Some open spaces in the city are voids left by the structures around them. Others are figural spaces defined by the surrounding buildings. But there are some urban spaces that seem to fall outside of these alternatives. That seems to be the case of Piazza Rucellai, a small triangular open space in the historic center of Florence.
Piazza Rucellai is defined primarily by Palazzo Rucellai, the canonical building designed by Leon Battista Alberti, one of the preeminent architects and theoreticians of the Renaissance. At Palazzo Rucellai, Alberti's job involved the unification of a number of existing houses into a singular scheme, with a central courtyard and a rigorously composed classical façade. It also included a three-bay open loggia across the street, Via della Vigna Nuova, and perpendicular to the palazzo. This most unusual positioning of the two structures defines a 90-degree angle carving a deeper space in front of the palazzo. And certainly the new façade required quite a bit more perspective than what the width of the street could provide. Then, the buildings along another street coming at an acute angle--curiously named Via del Purgatorio--provide the hypotenuse completing the triangular space.
I must confess that I particularly like these kinds of design operations, as they:
define open space with geometric precision
maintain the discrete entity of the buildings
engage the whole thing within the fabric of the city.
All done in a most unaffected way, almost as if it were easy.