Mauricio Cortés Sierra has spent nearly two decades inside one of the most consequential construction projects of the past century. As lead architect of Barcelona’s Basilica de la Sagrada Família, he oversaw the completion of the cathedral’s six central towers and directed installation of the defining element: a 12-ton luminous cross, composed of steel, enameled ceramics, white onyx, and glass, placed atop the Tower of Jesus Christ at 172.5 meters on February 20, 2026. Pope Leo XIV inaugurated the tower in June, on the centenary of Gaudí’s death. On October 14, Cortés comes to EMPAC in Troy to explain how his team pulled it off.
About the Lecture
The talk — “Sagrada Família: The Dream of a Genius, A Collective Endeavour Across Generations” — is the Steven Ehrlich ’69 Architecture Lecture, part of RPI’s School of Architecture Fall 2026 series, and begins at 5:00 p.m. in the EMPAC Theater.
The challenge Cortés will address is the one that has shadowed the project for generations: Gaudí “did not leave all the final plans.” His team has had to interpret the architect’s scale models and experimental geometries, translating them through parametric modeling, high-precision manufacturing, and materials Gaudí never had access to. The cross alone required precise calibration — it needed to be “light enough so it can sit on top of the tower, but not too light so that it will sway.” Ultra-high-performance concrete at just 5cm thickness was part of the answer; the cross arms were manufactured in Germany before assembly.
The central towers were completed over five years, from 2021 to 2026. Cortés has also spoken about his effort to secure the Lord’s Prayer in Nahuatl on the bronze doors of the Glory façade (the cathedral’s still-incomplete final phase), working with his mother and scholar Miguel León-Portilla on a contemporary version of the text.
Cortés joined the Sagrada Família’s Construction Board in 2006, first learning Gaudí’s methods by replicating neogothic stonework piece by piece. A native of Mexico City’s Roma neighborhood and a UNAM graduate, he arrived in Barcelona in 2002 to complete his doctorate at ETSAB, the same institution where Gaudí trained.
Venue & Logistics
The lecture takes place in the EMPAC Theater at Rensselaer Polytechnic Institute in Troy, one of the more serious experimental arts spaces in the Capital Region and a room suited to programs of this scale. The event begins at 5:00 p.m.; RPI notes that design studios end early to allow timely arrival.
Tickets
No ticket price was available from sources at the time of publication. Tickets are available through EMPAC’s ticketing system or by calling 518.276.3921. Buy tickets