OBJECTIVE

The world financial crisis gave us the right time and oportunity to think and develop a different office building, not generic. Costanera Lyon 2 was forced to use cantilever slabs in order to maximize all the FAR. The proposed cantilever slabs didn’t worked under gravitational and seismic forces. The solution was to add a series of perimetral walls in order to provide torsional rigidity to the structure. In order to allow more views from inside the walls became a series of Vierendeel beams that carry the dead load weight of the building trough the façade and release the interior of the columns form the interior columns. The building was rethought and designed as an essay of prefabricated elements: 21 Vierendeel beams, 16 slabs, 1 core and 14 scissor base columns. Because of Chile seismic condition it was highly recommended to build Costanera Lyon 2 as one piece. The façade became a paradox of two opposite ideas, one reinforced concrete form that really works as a house of cards; if one element is removed the whole building will collapse.

CONTEXT

The project is located in the corner of Andres Bello Avenue and Santa Magdalena street, in a neighborhood named as "Barrio Suecia" in Providencia, the site has very strong urban and natural condition located right in front of the Mapocho River and the longitudinal park next to it. Costanera Lyon 2 finally completed and old "cul de sac" pedestrian passage known as Plaza del Sol, which was part of pedestrian walkway masterplan designed for Providencia in 1978 by German Bannem, an important Chilean Urban Designer. Since 2000 until 2010 all the neighborhood known as "Barrio Suecia" turned into dangerous nightlife area. In 2010 the City council decided to quit the nightlife licences and propose a mix use area with a mid rise height regulation for this area. Costanera Lyon 2 is the second stage of a project that started in 2010, after the world financial crisis becoming the first step in the urban renewal of the old"Barrio Suecia". The project proposed a 16th stories height office building and the final design for the interior walkway through a private owned public space that today has become a a very succesfull gastronomic spot. This walkway has become the only walkway conection from the core of city block to the river , the park and bikeway parallel to Andres Bello Avenue. If you walk trough the walkway until the park is possible to see the Andes and most of the valley condition where Santiago is located, conecting two diferents scales in one block.

PERFORMANCE

Pedestrian level: The project has bring life to the all the city block from the core: The first floor is full of restaurants, the interior pedestrian pathway was extended into the building by 3 exposed stairs step that develops under the cantilevers. These stairs are absolutely open to the public space, extending pedestrian flows within the second floor and the -1, where a big travel agency is located with direct access to the street. Inside the tower: All the columns were releases from the interior of the offices in order to allow more flexibility for the users and optimize the structure as thermal mass on the facade. The facade is 45% transparent vith low -U values allowing for very confortable office spaces where most of the office workers can open a window if they feel like to in the middle season days. Parking space: The 5 underground parking levels have a series of cuts in the slab and a large vertical courtyard with a reflecting pool in the last level that creates an unexpected hall for the office workers and allows natural light and ventilation on the parking. The building doesn´t require underground ventilation. Penthouse: There is a swimingpool in the 16th floor to improve the quality of life of their office workers.