As a matter of fact, the construction process in Barcelona has been utilizing 3-D printing for 14 years, introducing the technology in 2001 as a way of speeding up the prototyping of the building’s many complex components.

The process uses powder-based stereolithographic 3-D printers, which build prototypes layer-by-layer, resulting in a material similar to plaster. This is important to the workshop at the Sagrada Família, because it allows craftsmen to easily alter the prototypes by hand, to meet the demanding specifications of the building.

Peter Sealy, a PhD candidate at the Harvard University Graduate School of Design, whose work includes research on casting and the persistence of indexicality in architectural practice, said: “Antoni Gaudí made few drawings for Sagrada Família, which in any case is so complex as to be rather undrawable, at least with normal architectural projections. What he did leave upon his death in 1926 was a geometric system of ruled surfaces (making the cathedral undoubtedly a “proto-parametric” design) and a working method which translated these geometries into plaster models. Many of Gaudi’s models were smashed by anarchists during the Spanish Civil War, but the surviving fragments can now be digitized using 3-D scanners.

“Gaudi’s design intentions can be reverse-engineered from these computer models, which can then be used for design development (the working tradition of Gaudi’s atelier continues, now with the 3-D printing of plaster models) and fabrication, with stone cut robotically and concrete poured into moulds made from 1:1 scale 3-D prints.”

Consulting architect to the Sagrada Familia since 1989, the New Zealander Mark Burry and his Melbourne- and Barcelona-based team have worked on these processes of digitization in order to unlock Gaudi’s methodologies.