Palazzo Guillot stands towards the end of Carrer Major towards Plaça del Pou Vell. It constitutes an extremely interesting model of late Gothic-Catalan architecture, as it renounces linearity and has a more fervent decorative liveliness, thanks above all to the diversification of the openwork weavings.
These figurative motifs, which refer to the airy filigree works typical of the local goldsmithery, echo those shown in the façade of Palazzo Tibau. In Palazzo Guillot, the openings are framed by overlapping squared ashlars and honeycomb columns that follow the shape of the window.
On the ground floor there is a dovelles doorway, with sandstone ashlars arranged in a radial pattern. On the main floor two openings with perforated architraves can be found. The decorations of the monolithic architraves with perforated transenna on the second floor are larger and more chiaroscuro, where the three windows do not respect the eurythmy. Its construction, within the first half of the 16th century, is due to traveling workers capable of reinventing the traditional decorative motifs for the Catalan families residing in Alghero.