Architecture, the practice of building design and its resulting products; customary usage refers only to those designs and structures that are culturally significant. Architecture is to building as literature is to the printed word. Vitruvius, a 1st-century BC Roman, wrote encyclopedically about architecture, and the English poet Sir Henry Wotton was quoting him in his charmingly phrased dictum: "Well building hath three conditions: Commoditie, Firmenes, and Delight." More prosaically, one would say today that architecture must satisfy its intended uses, must be technically sound, and must convey aesthetic meaning. But the best buildings are often so well constructed that they outlast their original use. They then survive not only as beautiful objects, but as documents of the history of cultures, achievements in architecture that testify to the nature of the society that produced them. These achievements are never wholly the work of individuals. Architecture is a social art.
Architectural form is inevitably influenced by the technologies applied, but building technology is conservative and knowledge about it is cumulative. Precast concrete, for instance, has not rendered brick obsolete. Although design and construction have become highly sophisticated and are often computer directed, this complex apparatus rests on preindustrial traditions inherited from millennia during which most structures were lived in by the people who erected them. The technical demands on building remain the elemental ones-to exclude enemies, to circumvent gravity, and to avoid discomforts caused by an excess of heat or cold or by the intrusion of rain, wind, or vermin. This is no trivial assignment even with the best modern technology.
The availability of suitable materials fostered the crafts to exploit them and influenced the shapes of buildings. Large areas of the world were once forested, and their inhabitants developed carpentry. Although it has become relatively scarce, timber remains an important building material.
Many kinds of stone lend themselves to building. Stone and marble were chosen for important monuments because they are incombustible and can be expected to endure. Stone is also a sculptural material; stone architecture was often integral with stone sculpture. The use of stone has declined, however, because a number of other materials are more amenable to industrial use and assembly.
Some regions lack both timber and stone; their peoples used the earth itself, tamping certain mixtures into walls or forming them into bricks to be dried in the sun. Later they baked these substances in kilns, producing a range of bricks and tiles with greater durability.
Thus, early cultures used substances occurring in their environment and invented the tools, skills, and technologies to exploit a variety of materials, creating a legacy that continues to inform more industrialized methods.
Building with stones or bricks is called masonry. The elements cohere through sheer gravity or the use of mortar, first composed of lime and sand. The Romans found a natural cement that, combined with inert substances, produced concrete. They usually faced this with materials that would give a better finish. In the early 19th century a truly waterproof cement was developed, the key ingredient of modern concrete.
In the 19th century also, steel suddenly became abundant; rolling mills turned out shapes that could make structural frames stronger than the traditional wooden frames. Moreover, steel rods could be positioned in wet concrete so as to greatly improve the versatility of that material, giving impetus early in the 20th century to new forms facilitated by reinforced concrete construction. The subsequent profusion of aluminum and its anodized coatings provided cladding (surfacing) material that was lightweight and virtually maintenance free. Glass was known in prehistory and is celebrated for its contributions to Gothic architecture. Its quality and availability have been enormously enhanced by industrial processing, which has revolutionized the exploitation of natural light and transparency.
Construction
When masonry materials are stacked vertically, they are very stable; every part is undergoing compression. The real problem of construction, however, is spanning. Ways must be found to connect walls so as to provide a roof. The two basic approaches to spanning are post-and-lintel construction and arch, vault, and dome construction. In post-and-lintel construction, lintels, or beams, are laid horizontally across the tops of posts, or columns; additional horizontals span from beam to beam, forming decks that can become roofs or be occupied as floors. In arch, vault, and dome construction, the spanning element is curved rather than straight. In the flat plane of a wall, arches may be used in rows, supported by piers or columns to form an arcade; for roofs or ceilings, a sequence of arches, one behind the other, may be used to form a half-cylinder (or barrel) vault; to span large centralized spaces, an arch may be rotated from its peak to form a hemispherical dome (see Arch and Vault; Dome).
Post-and-lintel solutions can be executed in various materials, but gravity subjects the horizontal members to bending stress, in which parts of the member are in compression while others are in tension. Wood, steel, and reinforced concrete are efficient as beams, whereas masonry, because it lacks tensile components, requires much greater bulk and weight. Vaulting permits spanning without subjecting material to tension; thus, it can cover large areas with masonry or concrete. Its outward thrust, however, must be counteracted by abutment, or buttressing.
Trussing is an important structural device used to achieve spans with less weighty construction. Obviously, a frame composed of three end-connected members cannot change its shape, even if its joints could act as hinges. Fortunately, however, the principle of triangulation-attaching a horizontal tie beam to the bottom ends of two peaked rafters-can be extended indefinitely. Spanning systems of almost any shape can be subdivided into triangles, the sides of which can be made of any appropriate material-wood, rolled steel, or tubing-and assembled using suitable end connections. Each separate part is then subject only to either compressive or tensile stress. In the 18th century, mathematicians learned to apply their science to the behavior of structures, thus making it possible to determine the amounts of these stresses. This led to the development of space frames, which are simply trusses or other elements arrayed three-dimensionally.
Advances in the art of analyzing structural behavior resulted from the demand in the 19th century for great civil engineering structures: dams, bridges, and tunnels. It is now possible to enclose space with suspension structures-the obverse of vaulting, in that materials are in tension-or pneumatic structures, the skins of which are held in place by air pressure. Sophisticated analysis is particularly necessary in very tall structures, because wind loads and stresses that could be induced by earthquakes then become more important than gravity.
Architecture must also take into account the internal functional equipment of modern buildings. In recent decades, elaborate systems for vertical transportation, the control of temperature and humidity, forced ventilation, artificial lighting, sanitation, control of fire, and the distribution of electricity and other services have been developed. This has added to the cost of construction and has increased expectations of comfort and convenience.
In modern architectural terminology the word program denotes the purposes for which buildings are constructed. Certain broad purposes have always been discernible. The noblest works-temples, churches, mosques-celebrate the mysteries of religion and provide assembly places where gods can be propitiated or where the multitudes can be instructed in interpretations of belief and can participate in symbolic rituals. Another important purpose has been to provide physical security: Many of the world's most permanent structures were built with defense in mind.
Related to defense is the desire to create buildings that serve as status symbols. Kings and emperors insisted on palaces proclaiming power and wealth. People of privilege have always been the best clients of designers, artists, and artisans, and in their projects the best work of a given period is often represented. Today large corporations, governments, and universities play the role of patron in a less personal way.
A proliferation of building types reflects the complexity of modern life. More people live in mass housing and go to work in large office buildings; they spend their incomes in large shopping centers, send their children to many different kinds of schools, and when sick go to specialized hospitals and clinics. They linger in airports on the way to distant hotels and resorts. Each class of facility has accumulated experiences that contribute to the expertise needed by its designers.
The attention of clients, architects, and users is more and more focused on the overall qualities manifested by aggregates of buildings and parts of cities as being more significant than individual structures. As the total building stock grows, conserving buildings and adapting them for changes in use becomes more important. See City Planning.
Aesthetics
The aesthetic response to architecture is complex. It involves all the issues already discussed, as well as other, more abstract qualities. An experience of architectural space is personal and psychological; it differs from that of sculpture or painting because the observer is in it. It is affected by associations the observer may have with the materials used and the way they have been assembled, and by the lighting conditions.
Structural logic may or may not have been dramatized. Elements such as windows, and their scale and rhythm, affect the observer, as do the interplay of geometrical form and the way space is articulated. Movement through a sequence of spaces has narrative force; no single point of view is adequately descriptive. The recurrence of thematic forms, appearing in varied guises and contexts, contributes to unity and creates feelings-relaxation and protection or stimulation and awe. Perhaps the key element is proportion-the relation of various dimensions to one another and their relation to human scale.
During the mid-19th century, architecture became institutionalized as a profession requiring formal preparation and subject to codes of performance. During this period connoisseurship-full academic training in the history of architecture and its aesthetics-was the designer's most important qualification. In every Western country the ?cole des Beaux-Arts in Paris was accepted as the model for architectural education. Architecture was easily separated from engineering, which had pragmatic rather than aesthetic goals. Yet today the profession delivers not only aesthetic guidance but also a bewildering array of technical services requiring many specialized contributors. The architect strives to maintain the position of generalist, one who can take the long view while orchestrating the resolution of complex interrelated issues.
The Ancient World
For the convenience of Western readers, the architecture of the ancient world, of the Orient, and of the pre-Columbian Americas may be divided into two groups: indigenous architecture, or ways of building that appear to have developed independently in isolated, local cultural conditions; and classical architecture, the systems and building methods of Greece and Rome, which directly determined the course of Western architecture.
Indigenous Architecture
The oldest designed environments stable enough to have left traces date from the first development of cities.
Mesopotamia
This region, the greater part of modern Iraq, comprises the lower valleys of the Tigris and Euphrates rivers. The Assyrian city of Khorsabad, built of clay and brick in the reign of Sargon II (reigned 722-705 BC), was excavated as early as 1842, and much of its general plan is known. It became the basis for the study of Mesopotamian architecture, because the far older cities of Babylon and Ur were not discovered and excavated until the late 19th and 20th centuries. See Mesopotamian Art and Architecture.
Early Persian architecture-influenced by the Greeks, with whom the Persians were at war in the 5th century BC-left the great royal compound of Persepolis (518-460 BC), created by Darius the Great, and several nearby rock-cut tombs, all north of Sh?raz in Iran. See Iranian Art and Architecture.
Egypt
The urban culture of Egypt also developed very early. Its political history was more stable, however, with strong continuity in the development and conservation of tradition. Also, granite, sandstone, and limestone were available in abundance. These circumstances, in a cultural system conferring enormous power on rulers and priests, made possible the erection, over a long period, of the most awesome of the world's ancient monuments.
Each Egyptian ruler was obsessed with constructing a tomb for himself more impressive and longer lasting than that of his predecessors. Before the 4th Dynasty (begins c. 2680 BC) Egyptian royal burial took the form of the mastaba, an archetypal rectangular mass of masonry. This evolved into the stepped pyramid and finally into the fully refined pyramid, of which the largest and best preserved are those of Khufu (built c. 2570 BC) and Khafre (circa 2530 BC) at Giza near Cairo. These immense monuments testify to the pharaohs' vast social control and also to the fascination of their architects with abstract, perfect geometrical forms, a concern that reappears frequently throughout history.
Egyptians built temples to dignify the ritual observances of those in power and to exclude others. Thus, they were built within walled enclosures, their great columned halls (hypostyles) turning inward, visible from a distance only as a sheer mass of masonry. A hierarchical linear sequence of spaces led to successively more privileged precincts. In this way was born the concept of the axis, which in the Egyptian temples was greatly extended by avenues of sphinxes in order to intensify the climactic experience of the approaching participants. The temples also introduce the monumental use of post-and-lintel construction in stone, in which massive columns are closely spaced and bear deep lintels.
The best-known Egyptian temples are in the mid-Nile area in the vicinity of the old capital, Thebes. Here are found the great temples of Luxor, Karnak, and Deir al Bahri (15th-12th century BC) and Idfu (3rd century BC). See Egyptian Art and Architecture; Temple.
India and Southeast Asia
Hindu traditions are rich in visual symbols; the early stone architecture of India was elaborately carved, more like sculpture than building, especially as the designers did not emphasize structural systems and rarely faced the task of enclosing large spaces.
India
The Indian commemorative monument takes the form of large hemispherical mounds called stupas, like the one built from the 3rd century BC to the 1st century AD, during Buddhist ascendancy, at Sanchi, near Bhopal in central India.
In the early period of monastery and temple building, shrines were sculpted out of the solid rock of cliffs. At sites such as Ellora and Ajanta, northeast of Bombay, are great series of these artificial caves carved over many centuries. As the art of temple building developed, construction by subtraction gave way to the more conventional method of adding stones to form a structure, always, however, with more concern for sculptural mass than for enclosed volume.
Hindu temples are found throughout India, especially in the south and east, which were less dominated by the Mughal rulers. Jainism, still a very successful cult, has its own temple tradition and continues to build on it. See Indian Art and Architecture.
Southeast Asia
In Southeast Asia a ...