In the Chapel del Retiro, the typically stereotomic mass of the building is vaulted into the air on foundation blocks. Mass is dematerialized and disconnected. The floating concrete walls create an unsettled perception of how the structure is supported. Undurraga exaggerated the effect by extending the concrete walls beyond their supports, creating a cantilever condition that hovers above the ground.
The effect of floating is also pronounced on the interior of the building where no structural support is visible. Attached to the inside face of the concrete frame, a steel frame supports the installation of the wood cladding – a composition of recycled railroad ties. This cladding constricts the view out and conceals the concrete construction. A similar condition occurs at the roof. A narrow skylight runs around the entire perimeter of the chapel’s ceiling. The roof’s structure – a series of lightweight trusses – is concealed above, giving the effect of a floating ceiling in the space. The progressive dematerialization of these heavy elements is the primary tectonic – or atectonic in this case – expression of the chapel.
This is an excerpt from Chapter 15 of Introducing Architectural Tectonics.
Drawing | © Chad Schwartz | Floating wall section.