Criss-crossing lengths of aluminium cover the glass facade of this Barcelona skyscraper by Spanish architects EMBA.

The 25-storey Diagonal ZeroZero tower is located at the north-east end of a road that spans the entire city, overlooking both the city centre and the sea.

The building has a diamond-shaped plan and a 40 metre-high atrium on the ground floor, which is open to the public.

Upper levels contain a two-storey auditorium, open-plan offices and a boardroom for telecommunications company Telefónica.

Photography is by Aleix Bagué and Eloi Hortoneda of EMBA.

The following details are from the architects:

Torre Telefonica Diagonal ZeroZero

The position of Diagonal ZeroZero Tower is exceptional: it is located at the origin of Diagonal, Barcelona’s main avenue; it is very visible from the city and from the coast; and it lays on the border between the consolidated city and the large expanses of public space in the Forum area. Its immediate surroundings consist of isolated buildings in a diverse context of different scales and uses that generate at the same time a metropolitan center and a local neighborhood still in formation.

It is a contextual tower that has a double reading, from near and afar, in response to the two scales that such tall buildings must address. Taking the urban directions that form the perimeter of the plot as generators of its form, it is a trapezoidal prism, sharp and stylized, a clean and serene form, whitish and light, which reveals dynamic volumes that respond to the different specificities of the interior program and relate to the various heights of nearby buildings. The exterior responds to the city and the view from afar, and the interior responds to the program and the close-up vision.

The corporate program that the tower hosts has a major public part that will connect it to urban flows, situated on the ground floor, which actually comprises three interrelated levels, around an atrium 40 meter high that follows the slope of the adjacent Plaça Fòrum. This direct visual and physical continuity with the city will help the tower benefit from civic activities and will facilitate citizens to participate and enjoy the activities in the building.

Inside the tower four singular points make the ensemble dynamic and generate a variety of interior experiences despite being a relatively conventional program of corporate headquarters: the main lobby atrium, facing Diagonal; an atrium on the 17th level that goes all the way up to the top of the building, facing the Maresme coast; the terrace and the double height the Board Room, located on the 23rd floor; and the auditorium, which occupies two floors and is split into an orchestra and two amphitheaters that can operate autonomously for smaller groups.

The upper floors are open-plan office spaces, taking advantage of the structural system, a tube-in-tube scheme, with a bearing central core and a perimeter structure along the façade.

The perimeter structure is split into two parts: very small and slender vertical interior pillars that only take compression stresses, and external elements that bear horizontal forces and torque. These create a diamond lattice facade that follows the stresses of each part of the building, with the greatest concentration of bearing elements in the lower half and less so in the upper parts. The floors are solid concrete slabs that transmit these horizontal forces to the central core.

The facade is a modular curtain wall made of white aluminum profiles and extratransparent glass with white ceramic paint serigraphy, according to a vertical pattern that reinforces the slenderness of the building.

In combination with the inner structure, placed every 1.35 meters, and the exterior structure, this pattern contributes to the diffusion of solar light and to glare control, generating interiors of great quality of perception.

Location: Barcelona
Developer: Consorci de la Zona Franca de Barcelona
User: Telefónica sa
Years: 2006-2010
Plot area: 4.044 m2
Height: 110 m
Floors: 25 above ground, 3 underground
Above ground built area: 25.300 m2
Underground built area: 8.622 m2

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Team
Architects: EMBA_Estudi Massip-Bosch Arquitectes
Principal Enric Massip-Bosch
Project directors: Aleix Antillach, Elena Guim, Jon Ajánguiz
Architects: Esteve Solà, Ricardo Mauricio, Carlos Cachón, Cornelia Memm, Cristina Feijoo, Heidi Reichenbacher, Rita Pacheco, Rodrigo Vargas, Jana Alonso, Marta Marcet
Prescription + regulations: Montse Galindo, arch.
Document control: Glòria Andrés, arch.
Arch. students: Laura Rodera, Megan Charnley, Miguel Orellana, Jabi Fernández
Quantity surveyors: aumedes dap — Xavier Aumedes, Gemma Rius, Cesc Deharo, Anna Soler
Structures: MC2— Julio Martínez Calzón, Pietro Bartalotta, Luca Ceriani
Facilities: master enginyeria — Marc Jaumà, Luis Martin
Elevator consultancy: japssen — Johannes Maasberg
Safety control: aumedes dap — Marta Serra
Project management: aynova

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Rendering: EMBA, Rupert Maurus
Models: Eloi Hortoneda-EMBA, Andrea Sanglas
Photography: Aleix Bagué, Eloi Hortoneda-EMBA

Contractors
Initial works: dragados
Foundations: terratest
Underground construction: guinovart & osha
Tower and finishes: fcc
Installations: sogesa
Elevators: thyssen