The current building, known as House of 11 Windows, has its origins in the residence of Domingos Bacelar, built in the mid-18th century. A city map drawn by Schwebel in 1754 shows the two-story house with six windows and a mansard. Undated drawings by the same author show the house with eight openings.

Ever since 1716, the need for a military hospital was discussed in the city. On the following years, two precarious constructions were used to treat the ill, Forte do Castelo and Convent of Boaventura.

In 1768, Bacelar's house was bought by governor Ataíde Teive to serve as Royal Hospital. From Teiveâ??s letter to Captain General Mendonça Furtado on the purchase of the house, we can infer that it was still under construction, "and not yet finished"?. The adaptation to its new function was handed to Antônio Landi; the sketches for this project are still preserved. The main façade of this twostory building features eleven symmetrically distributed openings, windows and doorwindows, with straight lintels and preceded by railings, in addition to the main door. Its solid volume is divided by a simple entablature and features pillars on the quoins, in a robust and unpretentious solution, in the taste of that times Portuguese architecture. 

The façade facing the river is more elaborate and reflects the intervention of Italian architect Antônio Landi (1713-1791), with its opening in arches forming balconyshaped loggias in the central body, open on the ground floor and covered with railings on the top floor.

When the building was transferred to the military it suffered a few major interventions. In terms of the Landian façades, the most relevant were the addition of a triangular pediment, sided by obelisks, to the main façade, and the defacement caused by the closing of the openings facing the river. These modifications were undone in a series of restorations and reforms undertaken in the 2000s. Isabel Mendonça points out that it is hard to define the extent of Landi's interventions on the house built by Domingos Bacelar - whether existing of unfinished -, but she attributes the loggias to the architect, who had already used this resource in other projects . Since all previous references and sketches portray a rectangular building, we can also attribute to Landi the lateral body, conforming the present-day L-shaped floor plan. This body was modified during the last reform, losing the openings that faced the river.