Much of his life and work is an enigma; what is known for sure is that he trained as a stonecutter and mason and studied under Brunelleschi.
While Fancelli likely designed the Palazzo Pitti, the Florentine residence of the Medici's friend, and supposed rival, Luca Pitti; Vasari attributes the design to Brunelleschi, who had died several years before work began.
Mantua under the Gonzagas was artistic center, employing Pisanello, Mantegna, Perugino, Correggio, Leon Battista Alberti, Giulio Romano, and Rubens.
The Marquess of Mantua Federico I began work on a new royal palace in the city, and Fancelli received the commission to design a complex of rooms for new palace centred on its clock tower, this wing known as the Domus Nova ("New House").
The final years of Fancelli's life are characteristically enigmatic; he disappears from all written references from 1494.