Maag-Tower (now: Prime Tower)

Location Zurich, Switzerland

Programme High-rise office building, 36 floors, 126 m hight, entrance hall, bank branch, varying office types, gastronomy, restaurant and conference area on the top floors

Competition 2004, 1st Prize

Planning/Construction 2004–2011

Client Swiss Prime Site AG, Olten
Client’s Representative: Perolini Baumanagement AG, Zurich

Team G/G Stefan Thommen

Total Contractor ARGE Prime Tower
Losinger Construction AG und Karl Steiner, Zurich

Landscape Architecture Schweingruber Zulauf Landschaftsarchitekten, Zurich

Cost Planning/Scheduling Bauprojekt /TU-Submission: b+p baurealisation ag, Zurich

Structural Engineer Dr. Schwartz Consulting AG, Zug

Ventilation Engineer Waldhauser AG, Münchenstein

Facade gkp fassadentechnik ag, Aadorf

Furnishings Gigon / Guyer Architekten with Studio Hannes Wettstein, Zurich

Art within Architecture Adrian Schiess, Zurich und Mouans-Sartoux, France
Harald F. Müller, Öhningen, Germany

«Platform» Office Building

In the immediate vicinity of Hardbrücke railway station, the seven-story office building called Platform completes the ensemble comprising the high-rise Prime Tower and its annexes Cubus and Diagonal. The building’s volume, with various angles, reacts to the urban situation, providing a coherent link between the station and the new central square. A two-story-high passage through the building connects the square with the public pedestrian and bicycle path along the side of the tracks as well as with the new pedestrian underpass to Hardbrücke Station. In addition, the passage acts as a generous covered area outside the entrance foyer.

With its pronounced horizontal and layered design, the building contrasts with the Prime Tower nearby, effectively forming its reclining counterpart. As in the tower, the stories increase their floor area as the building rises, made possible by various projections. the volume of the building is also subdivided by courtyards that cut into the west and south sides and ensure well-lit office spaces within, as well as by the angular projections in the façade.

The central, prestigious entrance foyer forms an additional internal open area. A tall atrium flooded with natural light links the entrance level with the office floors above. Its function as a hub that lends the building its identity is additionally underlined by the open staircases and adjoining seating areas on the office floors. Dark glass balustrades mirror the space and the light in multifaceted reflections, creating a kaleidoscope effect.

Next to the entrance foyer on the ground floor are a restaurant, a cafeteria, and an auditorium. A wide, inviting staircase leads from the entrance level to the customer lobby on the first floor, from which the various conference rooms can be accessed. the levels above provide office space for around 1,000 staff. Although the building has been conceived as a corporate headquarters, the positioning of core facility areas permits a variety of office typologies if required in the future, including the division of each floor into a maximum of four separate rental units. Wall and ceiling paintings by Nic Hess, wallpaper and drapes by Lachmayer/Nobis and a textile sculpture by Ernesto Neto complete the interior.

To be able to meet changing spatial needs or different uses without radical structural alterations, the building has been designed as a load-bearing skeleton structure with reinforced cores.

The glazed façade is articulated by horizontally layered bands of parapets and windows. The double windows hold sunblinds in between and help reduce noise from outside. The inner windows can be opened for ventilation purposes toward the interim space of the double-skin façade. The slightly reflective outer glazing shell and parapets accentuate the building’s folded structure.

Location Zurich, Switzerland

Programme Seven storeys office building, 1'000 workplaces, atrium as central entrance hall, restaurants, shops, auditorium

Commission 2007

Planning/Construction 2007–2011

Client Swiss Prime Site AG, Olten

Gross Floor Area 28‘853 m2

Team G/G Christian Maggioni (Team Manager), Franziska Bächer (Project Manager from 11/ 2007), Stefan Thommen (Project Manager until 06/ 2007), Christoph Rothenhöfer (Project Manager until 05/ 2007), Markus von Dellingshausen, Philippe Volpe, Karla Pilz, Armin Baumann, Pieter Rabijns

Total Contractor HRS Real Estate AG, Zurich

Landscape Architecture Schweingruber Zulauf Landschaftsarchitekten, Zurich

Structural Engineer Planning: ARGE Dr. Schwartz Consulting AG, Zug and Dr. Lüchinger + Meyer Bauingenieure AG, Zurich and Freihofer & Partner AG, Zurich
Construction: Ribi + Blum AG, Romanshorn

Electrical Engineer Planning: IBG B. Graf Engineering AG, St.Gallen
Construction: Herzog Kull Group Zürich, Schlieren

Building Physics Engineer BAKUS GmbH, Zurich

Heating/Cooling Planning: PB Peter Berchtold, Ingenieurbüro für Energie und Haustechnik, Sarnen
Construction: Lippuner Energie- und Metallbautechnik AG, Grabs

Ventilation Engineer Waldhauser AG, Münchenstein

Lighting Consultant Planning: Ernst Basler + Partner, Zurich
Construction: Regent, Zurich

Plumbing Planning: PB Peter Berchtold, Ingenieurbüro für Energie und Haustechnik, Sarnen
Construction: Huustechnik Rechberger AG, Zurich

Facade Planning: gkp fassadentechnik ag, Aadorf
Construction: Fahrni Fassadensysteme AG, Lyss

Furnishings Gigon / Guyer Architekten, Zurich
workspaces intern: Off Consult, Zurich

Art within Architecture Nic Hess, Zurich
Herbert Lachmayer and Margit Nobis, Vienna, Austria
Ernesto Neto, Brazil

Photos © René Dürr
© Walter Mair
© Shinkenchiku-sha, Tokyo
© Thies Wachter
© USM Möbelbausysteme / Dani Suter

Refurbishment of Former Diagonal Industrial Building, Maag-Areal

The Diagonal building, the former Maag cogwheel factory, has been preserved as a fascinating architectural testament to the site’s industrial past. The load-bearing structure and the façades have been carefully revitalized. the surviving slender glazing bars were restored and are complemented by insulating glazing on the interior. The Diagonal building contains a restaurant on the ground floor and gallery spaces on the upper floors.

Location Zurich, Switzerland

Programme Listed industrial building, with restaurant in the ground floor, art galleries, offices

Competition 2004, 1st Prize

Client Swiss Prime Site AG, Olten
Client’s Representative: Perolini Baumanagement AG, Zurich

Gross Floor Area 2‘759 m2

Team G/G Planning/Construction: Stefan Thommen (Team- and Project Manager) Pieter Rabijns (Project Manager), Alex Zeller, Urs Meyer, Raffaella Bisceglia
Competition: Stefan Thommen

Total Contractor ARGE Prime Tower
Losinger Construction AG and Karl Steiner, Zurich

Landscape Architecture Schweingruber Zulauf Landschaftsarchitekten, Zurich

Cost Planning/Scheduling Building Project/General Contractor Submission: b+p baurealisation ag, Zurich

Structural Engineer Competition (C): Dr. Schwartz Consulting AG, Zug
Submission (S): Dr. Schwartz Consulting AG, Zug and Dr. Lüchinger + Meyer AG, Zurich and Freihofer & Partner AG, Zurich
Execution (E): Walt + Galmarini AG, Zurich with Dr. Schwartz Consulting AG, Zug, Dr. Lüchinger + Meyer AG, Zurich, Bänzinger Partner AG, Richterswil, Freihofer & Partner AG, Zurich

Electrical Engineer S: IBG Graf AG, St.Gallen
E: Hefti Hess Martingnoni, Zurich

Fire Safety S: Makiol + Wiederkehr, Beinwil am See
E: Gruner AG, Basel with Makiol + Wiederkehr, Beinwil am See

Heating/Cooling S/E: PB P. Berchtold, Sarnen

Ventilation Engineer C/S: Waldhauser AG, Münchenstein
A: Hans Abicht AG, Zurich

Plumbing S: PB P. Berchtold, Sarnen
E: GRP Ingenieure, Rotkreuz

Sprinkler Consultant S: PB P. Berchtold, Sarnen
E: GRP Ingenieure, Rotkreuz

Photos © Valentin Jeck
© Walter Mair
© Thies Wachter

Awards Auszeichnung für gute Bauten der Stadt Zürich 2011–2015

Cubus Office Building, Maag-Areal

The Cubus annex building, a seven-story structure with a pentagonal ground plan, houses offices on the upper floors and at ground level retail outlets, access to the parking garage, and deliveries for the entire complex. Of note here is that, due to the excellent public transport connections to this site, relatively few parking spaces are required. The load-bearing structure is executed in white-pigmented exposed concrete. Externally fixed glazing panels give the façade its character and help to reduce noise from the elevated road nearby.

Location Zürich, Switzerland

Programme Office building with 7 floors, ground floor with delivery and parking access for the Prime Tower and its annex buildings, retail, offices, upper floors concerning the load capacity are constructed for archive use

Competition 2004, 1st Prize

Client Swiss Prime Site AG, Olten
Client’s Representative: Perolini Baumanagement AG, Zurich

Gross Floor Area 6‘206 m2

Team G/G Stefan Thommen (Team and Project Manager), Pieter Rabijns (Project Manager), Alex Zeller, Urs Meyer, Raffaella Bisceglia
Competition: Stefan Thommen

Total Contractor ARGE Prime Tower
Losinger Construction AG and Karl Steiner, Zurich

Landscape Architecture Schweingruber Zulauf Landschaftsarchitekten, Zurich

Cost Planning/Scheduling Building Project/General Contractor Submission: b+p baurealisation ag, Zurich

Structural Engineer Competition (C): Dr. Schwartz Consulting AG, Zug
Submission (S): Dr. Schwartz Consulting AG, Zug and Dr. Lüchinger + Meyer AG, Zurich and Freihofer & Partner AG, Zurich
Execution (E): Walt + Galmarini AG, Zurich with Dr. Schwartz Consulting AG, Zug, Dr. Lüchinger + Meyer AG, Zurich, Bänzinger Partner AG, Richterswil, Freihofer & Partner AG, Zurich

Electrical Engineer S: IBG Graf AG, St.Gallen
E: Hefti Hess Martingnoni, Zurich

Heating/Cooling S/E: PB P. Berchtold, Sarnen

Ventilation Engineer C/S: Waldhauser AG, Münchenstein
E: Hans Abicht AG, Zurich

Plumbing S: PB P. Berchtold, Sarnen
E: GRP Ingenieure, Rotkreuz

Sprinkler Consultant S: PB P. Berchtold, Sarnen
E: GRP Ingenieure, Rotkreuz

Facade C/S: gkp fassadentechnik ag, Aadorf
E: Reba Fassadentechnik AG, Chur

Photos © Walter Mair
© Thies Wachter

Prime Tower Office High-rise
with Annex Buildings Cubus and Diagonal, Maag-Areal

The location of the Prime Tower and its two annexes, the Cubus and Diagonal buildings, is part of a formerly almost inaccessible industrial site that is gradually being converted into a business and residential district with associated services. Situated in the immediate vicinity of Hardbrücke railway station and 126 meters in height, the high-rise is the tallest in Switzerland for the time being. It is not only a distinctive feature of the neighborhood, but also a landmark for the up-andcoming district of Zurich West.

The concept underpinning the Prime Tower is of a building that might be said to assume many guises, although its fundamental structure and the means deployed are relatively straightforward. The design aimed to find a floor plan arrangement that would maximize the number of well-lit workplaces, while also seeking to create a striking architectural form evoking differing impressions depending on the position from which it is viewed. The outcome of these efforts is a building on an irregular octagonal ground plan that confounds conventional expectations by broadening toward the top.

In terms of urban planning, the building’s significance is twofold in relation to its impact when seen from nearby or from a distance. From afar, it appears as an abstract, elegant volume formed from greenish glass that changes depending on whether it is seen from the side (from the north or south) or head-on (from the east or west). The planes of the façade, oriented in various directions, reflect the light and the surroundings in different ways, articulating and subdividing the volume into what might be called gigantic “pixel surfaces”. The impression the building makes when seen close-up also changes with the spectator’s standpoint. These close-up views reveal that the projecting portions of the tower exert an integrating effect on the surrounding buildings.

At Geroldstrasse, an inviting outdoor area between the high-rise and the new neighboring Cubus office building leads to the entrance of the Prime Tower and toward the planned Lichtstrasse. In the southwest, a plaza is created in conjunction with the existing listed Diagonal building and the new Platform office building beside the railway.

The ground floor of the Prime Tower houses retail spaces and a coffee bar for use by both office employees and passers-by. Special features on the top floor include a public restaurant, bistro with a bar, and a lounge, while a private conference area is available on the floor below.

The cores and emergency stairs are arranged so that up to four tenants can occupy offices on the same floor or, conversely, one business can occupy several floors with internal atriums and staircases. The projecting portions of the building create additional office space on the higher and therefore more soughtafter floors, as well as providing greater variety when using the space for different types of offices.

The load-bearing skeleton structure of the tower is made of concrete with reinforcing cores. The variously sized cantilevered projections are supported by slanting the supporting columns over two or three stories. The façade is constructed from insulated triple glazing with a greenish tint. To enhance workspace conditions, and to meet fire regulations, which require smoke ventilation, alternating windows can be opened parallel to the building. The prefabricated windows are frameless on the exterior. They grant the polygonal building the multifaceted appearance of a greenish crystal.

Location Zurich, Switzerland

Programme High-rise office building, 36 floors, 126 m hight, entrance hall, bank branch, varying office types, gastronomy, restaurant and conference area on the top floors

Competition 2004, 1st Prize

Planning/Construction 2004–2011

Client Swiss Prime Site AG, Olten
Client’s Representative: Perolini Baumanagement AG, Zurich

Gross Floor Area Total Prime Tower with Annex buildings: 73‘830 m2
Prime Tower: 53‘461 m2

Team G/G Planning/Construction: Stefan Thommen (Team Manager), Christian Maggioni (Deputy Team Manager), Christoph Rothenhöfer (Project Manager until 2007), Pieter Rabijns (Project Manager from 2007), Alex Zeller, Urs Meyer, Franziska Bächer, Raffaella Bisceglia, Armin Baumann, Karin Winklmann, Roberto Outumuro, Rafael Schmid, Martin Bischofberger, Leander Morf
Competition: Stefan Thommen

Total Contractor ARGE Prime Tower
Losinger Construction AG and Karl Steiner, Zurich

Landscape Architecture Schweingruber Zulauf Landschaftsarchitekten, Zurich

Cost Planning/Scheduling Building Project/General Contractor Submission: b+p baurealisation ag, Zurich

Structural Engineer Competition (C): Dr. Schwartz Consulting AG, Zug
Submission (S): Dr. Schwartz Consulting AG, Zug and Dr. Lüchinger + Meyer AG, Zurich and Freihofer & Partner AG, Zurich
Execution (E): Walt + Galmarini AG, Zurich with Dr. Schwartz Consulting AG, Zug, Dr. Lüchinger + Meyer AG, Zurich, Bänzinger Partner AG, Richterswil, Freihofer & Partner AG, Zurich

Electrical Engineer S: IBG Graf AG, St.Gallen
A: Hefti Hess Martingnoni, Zürich

Heating/Cooling S/E: PB P. Berchtold, Sarnen

Ventilation Engineer C/S: Waldhauser AG, Münchenstein
E: Hans Abicht AG, Zurich

Plumbing S: PB P. Berchtold, Sarnen
E: GRP Ingenieure, Rotkreuz

Sprinkler Consultant S: PB P. Berchtold, Sarnen
E: GRP Ingenieure, Rotkreuz

Facade C/S: gkp fassadentechnik ag, Aadorf
E: Reba Fassadentechnik AG, Chur

Furnishings Gigon / Guyer Architects with C/S: Studio Hannes Wettstein, Zurich

Signage Integral Ruedi Baur Zürich GmbH

Art within Architecture Adrian Schiess, Zurich and Mouans-Sartoux, France
Harald F. Müller, Öhningen, Germany

Photos © Walter Mair
© Thies Wachter
Maagplatz: © Roman Keller

Awards Auszeichnung für gute Bauten der Stadt Zürich 2011–2015