The "Instituto de Ciencias de la Construcción" building is one of the most singular engineering design done by Eduardo Torroja: it was started in 1951. This study focused on the Institute façade-building materials has been carried out in the 100th anniversary of his birth. The analysis has revealed that the design of the original project has been of a great importance for the good conservation of the external walls. The pointing mortar characterization of its brick walls by instrumental techniques (infrared spectroscopy. X-ray diffraction, scanning electron microscopy with EDS) reveals that calcite is its main component, with gypsum presence in polluted external zones and silica compounds from the sand. The obtained results indicate a good compatibility between mortars and façade bricks.