SciELO - Scientific Electronic Library Online

 número102La arquitectura como monedaEspeculación residencial. Experimentos arquitectónicos y negocio inmobiliario en la conformación del suburbio estadounidense de posguerra índice de autoresíndice de materiabúsqueda de artículos
Home Pagelista alfabética de revistas  

Servicios Personalizados




Links relacionados

  • En proceso de indezaciónCitado por Google
  • No hay articulos similaresSimilares en SciELO
  • En proceso de indezaciónSimilares en Google


ARQ (Santiago)

versión On-line ISSN 0717-6996

ARQ (Santiago)  no.102 Santiago ago. 2019 

Works & projects

Building over Plaza de Armas Subway Station: a New Urban Hall

Alejandro Beals1 

Loreto Lyon2 

1 Profesor, Escuela de Arquitectura , Pontificia Universidad Católica de Chile.

2 Profesora, Escuela de Arquitectura, Pontificia Universidad Católica de Chile.


One of the most obvious and widespread forms of financial speculation is the multiplication of urban land: building as much as possible in order to maximize profitability. Hence, when that does not happen, it is remarkable. Especially in this case, where the subway company Metro de Santiago not only decided to build just enough to complete the city without saturating it, but also opted for architectural speculation as a way of giving something back to public space.

Keywords: speculation; building; heritage; mobility; project

Source: Cristian Valenzuela

Figure 1 

With this project Metro adopts a new urban strategy intended at the construction of buildings on top of its underground stations, to protect the continuity of the urban fabric, mitigate the negative impacts on its stations’ surroundings, and take advantage of alternative profits on sites located in areas of high density and demand.

Source: © Beals Lyon Arquitectos

Figure 2 

This particular building is located on the corner of the Catedral and Bandera streets intersection, an area with a strong heritage and pedestrian character in the center of Santiago. Therefore, the project aims to return the building to its original form as part of a continuous façade while configuring the public space around it.

Figure 3 Formwork 

Source: © Beals Lyon Arquitectos

Figure 4 

At the pedestrian level, the most characteristic feature is the station’s entrance hall: a plinth built by a series of reinforced concrete vaults that account for the plot’s restriction to distribute the structural loads along its perimeter. This structural/spatial form becomes the most characteristic feature of the station hall.

Figure 5 Plans 

Figure 6 Plans 

The new urban hall seeks to bring to the city surface something of the atmosphere below and vice versa. On the one hand, a sort of artificial cavern serves as a threshold to the underground world. On the other, for those who disembark here, this will be the first place to approach the most representative icons in the historic center: the Plaza de Armas, the Metropolitan Cathedral, the National Congress and its surrounding gardens, all of which are directly visible from the interior hall.

Figure 7 Cross section 

Figure 8 Longitudinal section 

Two types of vaults of different width alternate in the construction of the structure that contains the void. In turn, each vault is formed by the combination of smaller double-curved formwork modules. These are built by superimposing two plies of plywood cut with a cnc machine and coated with two layers of phenolic plate.

Above the plinth, a substructure of prefabricated concrete columns and a double envelope made of glass and alabaster stone cladding provides an opaque and monolithic appearance from the exterior, while allowing natural light to enter the open plan around its perimeter. Thus, the overall impression is that of a continuous and uniform façade with neighboring buildings, due to the maintenance of materials, lines, and proportions, as well as what we call the ‘fine grain,’ a repetition and decomposition of smaller elements, which can be appreciated by an attentive gaze focused on details.

Fuente: © Cristian Valenzuela

Figure 10 

Figure 11 

At nightfall, the alabaster facades light up from the inside. The formerly opaque volume is transformed into a kind of urban lamp that announces - through a dim, diffuse brightness - the building’s public status.

Source: © Cristian Valenzuela

Figure 12 

Building over Plaza de Armas subway station

Architects: Alejandro Beals, Loreto Lyon

Contributors: Raúl Avilla, Nicolás Frenkiel, Gonzalo Torres, Andrés Lira

Location: Calle Catedral 1111, Santiago, Chile

Client: METRO SA

Structural engineering: Worley Parsons Ingeniería

Construction: PERI Chile

Lighting: Pascal Chataurd (llD)

Materials: Hormigón armado, piedra basalto, alabastro

Built area: 3.850 m2

Site area: 1.100 m2

Project year: 2014-2016

Construction year: 2018-2019

Models: Alejandro Lüer

Renders: RenderLab


Alejandro Beals Architect, Pontificia Universidad Católica de Chile, 2001. MPhil in Architecture from the Royal College of Art (RCA), London (2013), where he researched about blurriness and ambiguity in architecture, under the supervision of professor Nigel Coates. In 2012 he founds Beals Lyon Arquitectos together with Loreto Lyon. He currently teaches studio at the Pontificia Universidad Católica de Chile.


Loreto Lyon Architect, Pontificia Universidad Católica de Chile, 2005. MSc in Environmental Design and Engineering from the Bartlett, University College London (UCL), 2011. In 2012 she founds Beals Lyon Arquitectos together with Alejandro Beals. She currently teaches studio both at the Pontificia Universidad Católica and the Universidad San Sebastián in Chile.

Creative Commons License Este es un artículo publicado en acceso abierto bajo una licencia Creative Commons