In its initial stages the archive did not have a building of its own. Like all early archives it consisted literally of storage trunks for protecting documents. But through its history is has been housed in various places. In their visits in 1635 and 1636 Molina and Medrano saw the need for the housing of the university's documents in a specific place. As a result the archive was placed in the sacritium of the College of Fonseca.
When on the 21st of September 1769 the university took possession of the "Regulares Expulsos " building, the archive was transferred to its new home with great solemnity. The documents were moved to the new building in a procession in which all the college students were on hand dressed in full regalia.
In latter years the archive was moved to the third floor of the school of History in a space which was not large enough to satisfy its need over an extended period of time.
But eventually the University felt the need to find a specific building that could satisfy the need of the ever expanding archives both in terms of care taking and facilitating research.
With this in mind various studies were done before selecting the archives' current site in the historical Casa Simeón in the historic old town of Santiago on the Rua Casas Reais. The building has been restored and decorated with its use of an archive building in mind. The lot on which the building sits is 465 square meters and the building has an interior space of 2,590 square metres. It is made up of six floors of which are completely dedicated to the storage of documents.
The ground floor consists of a Reception area, Conference and Exhibition room, with a capacity for 50 people and a fully equipped restoration workshop.
The third floor is divided into office spaces, a boardroom and library. There is also a deposit for documentation.
On the top floor are the Consulting Rooms with capacity for 40 people and a workroom for the archive staff.