Top Opt Shell is a monumental free-form concrete sculpture in Mexico City.

Challenging the traditional mode of creative practices where the design precedes the analysis, we developed a design workflow using inverse engineering analysis to mediate the design aesthetics, structural performance, material ecology, and existent construction craft.

The shell uses topological optimization as its generative creative force, the results were then iteratively modelled and analysed to satisfy design aesthetics, structural performance, material consumption and traditional construction craft techniques, these all both converge and get consolidated in an elegant solution.

The shell was a milestone in the continuous efforts of R-Ex to merge the most innovative and efficient design methods pushing both quantitative structural performance and qualitative design with the existent mexican construction trades and their inherent material knowledge. The shell was built in 10 days.

A collaboration with:

Alicia Nahmad (R-Ex)
Shajay Bhooshan (ZHCODE)
Mustafa El Sayed (ZHCODE)
Chikara Inamura (Matsuro Sasaki Engineers)
Asbjorn Sondergaard (ODICO)
Josh Zabel (Kreysler Associates)

Full credits


ZHCODE: Filippo Nassetti, David Reeves, Marko Margeta, Shajay Bhooshan, Patrik Schumacher
BRG: Mariana Popescu, Matthias Rippmann, Tom Van Mele, Philippe Block

KnitCrete technology

BRG: Mariana Popescu, Tom Van Mele, Philippe Block
Chair of Physical Chemistry of Building Materials, ETH Zurich: Lex Reiter, Robert Flatt

Fabrication and construction

BRG: Mariana Popescu, Matthias Rippmann, Alessandro Dell’Endice, Cristian Calvo Barentin, Nora Ravanidou
R-Ex: Alicia Nahmad Vazquez, Horacio Bibiano Vargas, Jose Manuel Diaz Sanchez, Asunción Zúñiga, Agustín Lozano Álvarez, Migue Juárez Antonio, Filiberto Juárez Antonio, Daniel Piña, Daniel Celin, Carlos Axel Pérez Cano, José Luis Naranjo Olivares, Everardo Hernández, Ramiro Tena.

Structural engineering

BRG: Andrew Liew, Tom Van Mele

Concrete development

Holcim Mexico: Jose Alfredo Rodriguez, Carlos Eduardo Juarez, Delia Peregrina Rizo

Site construction coordination

R-Ex: Alicia Nahmad Vazquez


ETH Zurich
NCCR Digital Fabrication
Zaha Hadid Architects
Steiger Participations SA
Holcim Mexico
Imerys Aluminates
Boston Consulting Group

Special thanks

Grupo Altiva
UNAM Arquitectura