Colour in Mass. Concrete and Pigments

COLOUr IN MASS CONCRETE AND PIGMENTS Ciudad de la Justicia OF Barcelona David Chipperfield Architects & b720 Fermín Vázquez Arquitectos

TABLe of CONTents 4

1. FACE TO FACE Conversation between David Chipperfield and Fermín Vázquez

15

2. THE PROJECT Description and graphic documentation

51

3. EXECUTION

117

3.1 The structure as façade or the façade as structure 3.2 Material composition 3.3 Concrete and colour 3.4 Moulds and configurations 3.5 Execution and quality of finish 3.6 Energy and environment

127

4. PIGMENTS FOR CONCRETE

53 65 79 91 99

Technical appendix 142

5. RELEVANT DATA

144

CREDITS

1.

FACE TO FACE

This meeting took place in Barcelona on the occasion of the award of the 2011 Mies van der Rohe Prize. Two years have passed since the end of the construction work and the Ciudad de la Justicia has ceased to be perceived as a singular work, and has become, instead, an integral part of a group of buildings in a landscape that is familiar to the citizens.

The circumstances of the project and its execution can now be considered with the perspective provided by the passage of time.

4

CONVERSATION BETWEEN DAVID CHIPPERFIELD AND FERMÍN VÁZQUEZ

FV: I should like us to talk about the reasons for the massive character of the buildings of the Barcelona Ciudad de la Justicia and the reasons for the colour applied in their mass.

DC: Maybe we should ask, retrospectively, did we achieve anything? Was it something… was it a good idea to do it like that?

Because I must say, actually, I think it’s one of the qualities, in the end it became one of the most positive qualities of the project.

FV: I’m convinced it was a good choice: one of the ideas that were not there in the beginning, and then came out of a bit of anxiety.

DC: I think it very much came out of anxiety to consider how to guarantee some substance and some physical quality to the project, and I suppose an anxiety that started with the competition proposal of a glass building because we thought that a glass project might suggest, in a sort of rhetorical way, transparency.

2.

THE PROJECT

Description and graphic documentation

The new legal departments of the cities of Barcelona and L’Hospitalet de Llobregat used to be spread out among 17 buildings, divided between the two cities, which caused a number of practical problems both for their users and for their employees. The unification of all of them in a new Ciudad de la Justicia (City of Justice) redounds to greater efficiency and allows for the adaptation of the working areas to the continual transformations in the legislative body.

It is situated on the boundary between the two cities, on land previously occupied by military barracks, next to the Gran Vía – one of the main roads leading to the centre of Barcelona – and next to the Avenida del Carrilet, an artery that leads to the centre of the city of L’Hospitalet.

The insertion of 240,000 square metres of built area into a relatively small space, and in a part of the city which lacks clear urban references, is resolved by the fragmentation of the programme into nine prismatic blocks of different colours and sizes which are arranged with a fair degree of compositional freedom, avoiding a rigid orthogonal pattern.

Between the buildings, a large public square has been created, which connects with the complex’s two principal access roads. Four buildings are grouped around an atrium: the Examining Magistrates’ Court, the Family Court, the Criminal Court, the Court of First Instance with the Public Prosecutor’s Office and the Juvenile

16

Court. Inside, they are arranged to allow for the movement of four different categories of user: the general public, officials, judges and prisoners.

A second group consists of a series of buildings, to some extent autonomous, and which have more varied uses. Two of them incorporate a group of judicial rooms (Building G, or the Institute of Legal Medicine) and Building H (Court of L’Hospitalet de Llobregat). Buildings J and D are reserved for uses which are Auxiliary and Complementary to the judicial activity, while Building I is for complementary social housing purposes.

The atrium becomes the main public and connecting area in the complex. With only four different storeys, it acts as a distributing path and an access filter for the judicial rooms, and also organizes the entrances to the Ciudad de la Justicia, at the same time providing them with a representative and relevant area which is indispensable in a project of this kind.

The institutional representation of justice and the problem of the project’s enormous size are reflected in a structural façade of concrete, coloured in situ, and created by means of the systematic repetition of identical window which provide luminosity and flexibility to the interior spaces.

The monolithic character of the buildings confers serenity on the judicial function and proceedings, and reflects at the same time the conclusiveness of the events occurring inside the courts.

18

32

34

Ground floor Courts Building A

Floor plan type Offices Building A

South Elevation

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3.

EXECUTION

3.1 The structure as faรงade or the faรงade as structure 3.2 Material composition 3.3 Concrete and colour 3.4 Moulds and configurations 3.5 Execution and quality of finish 3.6 Energy and environment

52

3.1.

The structure as façade or the façade as structure

The façade of the Ciudad de la Justicia was conceived in its initial competition stage as a structural grid wrapped in an enclosure of emphatic and uniform expression, and using one single material: a double skin of silkscreened glass with different colour treatments for each of the buildings in the group.

The project evolved towards a solution which maintained the attributes of simplicity, regularity and colour, but in a form that was simpler and more economical, efficient and coherent, in which enclosure and support were united in one single architectural element: a resistant diaphragm of constant thickness, composed of a grid of elements of reinforced concrete and holes of identical size. The façade was formed by the framework.

The building is supported by the façade.

To the transparency of the glazed façade are added the virtues of the massive nature of the wall supporting the concrete façade. The narrowness and depth of the gaps afford protection at the same time as they maintain visual amplitude from inside. The hidden position of the window frames reduces the expression of the façade to two materials: concrete and glass. A simple interior backing board completes the technical features of the enclosure.

Studies of cladded façades Other alternatives, which contrast with the proposal of exposed concrete, consist of the superimposition of various kinds of cladding which dissociate the visual determinants from the resistant ones. Using panels of glazed steel sheeting, it would be possible to obtain a wide range of colours with an attractive finish. A second option would involve a metallic mesh covering that would introduce variety into the appearance of the structure and recover that visual depth which was characteristic of the double skin of the façade proposed in the competition version. Their disadvantages are their higher cost, lower durability and a less impressive image than the ‘monolithic’ façade.

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Top: study of façade with stainless steel mesh cladding.

Bottom: study of façade with facing of glazed steel cladding.

Floor, elevation and cross-section.

Final version In the Implementation Plan, there is a return to the original intention of using the framework’s own material as the only finish, albeit with considerably simplified solutions.

The geometry of the pillars becomes rectangular, without flares, forming a homogenous grid of bars and gaps 60cm in width. The external skin of glass disappears, and the depth of the façade’s wall and even its shade gain in importance. A protective rail, together with the slightly delayed dropping of the upper lintel, blends with and embellishes the insides of the gaps. The slender sheet of concrete hides and protects the aluminium window framing to form a collection of spaces through which the reflections of the sky and the city stand out clearly.

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3 7 1

5 6 8 4 2 10

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9 10

Final version. Floor, elevation and cross-section.

1 2 3 4 5

Façade of self-compacting structural concrete, mass coloured, executed in situ.

Floor of concrete slabs.

Anodized aluminium window profile.

Anodized aluminium trimming Insulating glass (6/12/6) with low-emission and solar control treatment

6 7 8 9 10 11

Parapet of colourless, laminated glass (6+6) Suspended ceiling of lacquered, microperforated aluminium sheeting Raised acces floor Plasterboard dry lining Rockwool insulation Interior screen for light and visual control

Quality control procedures The occurrence of occasional incidents during the manufacture and use of concrete can adversely affect the sequence and the pace of execution of the work. In order to avoid arguments, agreement has been reached on control procedures which will guarantee viable, correct and uniform properties in the different batches supplied. Thus, parameters have been fixed for the review of the initial environmental conditions and of all the partial fabrication processes. The final result is validated by means of the slump-flow test.

CONTROL OF THE MIXER LORRY Lorry assigned according to colour and destination Keep the inside moist State of cleanliness

ENVIRONMENTAL VARIABLES CONTROL T and environmental humidity T and fine aggregate humidity

CONTROL OF DOSAGE Record of weighings according to dosage ( margin of error according to EHE) Control of volume of water and additives

FORMULATION OF THE DOSAGE Content of additives and water adjusted for seasonal variations in temperature and humidity (see dosage pattern)

COLOURING ADDITION 5Kg/m3 of colouring

MIXTURE CONTROL 1st PHASE (60% water) Mixing time first phase 2 min/m3 ADDITION OF 40% of remaining water through entrance 2 Record of added volume

ADDITIONAL CONTROL AND RECORD

MIXTURE CONTROL 2nd PHASE Mixing time first phase 1min/m3

MIXTURE CONTROL 2nd PHASE Mixing time first phase 1min/m3

CONTROL OF CONSISTENCY Slump-flow average

CONTROL OF CONSISTENCY Slump-flow average

NO D>75

55 > D >75

NO D<55

DOSAGE CORRECTION Addition of ‘Superfluidicanta’ (+10 L/m3) Addition of water (10 L/m3)

YES

55 > D >75 YES

NO

REJECTION OF THE LORRY

APPROVAL AND DESPATCH TO THE BUILDING SITE

Manufacture control for self-compacting concrete coloured in mass for façades

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Sequence of execution and position of the joints At the planning stage, a differentiated sequence of execution was considered for pillars and beams, with the joints between sections being aligned with the ends of the spaces. The use of special, comb-shaped moulds changes the rules of the game.

The joints between the plates of the same pieces of formwork are almost unnoticeable. Only the horizontal joint between pourings, one per floor, is relevant. Although the intention is to produce a continuous and smooth result, without dents or bumps, the possible changes of tone between pourings, however subtle they may be, and the slight darkening of the contact surface, can result in a series of lines that constitute part of the façade’s composition.

The logical position of this joint, from a construction point of view, is not in alignment with the space, but a minimum of approximately 7cm to the side, in order to achieve an overlap of the moulds and the part already completed, and to obtain better guarantees of geometric continuity and sealing of the moulds at the moment of start-up.

In spite of the initial reservations about the position of the horizontal joint in the façade’s composition, the tests show that its effect is only minor if good homogeneity is assured in the finish of the concrete. Moreover, this slight distortion seems to heighten the monolithic character of the façade. The openings are no longer perceived as mere emptinesses between assembled components, but as cut-outs in a massive wall with its own logic, different from that of a non-loadbearing cladding or enclosure.

Left: the configuration originally envisaged, with the joint flush with the base of the pillars.

Right: the final solution, with the joint and base out of alignment.

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Even then, owing to the complex geometry of the mould, complete watertightness is not always obtained. There some small leaks through the joints between the rubbers. Although they are not enough to cause disintegration or discolouration in the area of the loss, they can stain the lower surface. The final solution comes with the adoption of a simple complementary operation at the time of pouring: a gentle watering of the lower wall which dilutes the occasional leaks and keeps the surface clean.

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Moulding of the window-sill, and bubbles When it was agreed that there could be a discrepancy between the different sections of execution and the level of the window ledge, the problem arose of how to give a correct finish to the lower part of the spaces. The idea is to keep the concrete edge of the gap free of elements other than those of the wallâ&#x20AC;&#x2122;s own material.

The horizontal concrete surfaces can be worked easily if they correspond to the open part of the mould. But they are not like that on this occasion because the upper level of filling is a few centimetres above the level of the ledges, and selfcompacting concrete has a liquid consistency which necessitates the closing and moulding of the window sill as well. In addition to the complexity that this adds to the mould, it also involves a new problem for the finish: the possible presence of ugly bubbles of air which are trapped and squashed under the horizontal closure.

To allow the trapped air to escape, and thus avoid this effect, small perforations are made in the closing plates. During the pouring, the surface of the mould is struck with a rubber mallet to help eliminate all the bubbles that could have remained sticking to the surfaces of the plates, especially in the upper part. Only occasionally do some bubbles remain in the highest part of the flashing, which corresponds to the inside face of the wall. A small piece of aluminium flashing hides this area, freeing the edge of the concrete and leaving the perimeter of the opening clean.

Crowning of the faรงade wall Unlike what happens with the window ledges, at the top of the wall it is possible to work with an open mould, and to obtain a better result in the surfaces and edges without any material other than concrete.

Two substructure studs are fixed to the mould to serve as guides, to mould the edge with precision. By transferring a piece with the required shape, a slight drainage slope is introduced into the surface using the difference in level between the supporting tubes. Two additional smoothings of the still fresh concrete are performed using tools of different grain, to achieve the final surface quality.

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Care of the formworks On the floors where the work is in progress, â&#x20AC;&#x2DC;bedsâ&#x20AC;&#x2122; are provided to hold the parts and reduce the risk of their uncontrolled accumulation. In this way the preparatory work is made easier, as is the protection of the moulds.

In order to avoid staining the surface of the concrete, a colourless release agent of vegetable origin is carefully and regularly spread over the entire surface of the mould. Excess liquid can otherwise accumulate by gravity in the lower areas, creating very obvious changes in tone.

The procedure adopted consists of an initial cleaning, with a metal spatula, of all the dry remains from previous uses. Then, a first coat of stripping emulsion is brushed on, and is later removed to eliminate the accumulated dirt. Afterwards, a second coat is applied. Finally, the excess liquid is removed using a rubber spatula until only a fine film of release agent emulsion remains, clean and sufficient to ensure correct removal from the moulds without affecting the final quality of the surface.

4.

PIGMENTS FOR COLORING CONCRETE TECHNICAL ANNEX

This technical annex aims to provide practical information to the designer for the prescription and proper use of pigments for concrete.

The information described below is based on the experience of the “Competence Center Construction” in Uerdingen LANXESS Deutschland GmbH (Germany).

All the data, images and graphics have been produced with Bayferrox® and Colortherm® pigments used in the execution of “Ciudad de la Justicia” so we cannot be responsible for the behaviour of pigments from other sources.

The central task of architecture, which is defined here in the broadest sense as the interaction of people with constructed space, is of course the systematic planning and design of buildings and structures.

The wide range of products offered by the modern construction industry not only enables the architect to comply with nearly all potential requirements in terms of the construction, environment and use of a project, but also offers practically unlimited design opportunities.

A structure can be elegant and airy or rustic and ponderous. In addition to the structural aspects, proportions and placement of structures, their color is another design element that is of essential importance in determining whether a structure is considered aesthetically attractive or stereotypical and boring.

Color can be achieved in a number of different ways. For example, the use of white instead of gray cement gives the concrete a more pleasing appearance. A certain number of shades can be achieved by using light, dark or colored sands and aggregates, although the range of potential shades is very limited. A few additional aesthetic modifications can be achieved by post-treating the surface of the concrete (in the sense of exposing the aggregates). Paints and coatings are also frequently used. However, the paints and coatings used do not last forever, and the cost of maintaining the surfaces or repainting the building can be significant.

Compared to the coloring methods cited above, the integration of pigments into the building materials offers significant advantages. On one hand, the designer has a broad palette of colors and shades available to realize individual design ideas. On the other hand, changes in color of integrally colored building materials are very limited even over long periods, so that in contrast to paints, the color does not need to be refreshed, a fact that naturally has favorable effects on building maintenance costs.

This article describes how the coloring of building materials with pigments can influence the overall aesthetic impression of a building.

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What are pigments?

“Colorant” is the generic term for all substances that impart color. Colorants are in turn subdivided into the categories “dyes” and “pigments.”

In contrast to dyes, which are soluble in the application medium, pigments are characterized by their insolubility. Among pigments, a further, chemically oriented subdivision into inorganic and organic pigments is necessary. Fig 1 and 2.

Of the enormous variety of commercially available pigments, the ones most frequently used for the coloring of building materials are primarily inorganic pigments and in particular oxide pigments. Naturally occurring inorganic pigments have been known since prehistoric times. Evidence of the use of these natural ochre pigments can be found in, among other places, cave paintings in Southern France, Spain and North Africa that date back some 30,000 years and are as fresh today as when they were created. Until the early 20th Century, such naturally occurring pigments accounted for almost all the pigment available. Over time, both increasing demand as well as quality requirements could no longer be met by naturally occurring pigments, as a result of which the synthetic production of iron oxide pigments began approximately 85 years ago: Inorganic pigments are extremely finely ground powders that are normally shipped in sacks. Just like cement, they must be stored under conditions that guarantee they will remain absolutely dry. Pigment that has become wet readily forms clumps, a condition in which it is very difficult to mix. In contrast to cement, however, which loses some of its strength properties during prolonged storage, pigment does not lose any of its colorant properties when properly stored, even for unlimited periods of time.

Fig. 1: Synthetic iron oxide pigments

Dyes (soluble)

White pigments

Colorants

Black pigments

Colored pigments

Organic pigments

Fig. 2: Classification of colorants Relevant for the coloring of building materials

Organic pigments

inorganic pigments

Pigments (insoluble)

Effect pigments

Luminiscent pigments

The determination of the saturation range is a function of, among other things, the system parameters of the concrete. In general, however, the addition of quantities above 5% (in relation to the quantity of cement) is not necessary for high-tinting-strength pigments. With lower-quality, lower-tinting-strength pigments, however, the saturation range is reached only after the addition of significantly greater quantities of pigment. Fig 9.

The quantity of pigment required to achieve a specified shade can thereby be so large that this increase in the quantity of fines has a negative effect on the properties of the concrete.

The cement It is well known that different types of cement can also take color in different ways. Although in general, shade variations in a cement plantâ&#x20AC;&#x2122;s production seldom occur if close attention is paid to the consistent composition of the raw materials and the firing process, the shades of the cements manufactured by different manufacturers can differ very significantly from one another. Because the cement is the medium that is to be colored, the risk here is that there will be undesirable differences in the shade of the finished product.

In any case, standard practice, particularly on larger construction projects, is to always purchase the selected type of cement from the same supplier plant. In the interest of a uniform shade, however, this practice truly is essential.

White cement is of course also well suited for coloring because it can be used to achieve particularly soft pastel shades. Fig 10 and 11.

Fig. 9: Influence of the pigment concentration on the shade of the concrete

0

1

2

3

4

5

Pigment concentration (%) in relation to cement Synthetic iron oxide black Synthetic iron oxide red Synthetic iron oxide yellow

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6

7

8

Aggregates Sand and gravel, on account of their natural colors, also have an effect on the shade of the finished concrete.

Likewise, the granular composition of the sand can have an effect on the shade under certain conditions, namely when the sand contains a high proportion of fines. The higher the proportion of fines in a sand, the less pronounced the tinting strength of the pigment used. Because there is generally very little fluctuation in the composition of sand from the mine, especially in terms of the quantity of fines, there is very little risk that it will cause differences in shade, although to be on the safe side it is one more aspect that deserves consideration.

Water/cement ratio and shade of the concrete Have you ever wondered why the head on a glass of beer is white while the beer itself has a golden color?

The foam consists of lots of little air bubbles that scatter the light in the same way that white pigments do. This little digression is relevant because it explains the relationship between the shade of the concrete and its water/cement ratio.

The excess mixing water evaporates from the concrete and leaves behind cavities in the form of fine pores. These pores then act like the bubbles in the foam on a glass of beer. They scatter the incident light and thus give the concrete a brighter appearance. Therefore the higher the water/cement ratio, the lighter the color of the concrete. As the following photograph illustrates, gray concrete to which no pigment has been added obeys this law just as colored concrete does. Fig 12.

It is clear from the illustrated examples that consistency in the specified water/cement ratio is of great importance in achieving a uniform and consistent perceived color.

Fig. 10: Influence of the color of the cement on the shade of the concrete Fig. 12: Influence of the water/cement ratio on the shade of the concrete

Fig. 11: Influence of the color of aggregates on the shade of the concrete

5.

RELEVANt data FLOOR AREA RATIO 2.94 m2 of roof / m2 of floor

FLOOR AREA 53,062.62 m2

BUILDINGS AND LEVELS Building A (judicial use): 15 floors (61 metres) Building B (judicial use): 11 floors (45 metres) Building C (judicial use): 14 floors (57 metres) Building D (auxiliary and complementary use): 12 floors (49 metres) Building F (judicial use): 12 floors (49 metres) Building G ( judicial use): 7 floors (29 metres) Building H (judicial use): 8 floors (33 metres) Building I (social use for dotational facilities): 9 floors (31 metres) Building J (auxiliary and complementary use): 10 floors (41 metres) Atrium (judicial use): 4 floors (17 metres) Judicial basement: 2 underground floors Auxiliary and complementary basement: 2 underground floors Underground car park: 3 undergound floors

USES Gross area: 85,143.00 m2 (underground) + 156,376.92 m2 (over ground) = 241,519.92 m2 (total).

Judicial uses: 36,667.10 m2 (underground) + 123,573.20 m2 (over ground) = 160,240.30 m2 (total).

Auxiliary and complementary use: 2,934.72 m2 (underground) + 23,653.52 m2 (over ground) = 26,588.24 m2 (total).

Social use for dotational facilities: 9,150.20 m2 (over ground).

Parking use: 45,541.68 m2 (underground).

CONSTRUCTION Project: 2001-2006 Execution: 2004-2009 PEC: 255.268.611 euros Volume of reinforced concrete used above ground: 96,500 m3 Volume of reinforced concrete used on the faรงade: 9,500 m3 Window units: 12,000

LANDSCAPE Building footprint: 16,843.16 m2 Non-built area: 33,219.46 m2 (landscape) + 3,000 m2 (roads) = 36,219.46 m2 (total) 1,750 spaces in underground public car park

PROJECT AND CONSTRUCTION CREDITS

PUBLICATION CREDITS

International competition. Winning project David Chipperfield/David Chipperfield Architects and Fermín Vázquez/b720 Arquitectos

Original idea: b720 Arquitectos

Location: Barcelona, Spain Date of competition: 2002 Date of completion: 2008 Client: GISA, Departament de Justícia (Generalitat de Catalunya) Developer: GISA, Departament de Justícia (Generalitat de Catalunya) Main contractor: JV Ciudad de la Justicia (Fomento, Ferrovial, OHL, Comapa and Emte) Project and Construction Management: David Chipperfield Architects: Gabrielle Allam, Motohisa Arai, Tomomi Araki, Albert Arraut, Alex Bauer, Johannes Baumstark, Doreen Bernath, Roberta Buccheri, Christian Clemares, Mario Cottone, Luca Donadoni, Martin Eglin, Massimo Fenati, David Finlay, Pablo Gil, Jochen Glemser, Regina Gruber, Serena Jaff, Victoria Jessen-Pike, Melissa Johnston, Michael Krusse, Reto Liechti, Claudia Lucchini, Alessandra Maiolino, Emanuele Mattutini, Sabrina Melera-Morettini, Takayuki Nakajima, Rentaro Nishimura, Cecilia Obiol, Luca Parmeggiani, Ignacio Peydro, Andrew Phillips, Sashwin Pillai, Simon Pole, John Puttick, Oscar Rodriguez, Anika Scholin, Melanie Schubert, Jordi Sinfreu Alay, Jennifer Singer, Giuseppe Sirica, Cordula Stach, Hau Ming Tse, Patrick Ueberbacher, Laura Vega, Philippe Volpe, Giuseppe Zampieri Fermín Vázquez/b720 Arquitectos: Antonio Buendía, Francesc de Fuentes, Sonia Cruz, Guillermo Weiskal, Albert Freixes, Francisco Marques, Carlos Fragoso, Peco Mulet, Pep Avilés, Albert Arraut, Ana Caffaro, Laia Isern, Gemma Ojea, Amparo Casaní, Aurora Rebollo, Pietro Peyron, Ileana García, Jaime Luaces, Ricardo Schulz, Fernando Luna, Magdalena Ostornol, Elisabeth Farrés, Alexis Aguilar, Helia Pires, Elies Porta, María Lorentzen, Georg Kayser, Nils Becker, Eduardo Calcerrada, Mª Eugenia Codeglia, Pablo Gonzalez, Laura Lluch, Eduard Miralles, Vander Lemes, Pablo Garrido, Yolanda Roma, Nikki Ross, Gustavo Sapiña, Marco Suárez, Nuria Widmann, Raul Sánchez, Ignacio Gómez, César Bustos, James Bushell, Lucía Menéndez, Julia Nestor, Cecilia Obiol, Belen Oliver, Maximiliano Spadoni, Rebeca Spadoni, Rebeca Tristán, Rafael Vieira, María Solé, Laura Lluch, Oriol Roig, Nicolás Perfumo, Joao Cegonho, Valeria Merola, Leonardo Novelo, Tosca Salinas, Angel Corsino, Juan López, Clara Bernadás, Andrea Tamés, Marianne Verdoux, Daniel Valdés, Christian Köster, Iker Gil, Eugenia Codeglia, Javi López, Itziar Imaz, Gaelle Lauxerrois, Carme Casanovas, Katrin Baumgarten, Marco Suárez Structure: Brufau, Obiol, Moya i Associats: Agustí Obiol Jane Wernick Associates: Jane Wernick M+E engineers: Grupo JG Ingenieros Consultores: Joan Gallostra Arup: Andrew Sedgwick Lighting: Artecluminotecnia: Maurici Ginés Arup: Florence Lam, Bob Venning Quantity Surveyors: Tècnics G3: Pilar Estrada Tim Gatehouse Associates: Tim Gatehouse Façade consultants: Biosca & Botey: Xavier Ferrés Estudio Marshall: Guillermo Marshall Concrete consultants: Architectural Concrete (Juan Carlos Bolaños, Xavier Regás) Antonio Aguado de Cea Landscaping: Manuel Colominas Wirtz International: Nico Mortier, Juan Remon, Peter Wirtz Planning consultants: Estanislau Roca Arquitecte & Associats: Estanislau Roca Acoustics: Estudi Acústic H. Arau: Higini Arau Digital renderings: Carlos Pascual; David Chipperfield Architects, b720 Arquitectos, Javier Piedra, Studio Toni Yli-Suvanto Models: b720 Arquitectos, David Chipperfield Architects, Miquel Lluch, Matthew Marchbank, Vista Models Model photography: Richard Davies Site Management: Enric Peña (AT3) Project Manager: GPO/Sceps Energy Consultants: Grupo JG Ingenieros Life-Cycle Analysis: Marcel Gómez Pigments supply: Europigments S.L., Comercial Coll Vila 324 S.L.

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Editors: LANXESS Publication: Actar Graphic design & Production: ActarBirkhäuserPro Texts: Chapter 1: David Chipperfield; Fermín Vázquez Chapter 2: b720 Arquitectos Chapter 3: Pablo Garrido (b720 Arquitectos) Chapter 4: Lutz Kohnert (LANXESS) Illustrations: David Chipperfield Architects and b720 Arquitectos, unless otherwise expressly indicated Photographs: Christian Richters: p. 17, 18-19, 20-21, 22-23, 24-25, 26-27, 30-31, 32-33, 34-35, 36-37, 38-39, 40-41, 42-43, 48, 61, 62-63, 87, 98, 120-121.

David Chipperfield Architects & b720 Fermín Vázquez Arquitectos: p. 4, 56, 58, 68-69, 73, 74, 75, 77, 82-83, 84, 85, 88, 89, 95 (bottom), 97 (bottom), 102-103, 105, 106 (left), 107, 108, 109 (bottom), 111, 112.

Rafael Vargas: p. 70, 71, 78, 90, 93, 94, 95 (top), 97 (top), 104, 106 (right), 109 (top), 113, 116.

Joan Argelés: p. 64, 114-115, 122.

LANXESS: 129, 133, 134, 135, 136, 137, 138, 139, 140, 141 (top).

David Farrán fotógrafos: p. 141 (bottom), 142.

Translation: Q! estudio: Inmaculada E. Maluenda & Enrique Encabo Seguí Proofreading of the English version: CPSL Distribution: ActarBirkhäuserD Barcelona–Basel–New York www.actarbirkhauser-d.com Roca i Batlle 2 E-08023 Barcelona T +34 93 417 49 93 F +34 93 418 67 07 salesbarcelona@actarbirkhauser.com Viaduktstrasse 42 CH-4051 Basel T +41 61 5689 800 F +41 61 5689 899 salesbasel@actarbirkhauser.com 151 Grand Steet, 5th floor New York, NY 10013 T +1 212 966 2207 F +1 212 966 2214 salesnewyork@actarbirkhauser.com All rights reserved © of the edition, Actar – ­ Barcelona 2012 © of the texts, their authors © of the images, their authors Printed and bound in the European Union ISBN: 978-84-15391-20-3 DL: B-11318-2012 Every effort has been made to contact copyright holders of images published herein. The publisher would appreciate being informed of any omissions in order to make due acknowledgement in future editions of this book. www.davidchipperfield.co.uk www.b720.com www.europigments.es www.bayferrox .com www.colored-concrete-works.com