In 1383 Francesco Datini returned to Prato from his long stay in Avignon and immediately began to supervise the building work personally and with great devotion:
“Io sono tanto occupato dal fatto di murare, che io non penso ad altro, né di giorno né di notte; tanta è la voglia che io ho di essere fuori da questo fatto per attendere poi ad altro. E come da Stoldo saprai tra qui e sabato sarà fatta la prima volta”
(Lettera Firenze-Pistoia, 12.4.1383. ASPO, Archivio Datini, 444, cod. 400536).
He was so completely obsessed by his commitment that his friends reprimanded him:
“Non dico che lasci il murare, che fa dimenticare a questi tempi molte cose, ma solo ti prego che non t'affatichi: sta'a vedere. Il desinare e la cena siano all'ore debite [...] e la visita in chiesa, falla”.
(Lettera Firenze-Prato, 9.6.1383. ASPO, Archivio Datini, 325, cod. 1674).
The work undertaken during the first decade involved the entire wing, now designated as a museum.
Dating from this period are the wine cellar, the two frescoed rooms on the ground floor, the courtyard with loggia and well and the kitchen that looked on to it, the room on the upper floor with the connecting inner staircase, the bedroom of Francesco and Margherita above the kitchen, the room where his partner Stoldo slept and the upper loggia, later closed in and turned into a room which is now the entrance to the Archive.
The most significant nucleus of pictorial interventions also dates back to 1391.