email protected] Internet: www.bmub.bund.de/en/service/publications Note This publication is part of the public relations work of the Federal Ministry for the Environment, Nature Conservation, Building and Nuclear Safety. It is distributed free of charge and is not intended for sale. Printed on recycled paper.

Foreword

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The project

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New office on historic site Facts and figures Environment and energy

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A sustainable model building Constructing a passive building – the great challenge • Monitoring: from theory to practice • Sustainable energy management: Heat, light and air • Part of the concept: intelligent-user behaviour • Life-cycle assessments: using the right building materials • Finds of black adhesive and waste oil • Comfort thanks to walls of clay Interview with Uwe Römmling; Federal Energy Officer: “We couldn’t simply turn the building around”

History

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The old government quarter The Reichstag – massive splendour • From Hitler’s balcony to the new Reich Chancellery: The Nazi state moves in • Dust and ashes – great wartime damage • GDR Government uses surviving buildings • The Federal Government in the old government quarter

Moving fate of a building The Kaiser criticizes the architect • Open-house building • Initial conversion work and wartime damage • In the no-man’s-land of the divided city

Architecture

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Exciting interplay of old and new Historical horizons of building site • Art vagabonds in no-man’s-land • Competition between architects • The winning design • The visitors’ centre • Two covered courtyards create new space • Preservation of monuments: interpretation and original • The historic hall Interview with the architect, Jürgen Pleuser: “The building is unmistakable”

Art in architecture Curtain up for shape and colour

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Dear reader, in 2011, the Federal Ministry for the Environment, Nature Conservation, Building and Nuclear Safety (BMUB) moved into its new Berlin Office in Stresemannstrasse, right beside Potsdamer Platz. This building is remarkable in many respects: we are the first federal authority to work in a lowenergy, passive building – in the very centre of Berlin. The special challenge was to extend the old building, which had once served as the Prussian Ministry of Agriculture, while implementing exemplary green concepts in a historical context, at the same time meeting the highest standards of design, functionality and cost effectiveness. This resulted in a model project for modern architecture – in other words, an environmentally sustainable and innovative building. Today, what began as a progressive project primarily from the point of view of environmental protection and climate change, has a dual significance: since the end of 2013, the BMUB has been responsible for the building sector as well

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as the environ-ment. However, for many years previously, the ministry’s Berlin Office was a pilot project for intelligent linking of environmental and building policy, thereby setting a precedent for the ministry’s current responsibilities. And there is another way in which the building characterises the work of the ministry: the old building, painstakingly restored and refurbished, represents an architectural integration of recent German history. It presents parts of the Berlin Wall, and brings together old and new in a dual sense: environmentally aware, while preserving the existing building fabric. My thanks go to all those who have been involved in the planning and implementation of this project. This brochure guides you through the old and new parts of the Stresemannstrasse complex – a building with a special history in the very centre of Berlin.

Dr. Barbara Hendricks Federal Minister for the Environment, Nature Conservation, Building and Nuclear Safety

Foreword

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New office

on historic site The vibrant area around Potsdamer Platz and Leipziger Platz, which has become the centre of the new and old capital city of Berlin, now has an added attraction. In June 2011, the then Ministry for the Environment, Nature Conservation and Nuclear Safety (BMU), now the Federal Ministry for the Environment, Nature Conservation, Building and Nuclear Safety (BMUB), took up residence in its new Berlin Office on Stresemannstrasse. On this prominent site, which reflects more than 100 years of turbulent German history, a unique ensemble has taken shape: a ministry building consisting of the historic monument of the former Prussian Ministry of Agriculture and a new building of environmentally ambitious character. The architectural concept includes parts of the Berlin Wall, which remain permanently preserved as a witness to our recent history – both a memorial and as a symbol of the peaceful new beginning.

of Parliament and parts of the Federal Government in 1999, the Environment Ministry remained one of the few ministries without premises of its own. The new building in Stresemannstrasse eased the situation there. In view of the new scope of the ministry since the end of 2013 and the increased number of staff, additional buildings in Köthener Strasse and Krausenstrasse were used. The central location near Potsdamer Platz means short distances from the Berlin offices to Parliament, Bundesrat, other ministries and numerous representative offices of the Länder.

The move to Stresemannstrasse gave the Federal Environment Ministry a building of its own in Berlin for the first time. Since it was established in 1986, the ministry has had a long history of provisional solutions. In Bonn, the staff were at times scattered among a dozen different buildings until they moved into the former Post Ministry on Robert Schuman Platz in 2002. Even in Berlin, following the move

A century earlier: Potsdamer Platz in 1919, seen from the north. Behind Leipziger Platz (photo left) is present-day Stresemannstrasse, formerly Königgrätzer Strasse (see map, page 24)

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Combining history with ambitious environmental objectives: the Federal Ministry for the Environment, Nature Conservation, Building and Nuclear Safety

The project

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Facts and figures

The initial situation: old building with Wall fragment in Stresemannstrasse (2005)

Building project: Stresemannstrasse 128-130 Owner: Federal Republic of Germany: Federal Ministry of Transport, Building and Urban Development (now Federal Ministry for the Environment, Nature Conservation, Building and Nuclear Safety); Federal Agency for Construction and Regional Policy Architects: Jürgen Pleuser, Enno Maass, Almut Geier

Change of ownership The new office building in Stresemannstrasse was originally planned for the Federal Ministry of Health. Following restructuring within the Federal Government and the merger of the Ministry of Health with parts of the Ministry of Labour and Social Affairs in the autumn of 2002, the Federal Environment Ministry (BMUB), occupying inadequate rented accommodation on Alexanderplatz, emerged as the ideal user. The decision about the change of ownership in Stresemannstrasse was taken just in time – the panel of judges for the architectural design competition was still meeting. This enabled the BMUB to embark on an attractive project. The old building underwent full environmental refurbishment and the new six-storey building in the heart of Berlin was the first ministry office building to be constructed to passive-house standards. The six-year construction phase was, in keeping with the history of the site, full of excitement. The green light was given in 2005, after architects Jürgen Pleuser, Enno Maass and Almut Geier had won the competition in 2002. Their design promised to create an ideal synthesis of old and new – the historic combined with impressive contemporary architecture. A major obstacle was soon encountered in the shape of a massive wartime bunker of reinforced concrete several metres thick that had to be removed – without affecting the existing building.

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The project

View of the Wall remains Remains of the Wall also bore witness in stone to the history of the site. Until reunification, the building stood in the middle of the border strip, as a lone witness to the pre-war urban development. During the construction work, the remains of the Wall were carefully removed, temporarily stored, and almost all of them later integrated into the new building on the original site. This meant that the general public had a clear view of – and access to – the concrete segments with their colourful post-reunification paintings. The segments form part of the ministry’s information and exhibition rooms – and are easily seen, even from a distance, through the expansive glass front. Architectural improvements were also made to the existing building. The sloping roof destroyed during the war was replaced, and the impressive decorative elements in the interior were painstakingly restored. As a result, the new Berlin Office is not only a model of green building, but also an organism that lives and breathes history – an attractive urban element in the city’s new centre.

Size of site: 5,389 square metres Floor area: 16,630 square metres Principal useful area: 8,483 square metres Workplaces: 305 Competition: September 2002 Start of construction: May 2005 Occupied: June 2011 Completion: Autumn 2011 Construction costsy: 67.4 million EUR Environmental technology and sustainability concept: Dr. Uwe Römmling Support, structure planning: Wetzel & von Seht, Hamburg/Berlin Project steering: Arcadis, Darmstadt Building services engineering: Hyder Consulting, Berlin; GT-Plan, Berlin Lighting planning: Licht Kunst Licht, Bonn/Berlin Constructional physics, fire safety: Müller-BBM, Berlin Internal acoustics: Hans-Peter Tennhardt, Berlin Subsoil assessment: GuD Consult, Berlin Building survey: Rek, Schwenk, Partner, Berlin Blower-door measurements: Dr. Manfred Flohrer, Berlin Passive-house certificate: ZEBAU – Zentrum für Energie, Bauen, Architektur und Umwelt, Hamburg Structural engineers: Zoega, Berlin Environmental architectural consultation: Gesellschaft für ökologische Bautechnik, Berlin

The urban context: model with Stresemannstrasse in the foreground

Performance specifications: Berliner Energieagentur (Berlin Energy Agency) Awards: European Architecture Prize Energy + Architecture (2012); BDA Prize Berlin, Public Award (2012)

The project

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View of the east front: the triple-glazed windows have oak frames, fully in keeping with the historical model while meeting the demands of sustainability

Performance specifications The 40-page specifications focus on the life-cycle assessment of the building, its cost and the well-being of its users. The recommendations relate to efficient use of energy and matematerials used – “Preference is basically to be given to renewable resources.” The recommendations also give advice on construcconstruction – “When planning storey heights, care should be taken not to take premature decisions about synthetic resin coatings and seals in underground car parks, basements or sanitary facilities.”

A sustainable model building The requirements for the construction of the new building for the Federal Environment Ministry (BMUB) on Stresemannstrasse were very ambitious, right from the start. The new Berlin Office was to set not only an example of energy management and resource consumption, but also for environmentally-friendly building materials and emissions, lighting, water and wastewater. At the same time, it was to provide the ministry personnel with healthy and comfortable office accommodation. An important basis for the planners was the Federal Government’s “Sustainable Building” guide to holistic planning. The top watchdogs for energy-saving construction were the Federal Government’s long-serving Energy Officer, Uwe Römmling, and his successor, Olaf Böttcher. After the move to Berlin as the capital, Römmling demanded uniform

Many recommendations are easy to put into practice or have already become architectural standards – “The layout of the building is to be organised to allow central supply and wastewastewater lines over short distances.” Others, however, are less easy to implement – “When awarding building contracts, perforperformance comparisons should take priority over cost comparisons.” But the environmental objective must always be balanced with engineering and economic considerations. For example, it would have been ideal to use insulating material made from renewable raw materials, but commonly used rock wool was chosen in view of its better durability, fire safety properties and much lower costs.

requirements for all federal buildings. Architects and planners now have to stay in line with his key parameters for energy consumption, heating and cooling systems. For the Federal Environment Ministry, however, the bar has now been set very much higher – a much more stringent target specification was drawn up with directives and recommendations going far beyond the usual standards for government buildings. These performance specifications, laying down targeted requirements ranging from building ecology and internal acoustics to workplace quality, became the constant companion of planners, architects and workmen (see info box).

Environment and energy 11

Monitoring: from theory to practice Creating a passive building – the great challenge One particularly ambitious goal was to achieve passive-house standards for the new part of the building. This limits heating requirements to 15 kilowatt-hours, the equivalent of one and a half litres of heating oil per square metre per year. For comparison – in existing buildings, this figure is often more than 150 kilowatt-hours or ten times the amount. In a passive house, total annual requirements of primary energy for heating, hot water, ventilation and all electricity applications together must not exceed 120 kilowatt-hours per square metre. In this case, the figure was to be as low as 100 kilowatt-hours. Great priority was placed on preventing air leaks. The aim of achieving passive-house standards proved to be a very ambitious challenge because in a tight, shady city centre like Berlin, it is impossible to achieve the solar heat input that one normally hopes for in passive houses. This made it all the more necessary to pay attention to other factors, especially good thermal insulation, airtightness and needs-oriented ventilation with highly efficient heat recovery. Great efforts were also made to minimise power requirements – e.g. for lighting, ventilation and office technology.

Ceiling panel office heating: in a passive building, this helps to save energy and ensure a comfortable interior climate

12 Environment and energy

Buildings of passive-house type are certified by experts to confirm that the targets have been met. A complex evaluation procedure of this kind was also adopted for the Federal Environment Ministry’s new Berlin Office. The reward for all these efforts was the “quality-tested passive house” certificate issued for the new building in late 2010 by Hamburg-based ZEBAU (Zentrum für Energie, Bauen, Architektur und Umwelt GmbH). They examined the planning and construction of the building and the performance data for energy demand and air quality – values that are initially theoretical, but which have to prove their worth later in everyday operation. Monitoring during the first few years of operation will show whether the figures are actually achieved. To this end, the building is equipped with an extensive measuring system that not only makes use of control parameters from the building services systems, but also uses sensors of its own. Some 350 points measure temperature, humidity, volumetric flow rates and electricity consumption. Power, heating and refrigeration circuits, switching commands and control statuses are kept under permanent observation. The measurements are analysed in a monitoring program so that the systems can be modified later as necessary. Monitoring analysis of consumption has only been possible since 2013. The analysis runs until 2015, at which point the project will be completed.


Sustainable energy management: heat, light and air Innovative approaches to supplying energy and heat to the new Federal Environment Ministry were adopted and a whole range of modern environmental technologies implemented – fuelcell and photovoltaic systems, district heating and cooling from combined heat and power generation, as well as wastewaterheat recovery. The neighbouring energy centre for Potsdamer Platz was an obvious source of energy for heating and refrigeration and it proved to be more sensible and sustainable to use this centre’s capacity rather than to build a separate combined heat and power plant. In addition to the targeted passive house standards, the performance specification listed the following targets: economic and efficient use of energy while ensuring a healthy and comfortable office climate pleasant lighting making extensive use of daylight no hot water in offices and wash-rooms normally no mechanised refrigeration power consumption not to exceed 25 kilowatt-hours per square metre per year heating energy requirements in existing building to be reduced by at least 60 per cent

In particular, reducing the heating requirements for the old building proved to be a very ambitious target in the refurbishment process. A whole bundle of measures were used to achieve this. First, there was the installation of compact thermal insulation on previously uninsulated outside walls. The main front on Stresemannstrasse caused a few headaches because the aim was to preserve its historical appearance as far as possible, but a 6-centimetre layer of rock-wool insulation underneath the external rendering eventually provided the solution. In the interests of historical monument preservation, no additional thermal insulation was allowed to be applied to the rear exterior walls, which were largely in their original condition. Special internal calcium silicate insulating panels were used here that prevent the formation of condensation which frequently occurs with internal insulation. And last but by no means least, the roof was extensively insulated with a 20-centimetre layer of rock-wool insulation and for the green roof section, with at least 30 centimetres of expanded polystyrene. In addition to the thermal insulation, triple-glazing filled with high-grade noble gas minimises heat losses through the oakframed windows. Their design kept the specialists busy testing and experimenting, as there was no suitable product on the market at that time. To increase their operating lifetime and durability, solid wood window frames are now fitted, which is by no means standard practice.

Self-produced solar power: the building’s own photovoltaic system supplies climate-friendly electricity



Photovoltaic system and solar cell Sustainable modern energy technologies are also used for energy production. To some extent, they have been installed for demonstration purposes. On the roof of the Federal Environment and Building Ministry (BMUB) is a photovoltaic system, although there was only limited room for it on the two strips each side of the glass roof. The canteen kitchen is supplied by a small fuel cell that provides a constant supply with an electrical output of one kilowatt and a thermal output of 2.2 kilowatts. The Federal Environment and Building Ministry also believes in sustainable mobility and as well as providing electric vehicles with their own green-power charging station, bicycles are also available for short errands in the city.

Attractive canopy: the roof over the northern courtyard saves energy and creates new space

A step into the underworld: heat from wastewater

Green coat Biology in the city – the Federal Environment Ministry’s new Berlin Office was given a green coat. Some 1,360 square metres of the new building’s roof were covered with a small, but ecologically function-filled habitat for butterflies and small insects. The good old stonecrop (Latin sedum), a robust succulent that can survive intensive solar radiation and long dry periods, was chosen as the main roof plant. Green roofs not only form small botanical oases, but also absorb noise, bind particulates, filter the air and provide an extra protective layer of insulation. What is more, they also store rainwater and are good for city dwellers’ souls. Robust plants: succulents growing on the roof of the new building


Some 44 kilowatts are supplied by an innovative heat-exchanger system that reaches into the sewer under Stresemannstrasse (see photo on page 21). From the wastewater there, it extracts heat that would otherwise be lost. This is a technically demanding process that needs heat exchangers made of material that stands up to the aggressive chemical environment while not obstructing the flow. It goes without saying that not very many buildings in a street can tap this source of energy.

Covered courtyards save energy A major contribution to energy saving was made by reducing the size of the building’s envelope by turning the courtyard into a covered atrium. The atrium can be heated by an under-floor heating system if needed, e.g. for special events, but in normal

everyday operation, it provides an effective climate buffer. Fresh air is supplied by an air duct routed via the underground car park ramp; the exhaust air is discharged via the roof. The north courtyard created between the old and new buildings was also roofed over. Since it is associated with open aisles that need an air temperature of at least 15 degrees even in the cold months of the year, the planners and architects had to come up with bright ideas. They now use the north courtyard to ventilate the building – fresh air is fed under pressure into the new building’s offices that are equipped with ceiling mounted heating/cooling systems. This air escapes into the courtyard via the corridors and is extracted at roof level. Effective heat exchangers recover energy from the extracted air. Continued on page 21


“We couldn’t simply turn the building around” Uwe Römmling, the Federal Government’s long-serving Energy Officer, has this to say about the ambitious environmental concept of the new BMUB building A Federal Environment Minister’s ministry building should be an example of the use of energy, resources and building materials. Have you achieved that in Stresemannstrasse? Römmling: I’m quite sure of it. We wanted to build a model house, and if you look at the result and see the whole project from a holistic environmental point of view, it really is an exemplary building – both the old and the new parts.

passive house in a city-centre location really is a complicated task. We were in the middle of the planning phase when other buildings went up around us and we realised that we had a problem with too much shade: the building would not get as much sunshine as we wanted. The alignment of the building was distinctly sub-optimal too. Instead of the desired south-facing position, we had a building that faced north – we couldn’t simply turn the building around!

What were the biggest problems you had to deal with? The new building meets the standards for a passive energy house – and building such a

And the existing building? That wasn’t easy either. The historic monument authorities had imposed strict conditions, particularly regarding the main

The environmental watchdog: Uwe Römmling

front. We met with a few surprises inside the building as well – for example, we had to get rid of an old bunker, which meant a lot of work clearing away the reinforced concrete by hand. As an experienced energy expert, you are constantly stressing that the motivation of the owner, the architect and everyone else concerned is crucial to the success of a project. You need a firm commitment on the part of the owner. There must be no capitulation if costs increase or deadlines cannot be met. Environmental concerns must prevail but can too often fall by the wayside.

Underground surprises: when excavating for the foundations of the new building, the workers had to remove soil contaminated with waste oil (see page 23)


Shade problems: high-rise buildings reduce the amount of incoming solar energy


Continued from page 17

Part of the concept: intelligent-user behaviour

How airtight is the building? Experts use the blowerdoor test to measure air exchange and leaks

In this case, the owner remained firm. The target was clear from the start and very ambitious. The owners not only stated the energy level they wanted to achieve, but also specified verification methods. A monitoring system is installed for this purpose, to measure power consumption, temperatures and other parameters during the first year of operation. Why go to all this trouble? Our experience with other buildings has shown that in practice not everything works as well as planned. Technical systems do not work perfectly and occupants and users do not behave as expected. What’s more, you have to get to know the building better – that’s what monitoring is about. Demanding an ambitious energy level on paper is one thing – but putting it into practice is the real challenge. In the Stresemannstrasse project, were you able to make use of experience from other green buildings, for example the new Federal Environment Agency building? Yes, we definitely benefited from such experience, but the Stresemannstrasse building went much further. Until then,


we had not reached passive house standards in any federal building. The Federal Environment Agency is a low-energy building that uses 30 kilowatt-hours for heating. It consumes about three litres of heating oil per square metre per year. The figure for the Federal Environment Ministry is 15 kilowatt-hours. The power consumption of the Stresemannstrasse building is much lower, too. What about the cost? Will the building’s environmental concept pay off? Quite definitely, yes. You only have to think of rising energy prices. Of course, with such a showcase building, we have to show the Federal Court of Audit and the Federal Ministry of Finance that our solutions are cost effective. The problem here is that many of the positive effects of the building are difficult to express in euros and cents. Climate, health and safety, resource conservation, pollution reduction – we have done good things in all these fields.

The old building is heated by conventional radiators and has natural ventilation via the windows without any additional technical systems. The only exceptions are the minister’s air-conditioned rooms and the large roof-level meeting room, which needs a higher rate of air change. To limit heat loss through open windows, the ministry’s employees are called upon to show environmentally aware behaviour. Individual ventilation is indispensable, however, because the natural air change due to leaks only replaces about one tenth of the air per hour, whereas the required rate is at least three times that figure. Installing controlled automatic ventilation in the old building would have been unreasonably expensive, especially since the spaces and shafts for the air ducts were not available.

Life-cycle assessment: using the right building materials A good energy balance is not the only thing a “sustainable” building needs. Building materials also play a crucial role. How people-friendly and eco-friendly are they, and how much energy was needed to produce them? How great is their climate damage potential? Are they easy to dispose of? These days, life-cycle assessment is a major task, because it needs to determine and weigh up the relative benefits of an increasing number of material properties. As standards and guidelines develop, construction practices are constantly being adapted to the new findings. It has long been the case that expert planners are needed to provide supporting advice for engineers and workmen. The lists of products drawn up by architects are approved by the GföB (Gesellschaft für ökologische Bautechnik), now known as Arcadis.

Energy from wastewater: a heat exchanger recovers waste heat from the combined sewer running below Stresemannstrasse


Black adhesive and waste oil The environmental refurbishment of the old building brought a number of surprises to light. It goes without saying that the demolition rubble had to be inspected before disposal as building waste. When a suspicious black adhesive was found under the old flooring screed, it proved necessary to remove the old screed entirely and dispose of it appropriately. The example of the wall surfaces illustrates how building work can take on a dynamic development of its own. In the interests of historic monument preservation, and also for financial reasons, the aim was to preserve the internal plasterwork as far as possible. However, once the new windows were installed, it turned out to be impossible to join up the plaster surfaces. Not only did this make it necessary to completely re-plaster the interior surfaces of the outside wall, but it also proved impossible to join up these surfaces to the crumbling plaster of the other walls. As a result, the other walls were plastered as well, followed by the ceilings. A similar situation confronted the workers in the corridors, where first the walls and then the vaulting had to be renewed. Chipping off the plaster revealed structural damage that also had to be repaired. All surfaces in the new and old buildings were treated with eco-friendly plaster and paints. Conflicting objectives emerged here, for example, regarding the paint to be used for the exterior front. In many respects, the desired eco-friendly waterbased paints do not match the performance of solvent-based paints, so the latter were used in this external situation because of their superior resistance to weather conditions. Preserving the fabric: nothing is more sustainable than eco-friendly preservation of what already exists. The German word “bleibt” indicates that the wall should remain standing


The new building had a few surprises in store as well. During excavation work for the foundations, the workers found con-

Creating a comfortable indoor climate: clay walls

siderable contamination of the soil due to oil and lubricants from the lift shaft of the former Fürstenhof Hotel. The water authorities were aware that pollutants were circulating in the district’s groundwater, but they did not know their origin or cause. Because the contaminated soil made it necessary to dig deeper than planned, the plans were revised and the new building was given two basement levels instead of one.

Clay walls for comfort Although the new building now went ahead as planned and without problems, the installation of the clay walls presented new challenges. Clay is a natural building material that creates a particularly pleasant indoor climate, but it is still rarely used. The most recent standards date from 1935. In most cases, clay walls are built on a wooden frame like plasterboard partitions or, as in Stresemannstrasse, with the usual metal rack, but the first panels started crumbling as they were screwed into place – the problem was finally solved by using jute inserts. Applying the wet clay plaster as a two- to three-centimetre layer was by no means a routine procedure, but finally the battle was won. Ultimately, above all the environmental and energy benefits of the building, there is one thing that counts – the people working there must feel good.


The old government quarter “In den Ministergärten” (“In the Ministerial Gardens”) is the name of the street in Berlin’s new centre that is now the home of seven representative offices of the Länder (states). The name dates back to the magnificent palace built on Wilhelmstrasse in the 18th century that housed the ministries of the state of Prussia and later those of the Empire, the Weimar Republic and the Nazi dictatorship. Its generous gardens extended as far as the zoological gardens. Initially, this was the residence of Prussian nobles and prominent members of the military hierarchy, then the quarter developed into the power centre of the Prussian state. Along Wilhelmstrasse, Leipziger Strasse and Unter den Linden, the institutions of the Prussian state ran like a string of pearls – from the Foreign, Justice and War Ministries to the Ministry of Cultural Affairs. The ensemble also included the Prussian Ministry of Agriculture, Domains and Forestry that stood on Leipziger Platz. The rear part of this office building on presentday Stresemannstrasse has now been converted and extended to create the Berlin Office of the Federal Environment and Building Ministry.

Potsdamer Platz around 1900: urban life in the centre of the new metropolis

The old government quarter: this map, dating from 1906, shows in red the great concentration of public buildings in the region of Wilhelmstrasse and Potsdamer Platz

History 25

The Reichstag – massive splendour After 1871, the Prussian government quarter became the centre of power of the German Reich, which set out to demonstrate continuity by establishing its institutions at the heart of the former Prussian state. As early as 1872, the Reich Chancellery took shape in Wilhelmstrasse and ten years later, the architect and university lecturer Paul Wallot, designed the Reichstag – a colossal solution of great magnificence in keeping with the euphoria of the time. The other authorities

From “Führer balcony” to new Reich Chancellery – the Nazi state takes up residence remained clustered around Wilhelmstrasse and Leipziger Strasse. Where representative buildings were concerned, the German Reich saw itself competing with Paris. Initially taking the early Florentine renaissance period as a model, officials later turned to the Italian High Renaissance and finally arrived at “Wilhelminismus”, which left nothing to be desired in terms of opulence and Baroque monumentality.

During the Nazi period, Hitler and his architect Albert Speer planned an outsize government centre extending from the Spreebogen to Tempelhof Airport. But first of all, Hitler demonstrated his presence in the established quarter to the west of Friedrichstadt. Speer extended the Reich Chancellery and gave it a “Führer balcony”. For the 1936 Olympic Games, the Wilhelmplatz below the balcony was used for parading. On the north side of Wilhelmplatz, the Reich Ministry of Public Enlightenment and Propaganda with its grey stone front became the office of Joseph Goebbels. Finally, in 1937–38, Speer implemented Hitler’s ideas for a new Reich Chancellery on Vossstrasse, integrating the Chancellor’s office and the Palais Borsig on Wilhelmplatz. This colossal building was more than 400 metres long, an architectural statement of National Socialist power.

Monumental impact: outraged by the modern steel dome of the Reichstag, Kaiser Wilhelm II never set foot in the building

26 History

Stresemannstrasse in 1939: on the left, the Hotel Fürstenhof; behind it, the former Prussian Ministry of Agriculture, and on the right, with the dome, the entertainment centre “Haus Vaterland”

Dust and ashes – major wartime losses

GDR government uses surviving buildings

By this time, the government quarter around Wilhelmstrasse had reached its maximum concentration and density, but little of this density survived the wartime bombing. Large areas of the western part of Friedrichstadt in particular were destroyed and all that was left of nearly all the ministries was dust and ashes. With few exceptions, the entire historic area to the west of Wilhelmstrasse between Pariser Platz and Leipziger Platz was wiped out. In later years, the GDR used areas of the old government quarter for the Berlin Wall, border fortifications and to build prefab multi-storey residential blocks.

Owing to the loss of buildings during the war, the govern ment authorities of the GDR were spread over the entire city centre. The few buildings on Wilhelmstrasse that were spared by the bombs continued to be used. For example, the surviving Prussian Ministry of Cultural Affairs was also used for this purpose. The building of the former Nazi Ministry of Propaganda was used in GDR times by the Ministry of Media Policy and the Reich Ministry of Aviation became the “House of the Ministries”, the centre of government power.

History 27

The Federal Government in the old government quarter Today, after an interim period as the seat of the Treuhand Agency, the Detlev Rohwedder building is used by the Federal Ministry of Finance. Two more Federal Government ministries are also to be found in this district today – the Federal Ministry of Food and Agriculture moved into the refurbished building at Wilhelmstrasse 54 while the Federal Ministry of Labour and Social Affairs is based in the former Reich Ministry of Propaganda in Wilhelmstrasse. The Ministry for the Environment, Nature Conservation, Building and Nuclear Safety is now established on Stresemannstrasse as another federal ministry in the former government quarter. Its neighbours are the Bundesrat, the Berlin Chamber of Deputies and the representative offices of the federal states.

Moving fate of a building The turbulent changes that the government quarter experienced in more than a century did not stop at the doors of the ministry’s building on Stresemannstrasse. Prussia’s Ministry of Agriculture had also long been suffering from an acute shortage of space. In the old office on Leipziger Platz, the “corridors were narrow and often dark, and the offices inadequate” and “the condition of the building was so poor that maintenance costs were high”, according to the periodical “Zeitschrift für Bauwesen”.

28 History

Front view: the old Prussian Ministry of Agriculture (1936)

This intolerable situation finally prompted the Minister of Finance to promise an extension on Königgrätzer Strasse – as Stresemannstrasse was known at that time. It was not until 1929 that the street was named after Gustav Stresemann, the former Chancellor of the Weimar Republic. In 1935, the National Socialists renamed it Saarlandstrasse, and from 1948 onwards, it was again called Stresemannstrasse.

Kaiser criticises architect In 1902, work started on the new Prussian building on present-day Stresemannstrasse, but owing to budgetary problems, the first brick was not laid until a full ten years later in the summer of 1913. Kaiser Wilhelm II was well known for exerting influence on the design of public buildings, demanding to see the drawings and frequently wielding a pen himself. “Very ugly” was the Kaiser’s damning verdict on the architecture in this case. As a result, architect von Salzwedel was posted to Potsdam and the task of planning was assigned to senior planning surveyor Hans Grube, who had already designed the new opera house to the Kaiser’s satisfaction. On the outbreak of the First World War in 1914, construction was in full swing. After various delays, the building came into service in September 1916 and the last of the shops on the ground floor was let in October 1917. In the end, the front was seamlessly integrated into the street with the neighbouring Hotel Fürstenhof, without asserting any special presence to the ministry building.

History 29

An open house

In the no-man’s-land of the divided city

Compared with present-day ministries and their strict security measures, the offices of those days were open houses. For example, the ministry building had its own perfectly normal entrance – only a grating separated the open vestibule from the street; the staircase foyer was reached via a porch and a small vestibule. The main staircase of almost baroque proportions boasted finely profiled ceilings, binding beams and sturdy pillars.

In the divided city of Berlin, the building suddenly found itself in the border strip. Like most other buildings that had to come down to ensure a clear line of fire, the neighbouring buildings were removed. From this time on, the former ministry stood on its own in the no-man’s-land as a lone witness to the pre-war buildings.

After the founding of the GDR: headquarters of the Consumer Cooperatives

The floor plan shows an efficient modern row of offices. The courtyard was full of greenery and was kept free of delivery traffic. Deliveries were made via the side yard adjoining the Hotel Fürstenhof. Four upper storeys were almost completely filled by 190 offices. There were two small meeting rooms on the third floor; the main conference room was in the transverse building at the rear of the site. The attic housed a laundry with ironing room and a drying room for the ministry’s laundry and there was a roof terrace “for dusting off files”. Even though the entrance and staircase radiated a certain solemnity and grandeur, they did not compare with the magnificence of Berlin’s palatial courts of law. According to an engineer’s report dating from 1948, the building was worth some 2.1 million reichsmark.

First conversion projects and wartime destruction One of the first structural alterations to Stresemannstrasse 128 was the installation of marble floors in the lobby and the representative entrance hall in the thirties. Various pillars were removed for better access.

30 History

The erection of the Berlin Wall in Stresemannstrasse gave rise to a curious situation, because the front of the building became part of the Wall. The windows were therefore bricked up and the

main entrance closed; the new entrance was now on the east side. Two watchtowers were installed on the roof to provide a strategic view of the border fortifications. Following reunification, the building underwent a first refurbishment in 1991; a shallow gable was placed on the centre of the transverse building. It was in this form that the architects found it when they set about planning the conversion work for the Federal Environment Ministry.

In the forties, the biggest intervention was the construction of an air-raid shelter on the ground floor. The massive concrete structure, three metres high, allowed no more than a very low corridor for access. The wartime damage was relatively light. A bomb strike destroyed three rows of windows in the front of the building; the external walls and corridor ceilings were damaged, and a mortar strike destroyed the conference room in the transverse building. However, cracks were caused by mortar and bomb fragments, vibration and shock waves. Plaster fell off the walls, all window panes were broken, doors damaged and the roof stripped off. Three years of wind and weather continued the process of destruction, while thieves removed parts of the electrical installation. In 1948, the Association of German Consumer Cooperatives took on the task of refurbishing the building with a view to using it as their administrative headquarters. The large roof structure was replaced by a flat concrete roof covered with roofing felt. Refurbishing the façades also resulted in serious losses – the natural stone was chipped off down to the wall footing. The façades were surfaced with a plain scratchwork plaster.

Five years before its fall: the Berlin Wall – behind it on the left, is the old Stresemannstrasse building with the Hinterland Wall

History 31

Historic meets modern: a vertical gap separates the old and new fronts of the Federal Environment Ministry

Compact composition: overall view from Stresemannstrasse

Exciting interplay of old and new The new office building of the Federal Environment and Building Ministry in Berlin was to live up to all public expectations by meeting outstandingly high sustainability standards. However, the attractive location on Potsdamer Platz, the fringe of Berlin’s lively new centre, also presented an architectural challenge. The task was to integrate the building of the ministry in the urban context and observe the rules of typical Berlin architecture – building right up to the edge of the available site area; an eaves height of 22 metres and a stone façade with recessed windows (“grid façade”).

The old building was typical of Berlin’s architectural tradition. The new building not only observed these rules, but gave them an impressive interpretation – for example, in the rhythmic window pattern of the new entrance hall. Although the new building is unmistakably modern, together with the striking old building, it forms an exciting combination that fits harmoniously into the city setting. As a result, the new building – despite the restraint appropriate to a ministry building – can make its presence felt in the context of major international architecture.

Architecture 33

Historical horizons of the building site What this location experienced during the 20th century was the typical fate of Berlin – splendour, glamour, destruction, decline, neglect and, in the intervening periods, a range of uses. The old Wilhelminian Ministry of Agriculture with its neo-renaissance front, vertically sectioned decorative classical elements and avant-corps (risalits) represented the city and metropolitan flair. On the ground floor, with the large granite blocks, the shallow-vaulted openings created space for shops. The area between the bustling Anhalt station and the entertainment centre “Haus Vaterland” near Potsdamer Platz was full of vibrant city life. The Second World War and the partition of Berlin seemed to have destroyed this for ever. In the end, the building became derelict as part of the Wall in the middle of no-man’s-land.

Art vagabonds in no-man’s-land This no-man’s-land along the Wall border strip also determined the character of the urban area of southern Friedrichstadt, in the Berlin district of Kreuzberg. The barren waste of an inner-city fringe area still dominates Stresemannstrasse today, despite the brilliant setting of the new Potsdamer Platz. The expectation with regard to a new building for the Federal Environment Ministry was that this part of the city would regain its metropolitan look.

The Berlin Wall fragment in 2005: integrated in the building and accessible to the public

34 Architecture

The fall of the Wall, when the no-man’s-land began to turn into city again, marked the beginning of a spectacular, but largely forgotten interlude. Directly after reunification, the open no-man’s-land attracted action artists from all over the world. They called themselves art vagabonds and lived in small tent cities. In the late 1990s, artists painted the remains of the Wall

Bird’s-eye view of the ensemble: the loggia as a triangular entrance hall provides an impressive view of Potsdamer Platz

to protect them from demolition. The brightly sprayed Wall fragment preserved in the new building is a reminder of this.

Architects’ design contest Following the decision on 20 June 1991 to make Berlin the capital city, the search began for suitable locations for parliament and government. One of the available sites was

Stresemannstrasse 128-130. An architects’ design contest was announced – with clear requirements – on the one hand, observance of the Berlin urban development plan and on the other, the integration of two protected objects – namely the former Ministry of Agriculture and the Wall fragment painted with various designs. This fragment of the Wall was to remain accessible for people to experience in the entrance area, but without “going over the top” from a design point of view. Altogether, 125 teams of architects took part.

Architecture 35

outside the security area and is freely accessible. Here is the information point and a small lecture theatre.

View of inner courtyard: the historical façades were largely preserved

The winning design The panel of judges met in October 2002 , chaired by architect Professor Rebecca Chestnutt. The first prize of 25,000 EUR went to Jürgen Pleuser, Enno Maass and Almut Geier from Berlin. The award-winning design was a clear candidate from the outset because it brought together an exciting ensemble – Wall fragment and old and new buildings – creating a stimulating dialogue between past and present, and also the internal and external structure. Speaking of an “interaction of fragments”, architect Jürgen Pleuser recalls the historical discontinuities that are characteristic of this site. The historic appearance of the old building is restored with its sloping roof and the rounded dormers. The historic building not only regains its inner structure, but also has a dominant overall impact.

The old building is clearly separated from the new building by a glazed vertical gap. On the corner facing Potsdamer Platz and along Erna-Berger-Strasse, it stands out clearly in presentday architectural language as an office building in its own right. The fragment of the Berlin Wall at this point can be seen in a separate, building-high exhibition room, glazed on the street side.

Two covered courtyards create new space The service entrance with vehicle security is also accommodated in the new building. Official cars enter the building from Erna-Berger-Strasse and leave in the direction of Gartenhof. With its striking glass roof, the north courtyard, created by building along the edge of the site between the old and new buildings, has similar interior functions to the large courtyard of the old building.

The visitors’ centre

The outside walls of the new building are of yellowish concrete blocks reminiscent of sandstone. The grouping of the tall, narrow rectangular windows does not follow any set pattern. This is a characteristic of present-day architecture that will make it possible to date the building in the future. An open loggia on the top floor at the corner of the building provides a magnificent view of Potsdamer Platz.

The ground floor once again houses public functions. On the left, next to the exhibition room in the new building, a canteen welcomes guests. To the right of the main portal, which is now used once again as the main entrance to the ensemble, the ministry’s visitors’ centre opens its doors

Despite all security requirements, the character of this government building is not unfriendly. Immediately adjacent to the lively Potsdamer Platz, the architect has succeeded in creating a building that is as open as possible in the ground-floor zone that faces the city and integrates the ministry into the life of Berlin. Continued on page 40

36 Architecture

“The building is unmistakable” Architect Jürgen Pleuser talks about the history and surroundings of Potsdamer Platz and the task of bring old and new together Mr Pleuser, what was the biggest challenge of this project apart from the environmental standards? Pleuser: It consisted in composing a coherent, functioning whole from a large number of old and new structural elements. First there was the old building, a historic monument that had to be restored stone by stone and the new building, certified as a passive house. The fragments of the Berlin Wall also had to be included, not to mention the new rooflevel storey with numerous offices. And last, but not least, two large halls of very

different architectural character that were created by covering the open courtyards with a glass roof. Is this integration a harmonious success? The various elements form an exciting, intertwined ensemble. A particularly striking feature is the enriching change of scale from small offices, the individual offices for the staff of more than 300, and the building-high, open-plan rooms bathed in light that act as points of reference – making, in architectural terms, an unusual spatial quality inside the building.

Guided tour with guests: Architect Jürgen Pleuser leads a guided tour of the building during the construction work

How important do you consider the history behind the old building? Right from the start, I have vigorously supported the Federal Environment Ministry’s aim of demonstrating here in an exemplary fashion how you can make sparing use of resources and energy. This basic attitude leads directly to considering how to rescue as much as possible of the fabric of the old building. What could be more sustainable than re-using existing material by making cautious repairs? The scale and materiality of the old building were also an important starting point for designing the elements of the new building. For example, the ge-

Roofed over from the gable: the rear of the old building

Interview 37

nerous ceiling heights and room sizes by present-day standards, the wide corridors, and the open staircases of the old building set the scale for the new building. Presumably the wartime damage was also a challenge? Only makeshift repairs had been made to the destruction in the old building after the war. The main front, in particular with its large sills and pilasters and the sandstone base, were severely damaged. Style elements of this kind, which recalled Wilhelminian times and Prussian dominance, were ideologically undesirable in the GDR. They therefore decided to sand the entire front and prevent its restoration for ever by inserting new windows in the façade. We got to grips with the results and decided to document the “undecoration” and make it into a design feature of the main front. Where there were once broken-off sandstone elements, we created recesses in the rendering of the façade.

expect that from technically sound architecture. Another remarkable feature is the interaction between existing and newly added elements and the contribution this makes to the ensemble. You can see this, for example, in the remains of the Hinterland Wall standing on the middle of the site. One might regard the remains as an obstacle to a sensible design of the new building, but this very conflict gave rise to an idea that influenced the character of the ensemble, namely to “give the Wall space”. What is your attitude to the representative character of government buildings? This building makes a restrained contribution to the cityscape, without making a great fuss, but there are enough architectural clues as to its special standing as a public building. It is unmistakable and symbolic and in the future, its appearance will stand for the ministry and its mission.

Was your design influenced by the city setting and its historic background? It goes without saying that the ensemble of buildings respects the urban framework and is in keeping with the scale of the surrounding buildings – you can Modern architecture: the playful façade

38 Interview

Creating space: the “bridge” between the old and new building above the Wall fragment

Architecture 39

Continued from page 36

Historic decorative elements: reconstructed double pillars with Ionic capitals in the entrance hall

Preservation of historic monuments: interpretation and original It was clear from the start that the historic monument authorities would have no problems with Jürgen Pleuser’s design. On the other hand, nobody wanted to simply turn back the clock and conjure up an unchanged version of the building from imperial times. It was necessary to take account of the historical development – from the original Wilhelminian structure of the Prussian Ministry of Agriculture right up to the interventions during GDR times. The architect and the historic monument authorities were agreed that structural elements and details of the original period should be preserved and that the new building should be in line with the character of the old building. Original elements most closely

40 Architecture

approaching the original condition were found in the courtyard façades and in the rear wings of the building. The historic lines of the roof were also restored. The external cladding of the main front had to be completely renewed, which raised the question of which period the new surface should reflect. The possibility of restoring the original façade of 1919, which had been destroyed in 1951, was rejected on principle and also for financial reasons. But as a tribute to history, the former structure of the quarry blocks was reproduced in the new rendering as a negative relief in the same colour, with a slight shade effect that recall former features, such as the pilasters on the outside wall.

Artistically wrought: staircase railings

Architecture 41

The charm of the old: view of the historic staircase

Curtain up for shape and colour

The historic hall Inside some parts of the building, there are historic design elements that have been painstakingly renovated and restored. This begins in the small vestibule with the stucco vaulting. In the adjoining large hall, the historic appearance has been largely recaptured. Ionic double columns, classic door portals and the stucco ceiling were restored, damage repaired and missing elements added. The new lighting incorporated in the coffered ceiling creates an almost festive look. The two main staircases and two of the ancillary staircases with their artistic wrought-iron railings were also restored in line with historic monument preservation criteria.

Venerable rounded arch: reconstruction of the original vault shape

The staircases and corridors regained their old vaulted form. The jambs of the office doors throughout the building, originally of artificial stone, were restored by stonemasons. None of the wall and floor surfaces were in their original state, so

their look was tailored to their historic appearance. As a result, the interior of the building can once again be experienced as a highly attractive cultural monument.

42 Architecture

The public sector has a special cultural responsibility for its buildings. This includes “art in architecture”, which is an integral part of the owner’s construction task and responsibility. As part of an art concept for the Federal Environment Ministry’s new Berlin Office, two “Art in Architecture” competitions and a “Young Art” buying campaign were held. The foyer on the fifth floor of the old building, a room 60-metres long and bathed in light under the steep sloping

roof, is one of the sites designated for a work of art. This location was selected because it forms the approach to the large meeting room where the ministry’s most important meetings are held. The wall leading to this meeting room was to be designed by participating artists. This competition was won by Düsseldorf artist Katharina Grosse with a 140-square-metre mural, sprayed in several layers. It creates a storm of colours sweeping across the wall (see pages 44-45).

Art in architecture 43

Creating space: with her mural (left and right), art professor Katharina Grosse won the competition for the foyer below the roof of the old building

The well-known artist and professor of painting, whose works have been shown in numerous exhibitions at home and abroad, writes this of her design – “Parts of the doors are integrated in the work. On the one hand, this strengthens the connection between architecture and painting, while on the other, it enables the visitor to experience the painting as a surrounding phenomenon. Visitors’ impressions of the picture, architecture, space and their own movement through the corridor blend into a single experience.” There is no point from which the work of art can be seen in its entirety. The view of the work varies with the visitor’s changing perspective, as new angles are constantly created by their starting point and direction. Art historian Katja Blomberg regards Grosse’s mural as a walk-in work of art, “which is dominated by variations in colour temperature and where transitions and contours are indefinite and offer multiple perspectives”. This frenzy of colour “thus goes beyond the two-dimensional and could also be interpreted as a landscape space or even an acoustic phenomenon”. The competition for the second site in the covered north courtyard of the building was won by internationally renowned Antony Gormley from London. He proposed suspending a cloud-like structure of metal polyhedra at half height in the air space of the courtyard, the shape of which would be

44

created by a threefold-enlarged plaster impression of a human body. The panel’s verdict was that the work of art “subtly suggests the integration of mankind in wider contexts”. Unfortunately static considerations made it impossible to realise the structure, which would have been more than seven metres long. The third part of the art concept was a buying campaign for “Young Art” to provide works of art for the walls, corridors and meeting rooms of the new building. For many years now, the Federal Environment Ministry has supported gifted young artists making the transition from education to working life. By acquiring works made in master-student and degree courses, the ministry’s art commission has gradually

built up a collection of contemporary art. For the new Berlin Office, the aim was to select works by artists who had completed their studies not more than five years previously. The public competition met with a great response: 417 entries met the formal requirements. They included graduates from almost all the German art schools and academies. Works were submitted by master students of well-known artists. After intensive discussions, the selection panel chose 57 works for purchase from 36 artists. The spectrum of artistic techniques ranged from photography, oil and acrylic painting, drawing, lithography and screen printing to material collages and other combined techniques.

Art in architecture 45

The “Young Art” works of Ariane Faller and Mateusz Budasz

Picture credits

Also purchased and presented in the new building: the “Young Art” works of Birgit Klerch (“Little Escapes”, left), Nina Hohberger (“Halle/Carl-RobertStrasse”, below right) and Moritz Frei (“Untitled”, excerpt, page 43)

46 Art in architecture

Cover: BMUB, Florian Profitlich / p. 4: BMUB, Jürgen Schulz / p. 5: Federal Government / Sandra Steins / p. 6: BMUB, Florian Profitlich / p. 7: bpk, Luftbild Berlin GmbH / p. 8: BMUB, Florian Profitlich / p. 9: Senatsverwaltung für Stadtentwicklung Berlin, Inge Johanna Bergner / p. 10: BMUB, Florian Profitlich / p. 12–13: BMUB, Florian Profitlich / p. 15: BMUB, Florian Profitlich / p. 16: BMUB, Florian Profitlich / p. 17: BMUB, Florian Profitlich / p. 18: BMUB, Florian Profitlich / p. 19: BMUB, Florian Profitlich (both) / p. 20: BMUB, Florian Profitlich / p. 21: BMUB, Florian Profitlich / p. 22: BMUB, Florian Profitlich / p. 23: BMUB, Florian Profitlich / p. 24: Landesarchiv Berlin, Cartographic Department / p. 25: Ullstein Bild, Roger Viollet / p. 26: akg Images / p. 27: Ullstein Bild, Sobotta / p. 28–29: Landesarchiv Berlin / p. 30 Zentralkonsum eG / p. 31: Ullstein Bild, Sobotta / p. 32: BBR, Ursula Böhmer / p. 33: Jürgen Pleuser / p. 34: BMUB, Florian Profitlich / p. 35: BBR, Ursula Böhmer / p. 36: BMUB, Florian Profitlich / p. 37: BMUB, Florian Profitlich (both) / p. 38: BMUB, Florian Profitlich / p. 39: BBR, Ursula Böhmer / p. 40: BMUB, Florian Profitlich / p. 41: BMUB, Florian Profitlich / p. 42: BMUB, Florian Profitlich (both) / p. 43: BBR, Moritz Frei / p. 44: BBR, Ursula Böhmer / p. 45: BBR, Ursula Böhmer (left); BMUB, Florian Profitlich (right) / p. 46: BBR, Birgit Klerch (left); Ariane Faller & Mateusz Budasz (above right); BBR, Nina Hohberger (below right); Strip at bottom of all pages: Jürgen Pleuser

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