Churches, public buildings, and houses constructed with Romanesque or Gothic architecture, reminicant of northern Italian influence.
The Palazzo Davanzati is a good example of the transition from the
medieval tower house to the Renaissance palace.
Most of the architecture tried to combine utilitarian and aesthetic purposes, because these mercantile elite needed to rebuilt the city from disasters (a flood in the late 1300s) but they wanted to be impressive as well
The Albizzi family supported a lot of artists and cultural icons
Girolamo Savonarola was a preacher who settled in Florence in 1489. He attacked the tyranny of the Medici family in his sermons, and when n 1494, Charles VIII of France invaded Italy, the Medici’s lost power, and Savonarola took control, putting Florence under extremely rigid control. Eventually, Savonarola’s follers turned on him, and he was killed. More on Savonarola: http://www.newadvent.org/cathen/13490a.htm
Art and Science
At this point, most of the artistic products of Florence were in music, and the numerous academies of literature. The Accademia della Crusca compliled the Dictionary. History of the Accademia della Crusca: http://italian.about.com/library/weekly/aa071900a.htm
When the Lorraine family took over Florence, they revived the town's economy, but they also turned Florence more provincial, so it didn’t participate in a thriving international cultural expansion. So Florence’s culture remain unchanged at staid for quite sometime.