The first phase, probably under the supervision of Ferdinando Tacca, took place over about ten years and comprised a number of modifications in the central body of the building.

In a second phase, between 1670 and 1685, the direction of works passed into the hands of the architect Pier Maria Baldi, who in 1673 was elected chief architect by the Grand-duke Ferdinando II. Baldi designed significant extensions to the fifteenth-century palazzo and of the facade towards the north, implemented following the purchase of various adjacent buildings.
For this ambitious project, it appears that the famous artist Gian Lorenzo Bernini was also consulted, at least for an opinion. Bernini, one of the major architects and sculptors of the Papal court, was in Florence in 1665 as the guest of the Riccardi.
In 1675 Gabbriello Riccardi died. His nephew Francesco continued the work of rebuilding and modification of the palazzo, although aiming decisively now at a lavish and scenographic effect. In line with this taste was the commission offered to the Neapolitan artist Luca Giordano, the greatest Baroque painter of the time, to fresco the ceiling of the galleria and that of the reading-room of the biblioteca (1682-1685).