Architect working on Sagrada Familia: It’s a dream come true

Alejandro Seoane has worked as an architect at the Sagrada Familia in Barcelona, Spain, for 13 years. Today, he plays a key role in the basilica's development. Since joining the technical office in April 2013, he's participated in many major projects. These include constructing the western sacristy and finishing the towers of the Evangelists and the Virgin Mary.

He also helped design the basilica's floor and its liturgical layout. This involved creating the pews, the cross, and the processional candles. Additionally, he designed various wrought-iron decorative elements for both the interior and exterior. Today, he's working on the project for constructing the Sagrada Familia's main facade, the Facade of Glory. In everything he builds, he strives to follow the design principles of the architect, Venerable Antoni Gaudí.

The year 2026 should mark the end of the Sagrada Familia's construction (sort of). As this date approaches, the 45-year-old architect speaks with Aleteia. He reflects on the cathedral's construction progress and explains how his work inspires his life.

Aleteia: For Gaudí, the Sagrada Familia was his life's work. What’s your connection to the basilica? What does working on such a legendary monument mean to you?

Alejandro Seoane: My relationship with the basilica began when I was 13 years old. I visited an exhibition at La Pedrera [a building by Gaudí that is now a museum, Ed.]  that deeply affected me. It moved me so much that I bought a book about the building, by Joan Bassegoda i Nonell.

This book frequently mentioned Gaudí's workshop at the Sagrada Familia. So, I insisted my father take me there the following weekend. The impact of that first visit was enormous.

I remember the Nativity and Passion facades were already finished at the time. The nave was just beginning to rise. The choirs and the first columns were under construction, and an immense space was taking shape.

From that day on, I knew I wanted to work there when I grew up. Even before that, I knew I wanted to study architecture. I wasn't exclusively focused on Gaudí's work, but I already desired to become an architect. Today, working at the Sagrada Familia represents a great challenge and a significant responsibility for me.

Do you manage to reconcile fidelity to Gaudí's style with contemporary innovation?

Alejandro Seoane: Without a doubt, this is the great challenge we all face at the Sagrada Familia. We must remain faithful to Gaudí's style while simultaneously integrating modern innovation.

Today, construction and engineering techniques work in our favor. They allow us to achieve incredible precision and the greatest fidelity possible to the forms and structures Gaudí imagined.

However, there's another increasingly important aspect: the world of infrastructure and facilities. This is the main challenge we face today. It requires spaces that didn't exist in Gaudí's time, and we have to integrate these modern needs without altering his original design.

Ultimately, our biggest challenge is maintaining this fidelity without introducing new elements that distort the basilica's layout.

Are there any construction elements or details that have particularly inspired you?

Alejandro Seoane: It's hard to choose just one element that inspired me the most. Since I started working at the Sagrada Familia in 2013, every project in which I have participated has taught me something new.

The first major project I joined was the interior design of the Passion Facade sacristy. I was entrusted with overseeing the design of the entire interior enclosure, including the furniture and the main level's layout.

For this task, I drew inspiration from the geometric modulation Gaudí used in his liturgical furniture and woodwork. His designs were primarily based on the equilateral triangle.

He used this basic shape for many pieces, such as the ambo, the crypt's confessionals, and the doors of the Roser cloister. Starting from this foundation, I studied in great detail how he worked with wood, joints, and iron. This guided me.

Later, when I was tasked with designing the pews for the faithful, I used a pew from the Colònia Güell crypt as my reference. This was a piece designed by Gaudí himself.

In reality, it's impossible to focus on just one element. The Sagrada Familia is so vast and complex that each new project inspires us differently. We're always looking for a strong reference point, whether inside the basilica or in Gaudí's other works, in order to maintain coherence and continuity in our designs.

What are the main technical or artistic challenges left to overcome before the final completion?

Alejandro Seoane: Right now, one of our main technical challenges is the cross crowning the central tower, which is dedicated to Jesus Christ.

The cross is an absolutely unique element. This is true not only because of its symbolic dimension as a large four-armed cross crowning the church, but also due to its structural complexity.

We used ultra-resistant concrete with minimal thicknesses of about four inches. Standard regulations would normally require almost eight inches. This reduction represents a major technical and engineering challenge.

The cross is a prefabricated piece made up of six parts: the trunk, the base, the shaft, the crowning arm, and four observation decks. We had to design and assemble each component with extreme precision.

Looking ahead, another challenge will be constructing the new Facade of Glory. It will be comparable to the Nativity and Passion facades.

Here, the technical difficulty lies less in the design and more in the construction methodology. We need to translate a traditional stone-and-mortar system into modern techniques. This means using large prefabricated elements while preserving the original essence and spirit of Gaudí's bell towers.

As for the sculptural challenge, the Facade of Glory is a massive undertaking. Three sculptors are currently working on it. The ensemble will have the dimensions of a great altarpiece, measuring roughly 148 feet wide and over 197 feet tall.

Beyond its sheer scale, its complexity lies in its symbolic content. It depicts the Last Judgment, the works of mercy, and various trades. It's a representation of the afterlife. This is a historically difficult theme to tackle, and it's even harder to address in the 21st century, where this type of iconography is rare.

Are there any elements or details you're particularly hoping to highlight in the project's final phase?

Alejandro Seoane: In the project's final phase, I'm most looking forward to the main facade's grand portico and, above all, the grand staircase that will cover Carrer de Mallorca [a street that passes in front of the basilica, Ed.].

This complex will include two large monuments representing water and purifying fire, situated in front of the Baptistery and Blessed Sacrament chapels. This is a highly innovative feature, both technically and symbolically.

Building over a street involves many structural constraints, but it's also an operation with immense formal impact. We aren't just building a simple staircase with two sculptures. According to Gaudí's original design, each monument will reach roughly 65 feet in height. That's almost the size of a residential building in Barcelona's Eixample district.

Gaudí had already anticipated this solution. He raised the church’s entire floor level about 16 feet above Carrer de Mallorca. This street was—and still is—an essential traffic route that couldn't be interrupted.

For this reason, we designed the staircase like a bridge. It will be a raised platform allowing vehicles to pass underneath while pedestrians cross above without any change in elevation.

As a result, the pavement in front of the basilica’s exit will extend to the opposite city block, where this grand staircase will take shape. It will essentially feel like an elevated plaza. This space will visually and symbolically connect the basilica to the city, presided over by the two monuments of fire and water that will mark the main entrance.

What emotions or reflections does the prospect of finally seeing the project finished inspire in you, after over a century of work?

Alejandro Seoane: I perfectly remember my first visit to the Sagrada Familia when I was 13. From that moment on, I came every Friday after school to see how the construction was progressing.

Back then, my dream was simply to see the inside of the finished church one day. I never could have imagined I'd live to see the entire building completed. Because of this, the personal emotion I feel is immense.

I remember a newspaper article from around 1994 or 1995. It stated—very optimistically—that the basilica might be finished by the year 2100. Being able to think today that we'll actually see it completed is an incredibly profound and special feeling. It connects directly back to that fascinated child who used to watch the church grow.

Furthermore, if you look closely, the progress we've made in recent years has been spectacular. The Nativity Facade took nearly 40 years to complete, including the years Gaudí worked on it and the period following his death. Despite initial financial difficulties, builders completed the Passion Facade in about 25 years. In contrast, we've raised the central towers in just one or two decades, and now we're preparing to finish the main facade.

This is an accomplishment that seemed impossible 30 years ago. Even the Construction Board at the time couldn't have imagined we'd come this far, this quickly. Seeing it now, so close to completion, is a feeling that's hard to express in words.