Like a signal from the past, Leon Battista Alberti’s De re aedificatoria —On the Art of Building, completed in 1452—transmitted urban-planning concepts of classical antiquity to the Renaissance scholars of 15th century. Today, Alberti’s impact on the field of architecture remains well known, but his abiding influence on traditional urban planning patterns is less appreciated.
In form and substance, Alberti’s work remains inseparable from the work of Vitruvius, the Roman architect whose writings encapsulated the maxims and mysteries of ancient building. For almost five hundred years, Alberti and Vitruvius reigned among the most influential texts in modern European architecture. On the surface, Alberti followed Vitruvius’ structure by dividing his material into ten chapters, mirroring the ancient Ten Books of Architecture. More substantially, his work laid out urban ideas and patterns that Vitruvius had once articulated, concepts which had been largely forgotten by the 15th century.
Alberti was inseparable from the time and places that shaped him. Born in Genoa on Valentine’s Day 1404, his early years were marked by a mixture of privilege and hardship. His father was a merchant from a wealthy Florentine family; in the classic fashion of Florence, he had been exiled from the city since 1393, when political enemies had come to power. Meanwhile, the plague was ravaging Europe. Alberti’s mother, about whom little is known, died during an outbreak in Genoa around 1406, when Alberti was just two years old. The young Alberti grew up with his merchant father, moving frequently, living in Venice and then Padua, and often traveling throughout northern Italy. Alberti was fortunate to receive a first-rate secondary education, shaped by classical studies, at a boarding school in Padua, but shortly after entering university, his father died. Because his parents had never married, family members used his illegitimacy as a pretext to steal his inheritance.
Despite the tragedy and transience of his youth, and the sudden loss of his patrimony, Alberti found many ways to excel. The great Swiss historian of the Italian Renaissance, Jacob Burckhardt, described the young Alberti’s talents and the insatiable curiosity that drove him:
He learned music without a master, and yet his compositions were admired by professional judges. Under the pressure of poverty, he studied both civil and canonical law for many years, till exhaustion brought on a severe illness. In his twenty-fourth year, finding his memory for words weakened, but his sense of facts unimpaired, he set to work at physics and mathematics. And all the while he acquired every sort of accomplishment and dexterity, cross-examining artists, scholars, and artisans of all descriptions, down to the cobblers, about the secrets and peculiarities of their craft.
He was, one might say, a sort of John the Baptist figure for the Renaissance man that would soon become a cliché of Italian masters and strivers alike. He presaged all the essential characteristics: exceptionally well read, he delved into a broad range of arts and sciences with the confidence of an explorer; and he was endlessly intoxicated by the possibilities presented when the secrets of the past were crossed with the boundless potential of the present.
Alberti’s early studies had exposed him to the works of antiquity, and his ties to Florence had placed him, as a young adult, within the orbit of Cosimo di Medici’s passion for rediscovering the classics. The writings of the past had been preserved by Byzantine and Muslim scholars; and to a lesser extent by the cloistered monks of Western Europe. All at once, these texts were being recovered and reinterpreted by the scholars of 15th-century mercantile Italy. Renaissance biographer Giorgio Vasari relates that, early in his career, Alberti distinguished himself in a variety of fields. He studied law and religion, and he painted; but most especially, he made a name for himself in Florence as a writer and an architect.
In 1443, at the age of 38 or 39, Alberti moved to Rome, where he became active in a dizzying period of new construction, spearheaded by Pope Nicholas V  in an ambitious project to remake the city. About the same time, Alberti began work on De re aedificatoria, a project that would continue for much of the next decade. In 2009, Pietro Roccasecca, a scholar today at the Accademia di Belle Arti in Rome, described  Alberti’s work in as intended “not only to update [Vitruvius], but also to go deeper and to put the internal logic of antique architecture to a critical test….Each page is proof of a deep knowledge of philosophical, scientific and historical texts, but he is also just as well acquainted with poetry, literature and rhetoric.”change_me
Strictly speaking, Alberti’s De re aedificatoria is a milestone in the canon of European architecture. But a sizable portion also deals directly with the allied arts of urban planning. Specifically, Alberti provides insights about how planning was practiced in ancient times, as well as his own interpretation of these practices for the 15th century. Sections on site plans and street design remain particularly meaningful, as do discussions about the variety of urban buildings, their arrangement, and their interplay. Much has been written about the continuing influence of Alberti on Western architecture, and about how he served as a vessel for ancient knowledge; but far less attention has been paid to his impact on planning.
Like Vitruvius, Alberti wrote for the scholars and professionals of a confident, ascendant society. Expansion was expected, and his writing was directed at those with the power to shape the terms of growth. Alberti’s approach is fundamentally empirical, a point frequently obscured by his tendency to meander through anecdotes of questionable value from the ancient writers. Also beneath the surface, despite its primary objective to be a definitive text on classical architecture, Alberti’s actual project presents the building blocks of an entire, viable city in the classical tradition. Alberti lays out the most fundamental components of a city’s military, political, and economic viability; he describes the construction methods of defensive walls, towers, and other components of fortification; he articulates a series of organizing principles for neighborhood patterns and street dimensions within those walls; and, only within this broader context, he covers the architecture of various monuments, public and private buildings, and open-air spaces.
[A] city ought to be so placed as to have all sufficient necessaries within its own territory (as far as the condition of human affairs will permit) without being obliged to seek them abroad; and that the circuit of its confines ought to be fortified, that no enemy can easily make an irruption upon them, though at the same time they may send out armies into the countries of their neighbors, whatever the enemy can do to prevent it; which is a situation that they tell us will enable a city not only to defend its liberty, but also to enlarge the bounds of its dominion.
Here Alberti devotes a portion of text to the literal perimeter of urbanism: strategies and methods for defensive walls. Walls (and their associated features, like gates, towers, and moats) remained the norm in the early Renaissance, before advances in artillery (as well as statecraft) began to render them obsolete. Yet the relative permanence of city walls—resulting from the prohibitive labor and expense that go into their construction—means that in the days of their functionality they formed a hard limit to the amount of buildable land within them. As a result, land use efficiency was prioritized in walled cities; and cities that expected to grow were required to account for this in determining the reservation of raw land within the perimeter of newly constructed defenses.
Moving within the city walls, some of the most interesting planning concepts addressed in De re aedificatoria come where Alberti ventures into a mixture of practical and aesthetic theories, drawn from the texts of ancient writers, about large-scale town planning. Addressing the possible variations of street width and curvature, he writes:
Such should be the ways out of the city: short, straight, and secure. When they come to the town, if the city is noble and powerful, the streets should be straight and broad, which carries an air of greatness and majesty; but if it is only a small town or a fortification, it will be better, and as safe, not for the streets to run straight to the gates; but to have them wind about sometimes to the right, sometimes to the left, near the wall, and especially under the towers upon the wall; and within the heart of the town, it will be handsomer not to have them straight, but winding about several ways, backwards and forwards, like the course of a river. For thus, besides that by appearing so much the longer, they will add to the idea of the greatness of the town, they will likewise conduce very much to beauty and convenience and be a greater security against all accidents and emergencies. Moreover, this winding of the streets will make the passenger at every step discover a new structure, and the front and door of every house will directly face the middle of the street; and whereas in larger towns even too much breadth is unhandsome and unhealthy, in a small one it will be both healthy and pleasant, to have such an open view from every house by means of the turn of the street.
Thus, Alberti presages a concept that would be addressed more thoroughly by later major writers on the art of urban planning, including Camillo Sitte  and Raymond Unwin , namely, that irregularity, in certain settings, is both more beautiful and more effective at creating a compelling sense of place than the use of formal, geometric dimensions. Yet on this point Alberti is no zealot. He reserves a prominent place for the formal street: as an avenue into the center of a principal city, designed to showcase the grandeur of its surroundings, and to emphasize the importance of its approach. Thus, he offers a fine-tuned analysis, in a usefully concise passage, crediting the benefits and reciting the drawbacks of competing street typologies in different hypothetical settings. As he does throughout the text, he grounds his conclusions in a combination of logic and the primary sources of ancient writers.
Later, Alberti returns to the layout of neighborhoods to emphasize the importance of physical planning. “The principal ornament of the city,” he writes, “will arise from the disposition of the streets, squares, and public edifices, and their being all laid out and contrived beautifully and conveniently, according to their several uses; for without order, there can be nothing handsome, convenient, or pleasing.” In the same chapter, he also advocates for the concentration of similar merchants in convenient parts of the city; and the segregation of nuisances to the outskirts (with attention paid to the direction of prevailing winds, to minimize the city’s exposure to noxious fumes). Thus, we see that Alberti manifested an early call for rationality as a vital component of urban planning, and not just adherence the micropolitics of incremental growth. He writes that a “city is not built wholly for the sake of shelter … besides mere civil conveniences there may be handsome spaces left for squares, courses for chariots, gardens, places to take the air in, for swimming, and the like, both for ornament and recreation.”
In Alberti’s time, bridges were central features of the built environment in many time-worn Mediterranean cities. Among the bridges in Italy that remain familiar today, and that Alberti would certainly have also known, is the Ponte Vecchio in Florence; ancient bridges like the Ponte Rotto and the Ponte Sant’Angelo in Rome; and the countless unnamed bridges that form the latticework of walkways that skip over the capillary canals of Venice. In a thread similar to his advice about the layout of neighborhoods, Alberti provides basic instructions for the placement of bridges, recommending that they “ought to be at the very heart of the city” and built to be “durable.”
Alberti proceeds to describe several key points about bridge construction, including the ideal materials for the structural components of distinct types of bridges in various settings; a treatment of paving stones and elements of ornamentation; and an extensive discussion of Caesar’s approach to building bridges in the course of his military campaigns.
Keeping with his focus on the details of city-building, Alberti offers salient diversions throughout De re aedificatoria about Western roadbuilding practices from antiquity through his own time. He describes the separation of cartways (that is, the streets) from raised sidewalks: a pattern that was as familiar in the stone thoroughfares of classical Pompeii as it is in the asphalt and concrete canyons of modern cities. Further to this point, he provides instructions about the selection and cobbling of paving stones to provide traction. Alberti also provides a fascinating description of one of history’s earliest divided highways, in his own time, linking central Rome to its ancient seaport at Ostia Antica:
As there is a great concourse of people and great quantities of merchandise brought thither from Egypt, Africa, Libya, Spain, Germany, and the [Mediterranean] islands, the road is made double, and in the middle of it is a row of stones standing up a foot high … to direct the passengers to go on one side and return on the other, so to avoid the inconvenience of meeting one another.
Elsewhere in the text, he addresses topics as varied as the construction methods for both covered and open sewers, and the benefits of each approach; the construction of aqueducts and smaller water mains; the provisions that should be included in the blocks near seaports; and the social importance of parks and squares. Recalling the Appian Way and its extended highway network, he relates:
[The ancient Romans] paved their highways for above a hundred miles round their capital with extreme hard stones, raising solid causeways under them with huge stones all the way. The Appian Way was paved from Rome quite to Brindisi. In many places along their highways we see rocks demolished, mountains levelled, valleys raised, hills cut through, with incredible expense and miraculous labor; works of great use and glory.
Like Vitruvius, Alberti asks the patient reader to suffer a generous serving of pseudoscience. When discussing a process for site selection, for example, he makes frequent detours into the effects of environmental factors on the physical and mental development of inhabitants – as if these purported correlations were as factual and self-evident as the laws of Euclidean geometry. Elsewhere, he discusses phenomena like vapors and spirits, and their effects on civilization, with a similar credulous factuality. To see such material in a more favorable light, we may concede that the lessons contained in these snippets of folk wisdom often display a sliver of truth, because a bright line between acknowledging the maxims of distilled experience and blindly adhering to baseless superstitions is not always easy discernible. And irrespective of their ultimate veracity, these examples illuminate some of the notions that in fact shaped the work of architects and builders in early Renaissance Europe.
Undoubtedly, De re aedificatoria is primarily a book on architecture. (And it is worth recalling that comprehensive urban planning, as a distinct pursuit, rather than a challenge at the intersection of the traditional social arts, is historically a late development.) But Alberti’s decision to build on the work of Vitruvius, combined with his context of architectural instruction in an overall framework of urban viability, mean that his text still speaks to several important aspects of urban planning. Today, as builders in the developing world face the greatest wave of urbanization in world history— and as cities in the developed world struggle to make space for continued growth—Alberti’s work remains a guidebook for those who value the traditions of both classical and post-Renaissance European architecture. It is worth remembering that such architecture was not usually built in a vacuum, but, instead, in communication with an urban environment. And although the importance of things like city walls and the bounty of a fertile, adjacent countryside have been diminished by changes in statecraft and advances in technology, the urban patterns that Alberti described continue to complement a tradition of building that we have inherited from the ancient past. To read Alberti today is to discover an essential link in that long and living tradition.
Theo Mackey Pollack practices law in New Jersey, and is a consultant on urban-planning projects, including Hurricane Sandy recovery. He blogs at legaltowns.com .
This New Urbanism series is supported by a grant from the Richard H. Driehaus Foundation.
(Author’s Note: The 1755 Leone Edition of De re aedificatoria, quoted in this essay, is itself a translation from the 1452 Latin into English. The 1755 text contains conventions of capitalization and punctuation that are not consistent with today’s standard American and/or Commonwealth English. In addition, the translation contains several idiosyncratic spellings of proper names that differ from today’s standard usage. Keeping in mind that the 1755 text is itself a translation, and therefore not the original language of Alberti, to the greatest extent possible, I have updated the language in these quotations to conform to the conventions of standard American English.)