Transactions on the Built Environment vol 15, © 1995 WIT Press, www.witpress.com, ISSN 1743-3509
An 'insula' in the third court of Palazzo Vecchio in Florence: identification of medieval pre-existing structures M. Pecchioli, A. Corrado, L. Bardi Dipartimento di Costruzioni, Facolta di Architettura deirUniversita degliStudi, Piazza Brunelleschi n.6, Firenze, Italy
Abstract The reinforcement of a monumental organism is unique only if the evolutionary process of the building unit is known, the history and its rearrangements will show the effective static functioning as well as the inadequacy of certain structural modifications. The research starts by investigating the crack pattern observed on the back of Palazzo Vecchio in Florence, and particularly the damage found on a pillar of the %ade in Via della Ninna. The crack seems to involve the part facing Via dei Leoni and some internal bearing walls. The study is an inspection to best comprehend the structural functioning and analyze which stresses to use in a model, whether numerical or experimental photoelastic. The annotated survey rebuilt the architectural history all around the third court of Palazzo Vecchio, confirmed and supported by iconographic and historical documentations as well as latest essays on the monument. The paper runs over the building phases of the part of palace interested by the damage, noticing two ancient pre-existing structures and their pertinencies, the modifications and inclusions occured during the centuries up to the present setting. 1 Introduction During these past years the identification of a sinking found in the pillar "pl"(fig.l) situated at the ground floor of the via delta Ninna %ade proved the necessity to locate both the functioning of the building elements around the area of the sinking and the interventions that might have caused this crack pattern. The restructuring promoted by the duke Cosimo I during the Renaissance, started by Marco del Tasso and then completed by Giorgio Vasari with the
Transactions on the Built Environment vol 15, © 1995 WIT Press, www.witpress.com, ISSN 1743-3509
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setting up of the Monumental Quarters shows a compact organism. On the contrary this Palace wing offers a very articulated architectural definition composed of gradual inclusions of medieval building units, partly still recognizable, pre-existing to the Arnolfo di Cambio part (1298) facing Piazza della Signoria. A comparison of various investigations revealed some banal dissimilarities which, when analyzed, brought to dispute the structural interpretation which attributed to the corner module a strong bearing function, identifying it as a medieval tower rearranged during the Renaissance: 1) the erroneus position of the monumental portal reveal located on the ground floor between the corner module and the following one going back up towards Via Della Ninna "a"(fig.2). The important opening seemed to be the entrance to the first body of building 'T'(fig.2), but a more precise inspection shows that the portal lets in the second module which represents the extension of a considerable medieval palace owned by an aristocratic family called Manieri. The Manieri building, today completely incorporated in Palazzo Vecchio and never before identified, was bought by the Town Hall in 1335; 2) the pillar "p2"(fig.2) previously recognized as a pre-existing roman element, instead, for ornamental and building characteristcs, looks like those of the Manieri Loggia (fig. 2) and therefore not ranged. The study proceeded with the search of a former setting that would respect the ranges of the pre-existing pilasters, comparing present and past differences in level, materials and technologies in relation to the local history. So it has been possible to discover an entire island built in medieval ages on the space of the third court, with an extraordinary typological variety (palaces, public and private loggias, consortial towers,"domus parvae") and an articulated internal road network. In this way the damage was located between two important palaces (XI-XII cen.) where a road, via dei Manieri, had been for centuries. 2 The facades surrounding the sinking Via della Ninna The prospect (fig. 1) is of bush-hammered stone up to the monumental floor in the way that goes from the corner to the eighth window. From the monumental floor to the top, from the first to the sixth window, the facade is plastered, in the following two modules it is again of bush-hammered stone, though this part was modified when the Salone dei Cinquecento was built (1495). Between the first and the second window a seam wall without toothing V(fig.l) is evident, but it is impossible to establish if the mark persists on higher floors than the first one because of the plastering. Apparently this means that the two parts of the building, determined by the vertical line, were built in different periods. On the third floor, holes over jutties of stone, made for balconies according to the building custom in use during all of the XIV century [1],[2],[3], prove the entire corner was not born after this period even though it follows the Manieri
Transactions on the Built Environment vol 15, © 1995 WIT Press, www.witpress.com, ISSN 1743-3509
Architectural Studies, Materials & Analysis
plaster stone smooth walling base bush hammered stone bush hammered stone XV century rusticated wall
VIA DELIA NINNA figure 1: fagade.
Pi - P7 '. pillars of Manieri's loggia
figure 2: ground floor plan.
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Transactions on the Built Environment vol 15, © 1995 WIT Press, www.witpress.com, ISSN 1743-3509
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complex. A similar separation "y" (fig.l) between the eighth and ninth window rises to the Salone dei Cinquecento first row of windows. From the ninth window to the Arnolfo's nucleus the building shows a very different hanging: a stone smooth walling base with a string-course frame, further up a rusticated wall that calls to mind Palazzo Medici-Riccardi (XV century). Therefore the Manieri palace forms a single building unit between the second and eighth window. Via dei Leoni The part facing Via dei Leoni is marked by a similar discontinuity "z"(fig.2): next to the corner rose a palace with consortial tower which was Manieri and Mancini families' property in 1319 [4]. The area on which the corner was built was a Benincasa "Filipetri" property instead. Anyway the complex is probably coeval with the repositioning of the city walls which took place in this area during the first half of the XI century [5]. Also in this case the corner was clearly built in adherence to the consortial palace and therefore after it. 3 Determination of the Palace's original setting Inside, the part of building in front of Uffizi Gallery, where the church of S. Piero Scheraggio (1066) once stood until the XVI century, shows a very complex stratification on the ground floor: an entrance door to the Manieri building, originally external "b"(fig.2), and a barrel vaults way V(fig.2) start from room "9", lead to the undergrounds of the third court tofind,finally,an exit on Piazza della Signoria (north side). It was established that the passage is connected with the ancient Via di Bellanda and room "9" with a widening facing S. Piero in Scheraggio. The pillars of the church (deconsecrated in 1563), still visible in the entrance of the Gallery, look like those of the Manieri loggia. According to this fact and to the economic development of this part of the city, calling to mind that since the year 1010 the "Carroccio", symbol of the Commune's freedom, was kept in the religious building, the Loggia and the first setting of the Manieri Palace go back to the XI century. The demolition of S. Piero Scheraggio's left nave (1410) was decided in consequence of the fortification of the perimeter of Palazzo Vecchio willed by Duca d'Atene in 1343 [6], when he incorporated the "Platea di Bellanda" via della Ninna became a narrow corridor between the church and the ducal walls (fig.3). During the XV century Antonio del Pollaiolo, called // Cronaca, while building the Salone dei Cinquecento altered the underground, the ground and thefirstfloorin order to create an adequate structure able to support new heightening stresses. So he eliminated completely the wide road on the side, or whatever was left of it. The central core of the Manieri Palace was supplied with a vaulted cellar "m" (fig.4) presently accessible through a staircase built in more recent times. The original entrance from Via della Ninna was about 120 cm. lower than the present one and it is still visible. Room V may be deemed coeval because of conforming building material, though modified to create the foundations for the
Transactions on the Built Environment vol 15, © 1995 WIT Press, www.witpress.com, ISSN 1743-3509
Architectural Studies, Materials & Analysis
ings Manieri s loggia figure 3: Palace original setting at the end of xni century.
figure 4: subsoil plan PI
m section A-A figure 4a: subsoil and ground floor section
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Salone dei Cinquecento, while rooms "q" and V were added afterwards and in their barrel vaults there is a formwork structure. The head of the vault is at an upper level compared to the impost plane of the internal pillar, so that it was necessary to make the loft about 8O cm higher and to hide the base (fig.4a). The street-corner in addition to the two main buildings was made according to the pattern (fig. 5). The complex without it was like (fig. 6). In the sales contract of the Manieri property, bought by the Town Hall in 1335 [7] for 7,000 golden florins, it is said that the palace had been divided into smaller units and the loggia, located on the back and partly discovered in 1975 "p4"-"p$""p&" (fig.2), had been closed and used as "domus parvae". The document describes the entire street-block surrounded by Via della Ninna , Via dei Manieri, Via del Guardingo, Via di Bellanda (fig.3). In this way we learn that Via dei Manieri surely existed until 1335 and the addition illustrated (fig. 6) is posterior, perhaps going back to the Duke of Athen's period (1343) [8]. Finally if we consider that the initial nucleus might have corresponded with the largest underground room and that the Manieri loggia surrounded the building, the result is a pattern like the one (fig. 7). This theory seems to be confirmed by the position of two more pillars "P3"-"P7" (fig.2) of the Loggia on the existing ranging. The ancient setting assumption also seems to be proved by Prey's cadastral rebuilding [9] (Fig,8) and by Stefano Buonsignori's map [10] (fig.9), which shows the third court at the end of the XVI century, before Ammannati's modification: part of via di Bellanda and via dei Manieri is visible. Conclusions At present the corner is mainly alike the vasarian restructuring (1555-1562) whose interventions are now easy to understand: the wall "A"(fig.2/fig.lO) of the 1343 facade still exists on the ground floor, on the mezzanine and on the third floor while on the representative floors (first, second and fourth ones) it was demolished to build the Monumental Quarters. The vaults and lofts of these floors lay on the vasarian "secret staircase" and are therefore coeval to this. According to texts Giorgio Vasari proceeded in order to make "the rooms more airy and proportional", so probably Marco Del Tasso had already demolished the wall of the old facade to create wide rooms even though too low [11]. With the same aim it was also necessary to put up a fairly thick wall "B"(fig.lO) supporting the vaults, part of the lofts and the roof. When the investigation was done the wall which incorporated the pillar "p2" was missing on the ground floor. Observing former planimetries it was possible to discover that it had been eliminated during recent restorations (1975) not being considered a bearing structure since it was next to two other thick walls. This intervention, which modifies substantially its structural behavior, and the concentration of office areas on higher floors, bring new and quite strong solicitations on the facade pillar, as a result this is now unbound from the ranging orthogonal to via della Ninna. The crack pattern is to be attributed mainly to this rash intervention.
Transactions on the Built Environment vol 15, © 1995 WIT Press, www.witpress.com, ISSN 1743-3509
Architectural Studies, Materials & Analysis
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figure 5: setting at the end of xii century
figure 6: setting at 1343
S-i^-
figure 7: setting at the end of xiv century
Transactions on the Built Environment vol 15, © 1995 WIT Press, www.witpress.com, ISSN 1743-3509
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via delta ninna figure 8: Prey's cadastral rebuilding
DELIA figure 9: detail of S. Buonsignori's map
figure 10: second floor plan
References [1] Sznura, F, L'espansione urbana di Firenze nel dugento, La Nuova Italia, Firenze, 1975; [2] Fanelli, G, Firenze, Laterza, Roma - Bari, 1981; [3] Schiaparelli, A., La casafiorentina e i suoi arredi nei secoli XIVe XV, Le Lettere, Firenze 1983. [4] Prow, filza n°16, 26 marzo 1319, Archivio di Stato di Firenze. [5] Villani, G, Cronaca, Firenze, 1823. [6] Prow, filza n°19, 26 aprile 1343, Archivio di Stato di Firenze. [7] Prow, filza n°27, 8 novembre 1335, Archivio di Stato di Firenze. [8] Prow, filza n°32, 10 gennaio 1343, Archivio di Stato di Firenze. [9] Frey, K., Die Loggia del Lanzi, Berlin, 1885. [10] Buonsignori, S., Planivolumentria di Firenze al 1584, Museo di «Firenze Com'era», Firenze. [11] Vasari, G, Ragionamenti di G Vasari con lo 111. Ecc. Don Francesco de' Medici, tomo VIII, Le opere di G. Vasari, Sansoni, Firenze, 1906.
