Hidden History: Lisbon Rebuilt With a Wooden Skeleton

Reconstruction as a choice

After the earthquake, Lisbon faced a decision that was also political: restore the old street pattern, or build a different city? The plan associated with Sebastião José de Carvalho e Melo, later the Marquis of Pombal, chose an orderly reconstruction of the Baixa district. Streets were widened and laid out in a regular grid. Building fronts and internal plans could be repeated, making a large rebuilding effort easier to organise.

UNESCO’s Tentative List description presents the Baixa Pombalina as an early example of comprehensive post-disaster urban planning. This is a nomination dossier, not a final UNESCO inscription or a universal ranking, so claims such as “the first modern city” need attribution. What is clear is that the rebuilding joined street planning, building regulation and construction methods in a way that attracted later attention.

A structure behind the walls

The gaiola was a timber frame assembled within the building’s masonry. Its diagonal bracing created a three-dimensional skeleton. Wood can flex under movement; masonry provides mass and stiffness. Together, the materials were intended to respond more effectively to seismic forces than an unreinforced wall alone.

The system was not simply a single invention suddenly discovered after disaster. Timber framing and bracing had precedents. The notable step was the standardised use of the frame across a planned district, alongside rules for building dimensions and repeated layouts. A University of Lisbon engineering account describes the cage as an anti-seismic construction system developed during the reconstruction.