Italian Renaissance Architecture
Tempietto di San Pietro in Montorio, Rome, 1502, by Bramante. This small temple marks the place where St Peter was put to death.
Tempio di Vesta, Rome, 205 AD. As the most important temple of Ancient Rome, it became the model for Bramante's Tempietto.
Renaissance Architecture is the architecture of the period beginning between the early 15th and the early 17th centuries in different regions of Europe, where there was a conscious revival and development of certain elements of Classical Greek and Roman thought and material culture.
The Renaissance style places emphasis on symmetry, proportion, geometry and the regularity of parts as they are demonstrated in the architecture of Classical antiquity and in particular, the architecture of Ancient Rome, of which many visible examples existed. Orderly arrangements of columns, pilasters and lintels, as well as the use of semicircular arches, hemispherical domes, niches and aedicules replaced the more complex proportional systems and irregular profiles of medieval buildings.
Developed first in Florence, with Filippo Brunelleschi as one of its innovators, the Renaissance style quickly spread to other Italian cities and then to France, Germany, England, Russia and elsewhere.
The word "renaissance" derived from the term "la rinascita" which first appeared in Giorgio Vasari's Vite de' più eccellenti architetti, pittori, et scultori Italiani (The Lives of the Artists, 1550-68).
Although the term Renaissance was used first by the French historian Jules Michelet, was given its more lasting definition from the Swiss historian Jacob Burckhardt, whose book, Die Kultur der Renaissance in Italien 1860,  was influential in the development of the modern interpretation of the Italian Renaissance. The folio of measured drawings Édifices de Rome moderne; ou, Recueil des palais, maisons, églises, couvents et autres monuments (The Buildings of Modern Rome), first published in 1840 by Paul Letarouilly, also played an important part in the revival of interest in this period.  The Renaissance style was recognized by contemporaries in the term “all'antica,” or "in the ancient manner (of the Romans)".
Historians often divide the Renaissance in Italy into three phases.  Whereas art historians might talk of an "Early Renaissance" period, in which they include developments in 14th century painting and sculpture, this is usually not the case in architectural history. The bleak economic conditions of the late 14th century did not produce buildings that are considered to be part of the Renaissance. As a result, the word "Renaissance" among architectural historians usually applies to the period 1400 to ca. 1525, or later in the case of non-Italian Renaissances.
Historians often use the following designations:
Renaissance (ca. 1400-1500); also known as the Quattrocento. and sometimes Early Renaissance
High Renaissance Cinquecento (ca.1500-1525)
Mannerism (ca. 1520-1600)
In the Quattrocento, concepts of architectural order were explored and rules were formulated. The study of classical antiquity led in particular to the adoption of Classical detail and ornamentation.
Space, as an element of architecture, was utilised differently to the way it had been in the Middle Ages. Space was organised by proportional logic, its form and rhythm subject to geometry, rather than being created by intuition as in Medieval buildings. The prime example of this is the Pazzi Chapel in Florence by Filippo Brunelleschi (1377-1446).
During the High Renaissance, concepts derived from classical antiquity were developed and used with greater surety. The most representative architect is Donato Bramante (1444-1514) who expanded the applicability of classical architecture to contemporary buildings. His San Pietro in Montorio (1503) was directly inspired by circular Roman temples. He was, however, hardly a slave to the classical forms and it was his style that was to dominate Italian architecture in the 16th century.
During the Mannerist period, architects experimented with using architectural forms to emphasize solid and spatial relationships. The Renaissance ideal of harmony gave way to freer and more imaginative rhythms. The best known architect associated with the Mannerist style was Michelangelo (1475-1564), who is credited with inventing the giant order, a large pilaster that stretches from the bottom to the top of a facade. He used this in his design for the Campidoglio in Rome.
Another leading example of the Mannerist approach is the Palazzo Te (1524-1534) by Giulio Romano in Mantua with its monumental loggias, rusticated walls, garden grottoes and extensive frescos. Prior to the 20th century, the term Mannerism had negative connotations, but it is now used to describe the historical period in more general non-judgemental terms.
As the new style of architecture spread out from Italy, most other European countries developed a sort of proto-Renaissance style, before the construction of fully formulated Renaissance buildings. Each country in turn then grafted its own architectural traditions to the new style, so that Renaissance buildings across Europe are diversified by region.
Within Italy the evolution of Renaissance architecture into Mannerism, with widely diverging tendencies in the work of Michelangelo and Giulio Romano and Andrea Palladio, led to the Baroque style in which the same architectural vocabulary was used for very different rhetoric.
Outside Italy, Baroque architecture was more widespread and fully developed than the Renaissance style, with significant buildings as far afield as Mexico and the Philippines. It is the subject of a separate article.
The Dome of St. Peter's Basilica, Rome. photo- Wolgang Stuck, 2004
Renaissance Architectural Theory
During the Renaissance, architecture became not only a question of practice, but also a matter for theoretical discussion. The first treatise on architecture was De re aedificatoria (English: On the Art of Building) by Leon Battista Alberti in 1450. It was to some degree dependent on Vitruvius' De architectura, a manuscript of which was discovered in 1414 in a library in Switzerland. De re aedificatoria in 1485 became the first printed book on architecture. Printing played a large role in the dissemination of ideas. Sebastiano Serlio (1475 – c. 1554) produced the next important text, the first volume of which appeared in Venice in 1537; it was entitled "Regole generali d'architettura [...]" (or "General Rules of Architecture"). It is known as Serlio's "Fourth Book" since it was the fourth in Serlio's original plan of a treatise in seven books. In all, five books were published. In 1570, Andrea Palladio (1508 –1580) published I Quattro Libri dell'Architettura (The Four Books of Architecture) in Venice. This book was widely printed and responsible to a great degree of spreading the ideas of the Renaissance through Europe. All these books were intended to be read and studied not only by architects, but also by patrons.
Characteristics of Renaissance architecture
Sant'Agostino, Rome, Giacomo di Pietrasanta, 1483
The obvious distinguishing features of Classical Roman architecture were adopted by Renaissance architects. However, the forms and purposes of buildings had changed over time. So had the structure of cities. Among the earliest buildings of the reborn Classicism were churches of a type that the Romans had never constructed. Neither were there models for the type of large city dwellings required by wealthy merchants of the 15th century. Conversely, there was no call for enormous sporting fixtures and public bath houses such as the Romans had built. The ancient orders were analysed and reconstructed to serve new purposes.
The list of characteristics below is based on Banister Fletcher's History of Architecture on the Comparative Method.
The plans of Renaissance buildings have a square, symmetrical, planned appearance in which proportions are usually based on a module. Within a church the module is often the width of an aisle.
Facades are symmetrical around their vertical axis. Church facades are generally surmounted by a pediment. The columns and windows show a progression towards the center. Domestic buildings are often surmounted by a cornice. There is a regular repetition of openings on each floor, and the centrally placed door is marked by a feature such as a balcony, or rusticated surround.
Classical Orders, engraving from the Encyclopédie vol. 18. 18th century.
The Roman orders of columns are used:- Tuscan, Doric, Ionic, Corinthian and Composite. The orders can either be structural, supporting an arcade or architrave, or purely decorative, set against a wall. When against walls, the orders often appear as pilasters.
Arches are semi-circular or (in the Mannerist style) segmental. Arches are often used in arcades, supported on piers or columns with capitals. There may be a section of entablature between the capital and the springing of the arch.
Vaults do not have ribs. They are semi-circular or segmental and on a square plan, unlike the Gothic vault which is frequently rectangular.
The Dome is used frequently, both as a very large structural feature that is visible from the exterior, and also as a means of roofing smaller spaces where they are only visible internally.
Roofs are fitted with flat or coffered ceilings. They are not left open as in Medieval architecture. They are frequently painted or decorated.
Courtyard of Palazzo Strozzi, Florence
Door usually have square lintels. They may be set within an arch or surmounted by a triangular or segmental pediment. Openings that do not have doors are usually arched and frequently have a large or decorative keystone.
Windows may be paired and set within a semi-circular arch. They may have square lintels and triangular or segmental pediments, which are often used alternately. In the Mannerist period the “Palladian” arch was employed, using a motif of a high semi-circular topped opening flanked with two lower square-topped openings. Windows are used to bring light into the building. Stained glass does not feature.
External walls are generally of highly-finished ashlar masonry, laid in straight courses. The corners of buildings are often emphasised by rusticated “quoins”. Basements are often rusticated. Internal walls are smoothly plastered. Internal surfaces are often decorated with frescoes.
Courses, moldings and all decorative details are carved with great precision. Moldings stand out around doors and windows rather than being recessed. Sculptured figures may be set in niches or placed on plinths. They are not integral to the building as in Medieval architecture. 
Influences on the development of Renaissance architecture in Italy
Italy of the 15th century, and the city of Florence in particular, was home to the Renaissance. It is in Florence that the new architectural style had its beginning, not slowly evolving in the way that Gothic grew out of Romanesque, but consciously brought to being by particular architects who sought to revive the order of a past "Golden Age". The scholarly approach to the architecture of the ancient coincided with the general revival of learning. A number of factors were influential in bringing this about.
The Romanesque Baptistry (at Florence Cathedral) of Florence was the object of Brunelleschi's studies of perspective
Italy had never fully adopted the Gothic style of architecture. Apart from the Cathedral of Milan, largely the work of German builders, few Italian churches show the emphasis on vertically, the clustered shafts, ornate tracery and complex ribbed vaulting that characterise Gothic in other parts of Europe. Italian architects had always preferred forms that were clearly defined and structural members that expressed their purpose. The presence, particularly in Rome, of architectural remains showing the ordered Classical style provided an inspiration to artists at a time when philosophy was also turning towards the Classical.
In the 15th century, Florence, Venice and Naples extended their power through much of the area that surrounded them, making the movement of artists possible. This enabled Florence to have significant artistic influence in Milan, and through Milan, France.
In 1377 the Pope from Avignon and re-established of the Papal court in Rome, bringing a renewal in the importance of the Pope in Italy, further strengthened by the Council of Constance in 1417. and also in the wealth and importance of Rome. Successive Popes, especially Julius II, 1503-13, sought to extend the Pope’s temporal power throughout Italy. 
In the early Renaissance, Venice controlled sea trade over goods from the East. The large towns of Northern Italy were prosperous through trade with the rest of Europe, Genoa providing a seaport for the goods of France and Spain; Milan and Turin being centers of overland trade, and maintaining substantial metalworking industries. Trade brought wool from England to Florence, ideally located on the river for the production of fine cloth, the industry on which its wealth was founded. By dominating Pisa, Florence gained a seaport, and also maintained dominance of Genoa. In this commercial climate, one family in particular turned their attention from trade to the lucrative business of money-lending. The Medici became the chief bankers to the princes of Europe, becoming virtually princes themselves as they did so, by reason of both wealth and influence. Along the trade routes, and thus offered some protection by commercial interest, moved not only goods but also artists, scientists and philosophers.
Pope Sixtus IV, 1477, builder of the Sistine Chapel. Fresco by Melozzo da Forli in the Vatican Palace.
The return of the Pope from Avignon in 1377 and the resultant the new emphasis on Rome as the center of Christian spirituality, brought about a boom in the building of churches in Rome such as had not taken place for nearly a thousand years. This commenced in the mid 15th century and gained momentum in the 16th century, reaching its peak in the Baroque period. The construction of Sistine Chapel with its uniquely important decorations and the entire rebuilding of St Peter's, one of Christendom's most significant churches, was part of this process.
In wealthy republican Florence, the impetus for church-building was more civic than spiritual. The unfinished state of the enormous cathedral dedicated to the Blessed Virgin Mary did no honour to the city under her patronage. However, as the technology and finance were found to complete it, the rising dome did credit not only to the Blessed Virgin, its architect and the Church but also the Signoria, the Guilds and the sectors of the city from which the manpower to construct it was drawn. The dome inspired further religious works in Florence.
Four Humanist philosophers under the patronage of the Medici: Marsilio Ficino, Cristoforo Landino, Angelo Poliziano and Demetrius Chalcondyles. Fresco by Domenico Ghirlandaio.
The development of printed books, the rediscovery of ancient writings, the expanding of political and trade contacts and the exploration of the world all increased knowledge and the desire for education.
The reading of philosophies that were not based in Christian theology led to the development of Humanism through which it was clear that while God had established and maintained order in the Universe, it was the role of Man to establish and maintain order in Society.
Cosimo de' Medici the Elder, head of the Medici Bank, sponsored civic building programs. Fresco by Bronzino.
Through Humanism, civic pride and the promotion of civil peace and order were seen as the marks of citizenship. This led to the building of structures such as Brunelleschi's Hospital of the Innocents with its elegant colonnade forming a link between the charitable building and the public square, and the Laurentian Library where the collection of books established by the Medici family could be consulted by scholars.
Some major ecclesiastical building works were also commissioned, not by the church, but by guilds representing the wealth and power of the city. Brunelleschi’s dome at Florence Cathedral, more than any other building belonged to the people of the city because the construction of each of the eight segments was achieved by a different sector of the city.
As in the Platonic academy of Athens, it was seen by those of Humanist understanding that those people who had the benefit of wealth and education ought to promote the pursuit of learning and the creation of that which was beautiful. To this end, wealthy families:- the Medici in Florence, the Gonzaga family of Mantua, the Farnese in Rome, the Sforzas in Milan, gathered around them people of learning and talent, promoting the skills and creating employment for the most talented artists and architects of their day. 
Development of Renaissance architecture in Italy
Ospedale Degli Innocenti in Florence.
Early Renaissance, or Quattrocento
The leading architects of the Early Renaissance were Brunelleschi, Michelozzo and Alberti.
The person generally credited with bringing about the Renaissance view of architecture is Filippo Brunelleschi , (1377-1446). The underlying feature of the work of Brunelleschi was "order".
In the early 1400s Brunelleschi began to look at the world to see what the rules were that governed ones way of seeing. His observed that the way one sees regular structures such as the Baptistery of Florence and the tiled pavement surrounding it follows a mathematical order- linear perspective.
The buildings remaining among the ruins of ancient Rome appeared to respect a simple mathematical order in the way that Gothic buildings did not. One incontrovertible rule governed all Ancient Roman architecture- a semi-circular arch is exactly twice as wide as it is high. A fixed proportion with implications of such magnitude occurred nowhere in Gothic architecture. A Gothic pointed arch could be extended upwards or flattened to any proportion that suited the location. Arches of differing angles frequently occurred within the same structure. No set rules of proportion applied.
The dome of Basilica di Santa Maria del Fiore (Florence Cathedral).
From the observation of the architecture of Rome came a desire for symmetry and careful proportion in which the form and composition of the building as a whole and all its subsidiary details have fixed relationships, each section in proportion to the next, and the architectural features serving to define exactly what those rules of proportion are.
Cathedral of Florence
Brunelleschi's first major architectural commission was for the enormous brick dome which covers the central space that of Florence's cathedral, designed by Arnolfo di Cambio in the 14th century but left unroofed. While often described as the first building of the Renaissance, Brunelleschi's daring design utilizes the pointed Gothic arch and Gothic ribs. It seems certain, however, that while stylistically Gothic, in keeping with the building it surmounts, the dome is in fact structurally influenced by the great dome of Ancient Rome, which Brunelleschi could hardly have ignored in seeking a solution. This is the dome of the Pantheon, a circular temple, now a church.
The church of San Lorenzo. Photo Stephan Bauer.
Inside the Pantheon's single-shell dome of brick and stone is coffering which greatly decreases the weight, while maintaining the strength of each individual stone. The vertical partitions of the coffering effectively serve as ribs, although this feature does not dominate visually. At the apex of the Pantheon's dome is an opening, 8 meters across. Brunelleschi was aware that a dome of enormous proportion could in fact be engineered without a keystone. The dome in Florence is supported by the eight large ribs and sixteen more internal ones holding a brick shell, with the bricks arranged in a herringbone manner. Although the techniques employed are different, in practice both domes comprise a thick network of ribs supporting very much lighter and thinner infilling. And both have a large opening at the top.
The new architectural philosophy is best demonstrated in the churches of San Lorenzo and San Spirito in Florence. Designed by Brunelleschi in about 1425 and 1428 respectively, both have the shape of the Latin cross. Each has a modular plan, each portion being a multiple of the square bay of the aisle. This same formula controlled also the vertical dimensions. In the case of Santo Spirito, which is entirely regular in plan, transepts and chancel are identical, while the nave is an extended version of these. In 1434 Brunelleschi designed the first Renaissance central planned building, Santa Maria degli Angeli of Florence. It is composed of a central octagon surrounded by a circuit of eight smaller chapels. From this date onwards numerous churches were built in variations of these designs. 
Palazzo Medici Riccardi by Michelozzo.
Michelozzo Michelozzi, (1396-1472), was an architect under the patronage of the Medici family, his most famous work being the Palazzo Medici Riccardi, which he was commissioned to design for Cosimo de'Medici in 1444. A decade later he built the Villa Medici at Fiesole. Among his other works for Cosimo are the library at the Convent of San Marco, Florence. He went into exile in Venice for a time with his patron. He was one of the first architects to work in the Renaissance style outside Italy, building a palace at Dubrovnik.
The Palazzo Medici Riccardi is Classical in the details of its pedimented window and recessed doors, but, unlike the works of Brunelleschi and Alberti, there are no orders of columns in evidence. Instead, Michelozzo has respected the Florentine liking for rusticated stone. He has seemingly created three orders out of the three defined rusticated levels, the whole being surmounted by an enormous Roman-style cornice which juts out over the street by 2.5 meters.
Leon Battista Alberti, (1402-1472), was an important Humanist theoretician and designer whose book on architecture De re Aedificatoria was to have lasting effect. An aspect of Humanism was an emphasis of the anatomy of nature, in particular the human form, a science first studied by the Ancient Greeks. Humanism made man the measure of things. Alberti perceived the architect as a person with great social responsibilities.
Sant'Andrea, Mantua, the facade. Photo- Frode Inge Helland
He designed a number of buildings, but unlike Brunellleschi, he did not see himself as a builder in a practical sense and so left the supervision of the work to others. Miraculously, one of his greatest designs, that of the Church of Sant'Andrea in Mantua, was brought to completion with its character essentially intact. Not so the church of San Francesco in Rimini, a rebuilding of a Gothic structure, which, like Sant'Andrea, was to have a façade reminiscent of a Roman triumphal arch. This was left sadly incomplete.
Sant'Andrea is an extremely dynamic building both without and within. Its triumphal façade is marked by extreme contrasts. The projection of the order of pilasters that define the architectural elements, but are essentially non-functional, is very shallow. This contrasts with the gaping deeply recessed arch which makes a huge portico before the main door. The size of this arch is in direct contrast to the two low square-topped openings that frame it. The light and shade play dramatically over the surface of the building because of the shallowness of its mouldings and the depth of its porch. In the interior Alberti has dispensed with the traditional nave and aisles. Instead there is a slow and majestic progression of alternating tall arches and low square doorways, repeating the "triumphal arch" motif of the façade.
Façade of S. Maria Novella, 1456-70.
Two of Alberti’s best known buildings are in Florence, the Palazzo Rucellai and at S. Maria Novella. For the palace, Alberti applied the classical orders of columns to the façade on the three levels, 1446-51. At Santa Maria Novella he was commissioned to finish the decoration of the façade. He completed the design in 1456 but the work was not finished until 1470.
In the late 15th century and early 16th century architects such as Bramante, Antonio da Sangallo the Younger and others showed a mastery of the revived style and ability to apply it to buildings such as churches and city palazzo which were quite different to the structures of ancient times. The style became more decorated and ornamental, statuary, domes and cupolas becoming very evident. The architectural period is known as the "High Renaissance" and coincides with the age of Leonardo, Michelangelo and Raphael.
Santa Maria delle Grazie, Milan.
Donato Bramante, (1444-1514), was born in Urbino and turned from painting to architecture, found his first important patronage under Ludovico Sforza, Duke of Milan, for whom he produced a number of buildings over 20 years. After the fall of Milan to the French in 1499, Bramante travelled to Rome where he achieved great success under papal patronage.
Bramante’s finest architectural achievement in Milan is his addition of crossing and choir to the abbey church of Santa Maria delle Grazie. This is a brick structure, the form of which owes much to the Northern Italian tradition of square domed baptisteries. The new building is almost centrally planned, except that, because of the site, the chancel extends further than the transept arms. The hemispherical dome, of approximately 20 metres across, rises up hidden inside an octagonal drum pierced at the upper level with arched classical openings. The whole exterior has delineated details decorated with the local terracotta ornamentation.
In Rome Bramante created what has been described as "a perfect architectural gem", the Tempietto in the Cloister of San Pietro in Montorio. This small circular temple marks the spot where St Peter was martyred and is thus the most sacred site in Rome. The building adapts the style apparent in the remains of the Temple of Vesta, the most sacred site of Ancient Rome. It is enclosed by and in spatial contrast with the cloister which surrounds it. As approached from the cloister, as in the picture above, it is seen framed by an arch and columns, the shape of which are echoed in its free-standing form.
Bramante went on to work at the Vatican where he designed the impressive Cortili of St. Damaso and of the Belvedere. In 1506 Bramante’s design for Pope Julius II’s rebuilding of St. Peter’s Basilica was selected, and the foundation stone laid. After Bramante’s death and many changes of plan, Michelangelo, as chief architect, reverted to something closer to Bramante’s original proposal. See below- Michelangelo. 
Antonio da Sangallo the Younger, (1485-1546), was one of a family of military engineers. His uncle, Giuliano da Sangallo was one of those who submitted a plan for the rebuilding of St Peter’s and was briefly a co-director of the project, with Raphael. Antonio da Sangallo also submitted a plan for St Peter’s and became the chief architect after the death of Raphael, to be succeeded himself by Michelangelo.
The Farnese Palace, Rome (1534-1545). Designed by Sangallo and Michelangelo.
His fame does not rest upon his association with St Peter’s but in his building of the Farnese Palace, “the grandest palace of this period”, started in 1530. The impression of grandness lies in part in its sheer size, (56 m long by 29.5 meters high) and in its lofty location overlooking a broad piazza. It is also a building of beautiful proportion, unusual for such a large and luxurious house of the date in having been built principally of stuccoed brick, rather than of stone. Against the smooth pink-washed walls the stone quoins of the corners, the massive rusticated portal and the stately repetition of finely-detailed windows give a powerful effect, setting a new standard of elegance in palace-building. The upper of the three equally-sized floors was added by Michelangelo. It is probably just as well that this impressive building is of brick; the travetine for its architectural details came not from a quarry, but from the Colosseum.
Raphael, (1483-1520), Urbino, trained under Perugino in Perugia before moving to Florence, was for a time the chief architect for St. Peter’s, working in conjunction with Antonio Sangallo. He also designed a number of buildings, most of which were finished by others. His single most influential work is the Palazzo Pandolfini in Florence with its two stories of strongly articulated windows of a "tabernacle" type, each set around with ordered pilasters, cornice and alternate arched and triangular pediments. 
Mannerism was marked by widely diverging tendencies in the work of Michelangelo, Giulio Romano, Peruzzi and Andrea Palladio, that led to the Baroque style in which the same architectural vocabulary was used for very different rhetoric.
Palazzo Massimo alle Colonne.
Baldassare Peruzzi, (1481-1536), was an architect born in Siena, but working in Rome, whose work bridges the High Renaissance and the Mannerist. His Villa Farnesiana of 1509 is a very regular monumental cube of two equal stories, the bays being strongly articulated by orders of pilasters. The building is unusual for its frescoed walls. 
Peruzzi’s most famous work is the Palazzo Massimo alle Colonne in Rome. The unusual features of this building are that its façade curves gently around a curving street. It has in its ground floor a dark central portico running parallel to the street, but as a semi enclosed space, rather than an open loggia. Above this rise three undifferentiated floors, the upper two with identical small horizontal windows in thin flat frames which contrast strangely with the deep porch, which serving, from the time of its building, as a refuge to the city’s poor.
Giulio Romano (1499-1546), was a pupil of Raphael, assisting him on various works for the Vatican. Romano was also a highly inventive designer, working for Federico II Gonzaga at Mantua on the Palazzo Te, a project which combined his skills as architect, sculptor and painter. In this work he uses illusionistic effects, surprising combination of architectural form and texture and the frequent use of features that seem somewhat disproportionate or out of alignment. The total effect is eerie and disturbing. Ilan Rachum cites Romano as “one of the first promoters of Mannerism” 
Michelangelo Buonarroti (1475-1564), was one of the creative giants whose achievements mark the High Renaissance. He excelled in each of the fields of painting, sculpture and architecture and his achievements brought about significant changes in each area. His architectural fame lies chiefly in two buildings:- the interiors of the Laurentian Library and its lobby at the monastery of San Lorenzo in Florence, and the Basilica of St. Peter in Rome.
St. Peter's of Rome
St Peter's was "the greatest creation of the Renaissance", and a great number of architects contributed their skills to it. But at its completion, there was more of Michelangelo’s design than of any other architect, before or after him. The plan that was accepted at the laying of the foundation stone in 1506 was that by Bramante. Various changes in plan occurred in the series of architects that succeeded him, but Michelangelo, when he took over the project in 1546, reverted to Bramante’s Greek-cross plan and redesigned the piers, the walls and the dome, giving the lower weight-bearing members massive proportions and eliminating the encircling aisles from the chancel and identical transept arms. Helen Gardner says: "Michelangelo, with a few strokes of the pen, converted its snowflake complexity into a massive, cohesive unity." 
Michelangelo’s dome was a masterpiece of design using two masonry shells, one within the other and crowned by a massive lantern supported, as at Florence, on ribs. For the exterior of the building he designed a giant order which defines every external bay, the whole lot being held together by a wide cornice which runs unbroken like a rippling ribbon around the entire building.
There is a wooden model of the dome, showing its outer shell as hemispherical. When Michelangelo died in 1564, the building had reached the height of the drum. The architect who succeeded Michelangelo was Giacomo della Porta. The dome, as built, has a much steeper projection than the dome of the model. It is generally presumed that it was della Porta who made this change to the design, to lessen the outward thrust. But, in fact it is unknown who it was that made this change, and it equally possible, and in fact a stylistic likelihood that the person who decided upon the more dynamic outline was Michelangelo himself, at some time during the years that he supervised the project.
The vestibule of the Laurentian Library.
Michelangelo was at his most Mannerist in the design of the vestibule of the Laurentian Library, also built by him to house the Medici collection of books at the convent of San Lorenzo in Florence, the same San Lorenzo’s at which Brunelleschi had recast church architecture into a Classical mold and established clear formula for the use of Classical orders and their various components.
Michelangelo takes all Brunelleschi’s components and bends them to his will. The Library is upstairs. It is a long low building with an ornate wooden ceiling, a matching floor and crowded with corrals finished by his successors to Michelangelo’s design. But it is a light room, the natural lighting streaming through a long row of windows that appear positively crammed between the order of pilasters that march along the wall. The vestibule, on the other hand, is tall, taller than it is wide and is crowded by a large staircase that pours out of the library in what Pevsner refers to as a “flow of lava”, and bursts in three directions when it meets the balustrade of the landing. It is an intimidating staircase, made all the more so because the rise of the stairs at the center is steeper than at the two sides, fitting only eight steps into the space of nine.
The space is crowded and it is to be expected that the wall spaces would be divided by pilasters of low projection. But Michelangelo has chosen to use paired columns, which, instead of standing out boldly from the wall, he has sunk deep into recesses within the wall itself. In San Lorenzo's church nearby, Brunelleschi used little scrolling console brackets to break the strongly horizontal line of the course above the arcade. Michelangelo has borrowed Brunelleschi’s motifs and stood each pair of sunken columns on a pair of twin console brackets. Pevsner says the “Laurenziana… reveals Mannerism in its most sublime architectural form”.  
Il Gesù, designed by Giacomo della Porta.
Giacomo della Porta
Giacomo della Porta, (c.1533-1602), was famous as the architect who made the dome of St Peter’s Basilica a reality. The change in outline between the dome as it appears in the model and the dome as it was built, has brought about speculation as to whether the changes originated with della Porta or with Michelangelo himself.
Della Porta spent nearly all his working life in Rome, designing villas, palazzi and churches in the Mannerist style. One of his most famous works is the façade of the Church of il Gesù, a project that he inherited from his teacher Vignola. Most characteristics of the original design are maintained, subtly transformed to give more weight to the central section, where della Porta uses, among other motifs, a low triangular pediment overlaid on a segmental one above the main door. The upper storey and its pediment give the impression of compressing the lower one. The center section, like that of Sant'Andrea at Mantua, is based on the Triumphal Arch, but has two clear horizontal divisions like Santa Maria Novella. See Alberti above. The problem of linking the aisles to the nave is solved using Alberti’s scrolls, in contrasts to Vignola’s solution which provided much smaller brackets and four statues to stand above the paired pilasters, visually weighing down the corners of the building. The influence of the design may be seen in Baroque churches throughout Europe.
Villa Capra, or Villa Rotunda
Andrea Palladio, (1518-80), "the most influential architect of the whole Renaissance"', was, as a stone mason, introduced to Humanism by the poet Giangiorgio Trissino. His first major architectural commission was the rebuilding of the Basilica Palladiana at Vicenza, in the Veneto where he was to work most of his life. 
Palladio was to transform the architectural style of both palaces and churches by taking a different perspective on the notion of Classicism. While the architects of Florence and Rome looked to structures like the Coliseum and the Arch of Constantine to provide formulae, Palladio looked to classical temples with their simple peristyle form. When he used the “triumphal arch” motif of a large arched opening with lower square-topped opening on either side, he invariably applied it on a small scale, such as windows, rather than on a large scale as Alberti used it at Sant’Andrea’s. This Ancient Roman motif  is often referred to as the Palladian Arch.
The best known of Palladio’s domestic buildings is the Villa Capra, otherwise known as "la Rotonda", a centrally planned house with a domed central hall and four identical facades, each with a temple-like portico like that of the Pantheon in Rome. 
Like Alberti, della Porta and others, in the designing of a church facade, Palladio was confronted by the problem of visually linking the aisles to the nave while maintaining and defining the structure of the building. Palladio’s solution was entirely different to that employed by della Porta. At the church of San Giorgio Maggiore in Venice he overlays a tall temple, its columns raised on high plinths, over another low wide temple façade, its columns rising from the basements and its narrow lintel and pilasters appearing behind the giant order of the central nave. 
Progression from Early Renaissance through to Baroque
In Italy, there appears to be a seamless progression from Early Renaissance architecture through the High Renaissance and Mannerist to the Baroque style. Pevsner comments about the vestibule of the Laurentian Library that it "has often been said that the motifs of the walls show Michelangelo as the father of the Baroque".
While continuity may be the case in Italy, it was not necessarily the case elsewhere. The adoption of the Renaissance style of architecture was slower in some areas than in others, as may be seen in England, for example. Indeed, as Pope Julius II was having the ancient Basilica of St. Peter’s demolished to make way for the new, Henry VII of England was adding a glorious new chapel in the Perpendicular Gothic style to Westminster Abbey.
Likewise, the style that was to become known as Baroque evolved in Italy in the early 1600s, at about time that the first fully Renaissance buildings were constructed at Greenwich and Whitehall in England, after a prolonged period of experimentation with Classical motifs applied to local architectural forms, or conversely, the adoption of Renaissance structural forms in the broadest sense with an absence of the formulae that governed their use. While the English were just discovering what the rules of Classicism were, the Italians were experimenting with methods of breaking them. In England, following the Restoration of the Monarchy in 1660, the architectural climate had changed, and taste moved in the direction of the Baroque. Rather than evolving, as it did in Italy, it arrived, fully fledged.
In a similar way, in many parts of Europe that had few purely classical and ordered buildings like Brunelleschi’s Santo Spirito and Michelozzo’s Medici Riccardi Palace, Baroque architecture appeared almost unheralded, on the heels of a sort of Proto-Renaissance local style. The spread of the Baroque and its replacement of traditional and more conservative Renaissance architecture was particularly apparent in the building of churches as part of the Counter Reformation.
Spread of Renaissance architecture
Scuola Grande di San Marco, Venice.
Having its origins in Florence, the Renaissance spread throughout Tuscany, to Lombardy, Rome and beyond. In 1499 the French captured Milan causing Bramante to flee to Rome, where he studied ancient ruins, and with these in mind designed some of the most important buildings of the High Renaissance period.  Alberti, one of the pioneers of Renaissance architecture designed his most notable works in Mantua. In Venice, San Zaccaria received its Renaissance facade at the hands of Antonio Gambello and Mauro Codussi, begun in the 1480s.
In general, the courts of most of the lesser Italian states were centers for spreading of Renaissance philosophy, art and architecture. The Renaissance flourished at the famous Ducal Palace at Urbino, at Ferrara with the Este Castle and Palazzo dei Diamanti and under the Visconti in Milan at Certosa di Pavia and under the Sforza at Castello Sforzesco.
In southern Italy, Renaissance masters were called to Naples by Alfonso V of Aragon after his conquest of the Kingdom of Naples. The most notable examples of Renaissance architecture in that city are the Cappella Caracciolo, attributed to Bramante, and the Palazzo Orsini di Gravina, built by Gabriele d'Angelo between 1513 and 1549.
|Between the 14th and the 16th Centuries there was the
stirrings of a new cultural movement which came to be known as the
Renaissance, literally the “Rebirth”, because it revived and developed
certain elements of Classical Greek and Roman thought and material culture.
The cities of Italy in the early 1400s and Florence in particular were
centres of the development of the burgeoning Humanist ideas. This period is
also known in Italy as the Quattrocento.
In none of the arts more than Architecture was this “rebirth” more apparent. The elements for the rediscovery of the Classical were visible in the many ancient buildings which over the centuries had been recycled and used as quarries for their materials.
The Renaissance brought a new emphasis on rational clarity and with it a conscious revival of Roman Architecture with its symmetry, its mathematical proportions, geometrically-perfect designs and regularity of parts. Orderly arrangements of columns and lintels, regularly divided surfaces, semicircular arches and hemispherical domes replaced the haphazard proportions and irregular gabled facades which preceded the new style. It was recognised by contemporaries in the term all'Antica, "in the Antique manner".