Exploring isovist fields: A comparative study of churches in reconstruction plans for postearthquake Lisbon

Abstract

Following the Lisbon 1755 earthquake, Manuel da Maia (1677- 1768), chief engineer of King D. José I (1714-1777), commissioned six plans for the city's reconstruction. We analyze these plans weighing how they addressed the challenges of building a modern city of the XVIII century. In them, churches had different roles in the urban morphology of the city. We investigate their interplay over the plans. The analysis of the importance of religious buildings in the city plan was made through the visual impact that those buildings had in the public space. Using isovists, we examine the visual impact of religious buildings on public space. Our results indicate that all plans, except the chosen one, promoted a greater visual impact of churches in public space. Plan 6 proposed a patriarchal church in Terreiro do Paço, with an extreme impact on the city's visual landscape. Conversely the chosen plan presented a similar visual impact of churches in the plan as the pre-1755 city. This resulted from the removal of churches from the main streets and their integration inside the city blocks. This plan presented a similar level of visual impact, comparable to the pre-1755, but with a completely different approach to the street drawing. Overall, this study sheds light on how different reconstruction options for the city of Lisbon could have impacted the city being rebuilt. The aftermath of the 1755 earthquake provided an opportunity not only to rebuild the city, but also to redefine the power balance within the kingdom and to shift the importance of the church as a central aspect of city life.