arris The sharp edge formed where two surfaces meet.
balloon framing A timber-construction technique, in which long timber studs are assembled for the vertical elements first and the floors subsequently attached to these. Most commonly found in North America and Scandinavia.
caryatid A full (usually) female figure in place of a supporting column to hold up the entablature of a building. Male caryatids were also used – called atlantes – as well as three-quarter-length figures – herms – and other creatures, both mythical and actual.
catenary arch An arch like an upside-down catenary, the shape made when a chain or rope is allowed to hang under its own weight. The Gateway Arch in St Louis, Missouri, is a classic example.
coffering Ceiling decoration that is made up of sunken panels, either square or polygonal.
compound dome A dome in which the pendentives beneath the dome proper form part of a larger sphere on which the dome sits. This is to be distinguished from a simple dome, where the pendentives are part of the same overall sphere as the actual dome.
ethylene tetrafluoroethylene ETFE is a polymer with a high resistance to the effects of weathering and other destructive forces. In architecture, it has been used as an outer skin for such high-profile projects as the Eden Project, Cornwall, and the Beijing National Aquatics Center, China.
fan vault A vault where the decoration consists of fan-shaped cones of ribs that do not quite meet at the apex of the vault, so leaving a flat lozenge-shaped area. Most often found in English Gothic cathedrals.
geodesic dome This is a dome constructed from the triangular sections that are created when circles are drawn onto a sphere. They are very strong but lightweight structures that can be used to cover large areas.
inflexed arch In its simplest form, an arch in which the radii are inverted, or inflexed, such that they form a structure with a pointed apex curving down and out to the springer. These can sometimes have multiple points within the arch, but always with the curves facing into rather than out of the negative space.
parabolic arch An arch similar to a catenary arch formed out of a parabola. This is a very strong form that needs no extra support to take the forces exerted. First used in the late 19th century by the Spanish architect Antoni Gaudí.
piloti Columns or pillars that raise a building above ground level so leaving the street level open.
platform framing A form of timber construction in which – once the understructure is assembled – the upright elements are built on top of the platforms that make up the floors of each storey. Much used in North America as a less labour-intensive form of construction than the more traditional balloon framing.
saucer dome A dome where the section is shallower than a semicircle. One modern example of this is the Louisiana Superdome in New Orleans.
‘skin-and-bone’ architecture A term used by Modernist architect Mies van der Rohe to describe his style of architecture, in which the ‘skin’ of the walls is laid onto the ‘bone’ of the frame of the building.
springer The section of an arch at the top of the uprights and from which the arch itself ‘springs’.
tied arch Most often used for bridges, this is where the arched element of a structure is ‘tied’ to the horizontal over which it spans to counteract the outward forces exerted on the arch.
voussoir A wedge-shaped stone or other tapered element of an arch.
wagon vault Alternative name for a tunnel vault, the most basic vault with no cross vaulting.
Ancient Greek stone architecture used a system of vertical columns and horizontal architraves. This type of structure originated in simple wooden constructions and did not allow for wide spans, which limited the scope of architectural possibilities. However, once the ancient Etruscans developed the first arches, the erection of much larger masonry structures such as bridges and aqueducts became possible. The arch was adopted by the Romans, who also built triumphal arches as monumental passageways to celebrate military victories. Arches have come in many forms and shapes over the centuries, including the Roman semicircular arch, the Gothic pointed arch and trefoil arch, the Moorish horseshoe multilobed arch and the Baroque elliptical arch. There are also flat, tied and inflexed arches, but the strongest are parabolic and catenary arches, introduced by Spanish architect Antoni Gaudí in the 19th century. Both parabolic and catenary arches are designed to carry all the downward forces into the ground without using buttresses or other supports. The arch continues to be a common architectural feature, and is still often used today for wide-span steel bridges.
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An arch is a curved load-bearing structure that spans a void. Vertical forces are carried through the arch and into supporting abutments, called piers.
3-MINUTE ELEVATION
In a conventional arch, all the individual elements are arranged to create a closed system. The first stones above the supporting piers are the springers, which carry the wedge-shaped elements called voussoirs. The keystone at the apex of the arch completes the structure. However, depending on the curve, horizontal forces can push outwards at the base. In Gothic cathedrals, for example, external elements – flying buttresses – counteract these forces, channelling them into the ground.
RELATED TOPICS
3-SECOND BIOGRAPHIES
EERO SAARINEN
1910–61
Finnish-American architect, who erected the catenary Gateway Arch in St Louis, Missouri
SANTIAGO CALATRAVA
1951–
Spanish architect/engineer who designs slim-dimensioned steel arched structures
30-SECOND TEXT
Marjan Colletti
Arches are very distinct features and, as such, an aid to recognizing the style of architecture.
Simple domed structures of perishable materials such as wigwams and igloos date back to prehistoric times, but the dome proper was developed during the Roman Empire – and at 43 m (142 ft), Rome’s Pantheon (c. 126) is still the world’s largest hemispherical, coffered, non-reinforced-concrete dome. Domes come in a multitude of different types and shapes: corbel domes (in the ancient Middle East), onion domes (in Russia, Turkey, the Middle East, and India), compound ones supported by pendentives such as the Hagia Sophia in Istanbul (537), spherical or part-spherical geodesic domes, flat-saucer domes, or polygonal domes – for example, the structurally ingenious double-shelled octagonal dome for the Renaissance Duomo in Florence by Filippo Brunelleschi, completed in 1436 and erected without scaffolding. Later, light and transparent cast-iron-and-glass domes for botanical gardens (for example, Kibble’s Palace, Glasgow, of the 1860s) and arcades such as Giuseppe Mengoni’s Galleria Vittorio Emanuele II, Milan 1877), were built. The 20th century saw the development of thin prestressed-reinforced-concrete shells and modular geodesic domes made of a web of thin steel struts filled with glass, plastic, fabrics, or ethylene tetrafluoroethylene (ETFE) pillows (for example, the Eden Project, Cornwall, designed by Sir Nicholas Grimshaw).
3-SECOND FOUNDATION
A dome is a vaulted structure with a rotund shape and with a circular, polygonal, or elliptical base that allows for large clear-span structures.
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A dome can be described as an arch revolved around its central axis. They are thus very stable and sound structures, since vertical arches and horizontal ring beams act together. Openings in domes are possible, as exemplified by the oculus, a round window at the apex of the dome. It is often crowned by a lantern, which gives additional stability to the structure through its own weight.
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3-SECOND BIOGRAPHIES
PIER LUIGI NERVI
1891–1979
Italian engineer, known for his large-span, prestressed reinforced-concrete structures
PAUL ANDREU
1938–
French architect, designer of the titanium-and-glass ellipsoid dome-shaped National Center for the Performing Arts, Beijing
30-SECOND TEXT
Marjan Colletti
Domes are a prominent feature in mosques and most Renaissance and Baroque cathedrals.
Simple vaults were used by the Sumerians, Assyrians, Chaldeans and Egyptians. Later, Etruscans and Romans managed to erect vaulted amphitheatres, basilicas and thermae without buttresses. The largest ancient vaults roofed the iwan hall of the Taq-i Kisra in Ctesiphon, Iraq (43 m/141 ft), and in Rome the Temple of Venus and Roma (27 m/87 ft), Basilica of Maxentius (25 m/82 ft) and the throne hall in Diocletian’s palace (30 m/98 ft). Medieval stonemasons developed extremely complex and varied forms of intersecting vaults. With the Gothic pointed arch, vaults could be divided into four, six or more segments, with many arrises and ribs of unequal width, yet intersecting at the same height. Particular to England are fan vaults, most famously in King’s College Chapel, Cambridge (1536). Renaissance and Baroque architecture abandoned the Gothic rib vault to reinvent and further develop Roman vault types. Until the 20th century vaults were always constructed in separate elements and enriched with glass, frescoes, carvings and sculptures. In the 20th century, reinforced-concrete technology, lightweight shell construction, advanced structural engineering and a better understanding of geometric shapes such as paraboloids facilitated the erection of impressive slim-dimensioned shells, vaults and domes.
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A vault is an arched spatial structure that spans a void. Weight is carried through the vault in compression and into supporting piers or buttresses.
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The most conventional form is the semicircular or pointed barrel (or wagon, or tunnel) vault. Two intersecting barrels of the same diameter create a groin (or cross) vault; the resulting ridges are called arrises. We speak of rib vaults when barrel vaults with matching or different diameters transect, with the groins subjected to extra masonry work. A particularly elaborate type is the fan vault, with equidistantly arrayed ribs of the same curve.
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3-SECOND BIOGRAPHIES
JOSEPH PAXTON
1803–65
English architect, designer of the Crystal Palace, London
LOUIS I. KAHN
1901–74
American architect, designer of the vaulted Kimbell Art Museum, Fort Worth, Texas
FÉLIX CANDELA OUTERIÑO
1910–97
Spanish architect, famous for extremely thin reinforced-concrete shells
30-SECOND TEXT
Marjan Colletti
Depending on height, geometry and curvature, vaults can be load-bearing structures or light canopies.
The beam is one of the oldest, most basic structural elements known to humans. Even before nomadic pastoralists started settling on the land and building permanent structures, the beam was used by people to construct temporary dwellings or to cross streams by means of a felled tree. Whether a small stick covering a makeshift shelter or a massive precast reinforced-concrete girder supporting the roof of a modern building, both are beams performing the same function of withstanding vertical loads across a void. These vertical forces are shared between the supports at either end of the beam and transferred through the structure. In architectural terms, these supports are usually the walls of the building or the columns in a timber, steel or concrete frame. The beam also masquerades as other elements, such as joists, which span opposing walls to support the floors or ceilings of a building, or lintels that support the structure above windows or doors, or girders designed to span wide distances or carry particularly heavy loads. Traditionally, stone, wood and metal were the most common materials used for beams, but in recent decades combinations of materials – notably reinforced, pretensioned, or post-tensioned concrete – have greatly improved performance.
3-SECOND FOUNDATION
There are many different types of beam, but in its simplest form a beam is a rigid horizontal load-bearing member supported at its ends.
3-MINUTE ELEVATION
The ability of a beam to withstand vertical forces may be judged intuitively by the span-to-depth ratio. This is defined by the relationship between the depth of a beam’s cross section and the distance between the supports at either end. If the span is narrow and the section is thick, the beam may appear unnecessarily massive and unwieldy, whereas if the span is too wide and the section too thin, the beam may fail.
RELATED TOPICS
30-SECOND TEXT
Edward Denison
One of the most elemental structural components, the beam, in its simplest form, is a horizontal load-bearing member supported at each end.
Palladio – who showed 17th- and 18th-century Europe how to express the harmonies and proportions of Vitruvian Rome – is universally acknowledged as one of the seminal influences on Western architecture. He did not seem to be the most likely candidate for such fame to begin with. Born in 1508, Andrea Pietro della Gondola was a miller’s son from Padua, apprenticed to a stern stonemason at the age of 13. He hated it, and when he was 16 he ran away to Padua where he joined another mason’s yard. His big break came in 1537 when he was employed by humanist scholar Gian Giorgio Trissini to work on his villa at Chiericati. Trissini took to the young Gondola and introduced him to Renaissance culture, including the ideas of Vitruvius, and even gave him the name Palladio, meaning ‘the Wise One’, after a character in one of his own poems, in turn named for the Greek goddess Pallas Athena. Palladio proved more than worthy of his patronage and began to make a name for himself from the 1540s onward. Industrious and gifted, he worked mostly around Venice and Vicenza, concentrating on church architecture, palaces and, above all, villas, of which he produced around 30 that were inspired by the agricultural villas of ancient Rome. It is for the Villa Capra, also known as the ‘La Rotonda’. that he is most famous. A harmonious, graceful, symmetrical edifice, built on Roman principles to a human scale, it influenced, among many others, Sir Christopher Wren, Inigo Jones – who paid homage to it in his Queen’s House at Greenwich, London, of 1616 – and Lord Burlington in England, and, in America, Thomas Jefferson, who based his design for Monticello, Virginia (1772), on it.
Palladio not only built prodigiously, he also published prolifically, producing a guide to the ruins of ancient Rome and contributing illustrations to Barbaro’s edition of Vitruvius’s De Architectura. His best-known work is Quattro Libri dell’Architettura (The Four Books of Architecture), in which he set out his principles of architecture, together with practical guidance for builders and a series of meticulous woodcuts. It became the standard text for architects in Europe, was translated into many European languages and it remains in print today.
Born Andrea Pietro della Gondola in Padua, Italy
1521
Apprenticed to stonemason Bartolomeo Cavazza da Sossano in Padua
1524
Ran away to Vicenza to join the Pedemuro studio of stonemasons
1537
Employed by the writer, diplomat and grammarian Gian Giorgio Trissini
1549
Undertook the reconstruction of the Basilica Palladiano, Vicenza (finished 1614)
1550
Death of Gian Giorgio Trissini; Palladio completed the Palazzo Chiericati, Vicenza
1554
Visited Rome under the patronage of Cardinal Daniele Barbaro, who, among other things, translated Vitruvius into Italian
1554
Started the Villa Barbaro at Maser near Treviso for his patrons Daniele Barbaro and his brother Marcantonio
1556
Started building the Villa Capra (‘La Rotonda’), Vicenza (finished 1585)
1565
Started work on the Church of San Giorgio Maggiore in Venice
1570
Published Quattro Libri dell’Architettura (The Four Books of Architecture)
1577
Began rebuilding the Church of the Most Holy Redeemer (‘Il Redentore’), Venice (finished 1592)
1579
Started work on the Teatro Olimpico in Vicenza, his last work
August 19, 1580
Died, possibly at Maser near Treviso
The column (or pillar) is the fundamental structural unit of architecture. Using the column frees the wall so that, no longer acting as the load-bearing element, it can be treated purely as a covering. A column can be monolithic (of one single block of material, such as stone or wood), sectional (a single material, but sliced and stacked), or it can also be a combination of materials (concrete reinforced with steel). Typically, the column has three parts: capital (immediately supporting the beam, slab or arch); shaft (the main body); and base (connecting the column to the foundation). Early civilizations such as Egypt and Babylonia decorated the column in all manner of shapes and forms. In Classical architecture, the column is codified in decorative orders, and the three parts of the column are treated differently according to which order is used. Classical architecture also uses carved female figures – caryatids – as columns. Columns can be half-set into a wall, forming pilasters. Columns soon became symbolic beyond their structural properties, placed in public spaces to commemorate persons or gods. Pilotis, or piers, are columns that support a whole building above ground; these have become a key feature of modern and contemporary architecture.
3-SECOND FOUNDATION
The column is a load-bearing structural element of architecture. It transmits the vertical forces of a beam, arch, or slab through compression to the foundation.
3-MINUTE ELEVATION
In his Domino House (1915) Le Corbusier argued that by using pilotis and columns instead of walls the architect had complete freedom in designing the plan and elevation. Another Modernist architect, Mies van der Rohe, is celebrated for his use of steel cruciform columns. Postmodern architects have played with the language of stability that the column suggests, cutting them in half or placing them at unusual angles.
RELATED TOPICS
3-SECOND BIOGRAPHIES
VITRUVIUS
fl. 46–30 BC
Roman architect and theorist who recorded the earliest known codification of the orders of columns
LEON BATTISTA ALBERTI
1404–72
Italian architect and polymath who developed the theory that the column could be feminine or masculine in form
30-SECOND TEXT
Nick Beech
The column, as a fundamental structural unit in architecture, has become a symbol for ‘stability’.
The buttress solves a fundamental problem with the wall – at a certain height a wall can topple over under its own weight or from taking the load of a roof or arch. A buttress is any mass of material – such as stone, brick, or concrete – attached to the wall to prevent this. Buttresses are found in city walls and castles across the world – and particularly 11th-century Norman (Romanesque) church and castle architecture in Europe. They can be attached in a series along the face of a wall or at corners formed by the meeting of two walls. The buttress first appears as a continuous or stepped (wider at the base, thinner at the top) column. The flying buttress – detached from the wall and connected to it by an arch – was a key innovation that occurred at the end of the Romanesque and beginning of the Gothic periods. To add greater vertical thrust, the flying buttress is often capped with a heavy load above the arch called a pinnacle, and the history of Gothic architecture is, in part, the history of increasingly spectacular and daring uses of the flying buttress and decoration of the pinnacle.
3-SECOND FOUNDATION
The buttress is a structural element of a wall that resists lateral forces generated by the wall or from load-bearing of a roof or arch.
3-MINUTE ELEVATION
Buttresses are part of the history of the separation of two key qualities of the wall: the wall as a support (holding something up) and as a screen (making a space private). Gothic architecture is completely dependent on the use of the flying buttress as a support to replace a stone screen with a glass screen. In modern architecture, with the use of concrete and steel frames, the buttress is effectively redundant.
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3-SECOND BIOGRAPHIES
EUGÈNE VIOLLET-LE-DUC
1814–79
French architect and theorist, who argued that innovations to the buttress in the 13th century radically transformed architecture
30-SECOND TEXT
Nick Beech
The buttress owes its aesthetic appeal to the fact that it expresses the structural forces of architecture.
Compared with solid masonry constructions, frames are open, more efficient load-bearing structures made of columns, beams, trusses, girders and spandrels. Many traditional construction techniques used wooden frames before the advent of iron and steel. The world’s oldest iron-framed building is Ditherington Flax Mill in Shrewsbury, Shropshire, (Charles Bage, 1797), but high-rise steel frames really took off in Chicago, New York, and London because of the high land values. The world’s first skyscraper was the 10-storey Home Insurance Company Building in Chicago (William Le Baron Jenney, 1885), with a frame of cast-iron columns and wrought-iron beams. In the 20th century, reinforced concrete emerged as the main alternative to frame structures, either poured in situ or assembled from prefabricated elements. A frame does not need to be orthogonal. On the contrary, frames built up by a three-dimensional matrix of triangular and tetrahedral shapes are much more rigid and are often used for massive structures including hangars and bridges. Particularly unusual steel frames feature in the Olympic National Stadium in Beijing (Herzog & de Meuron, Arup and China Architecture Design & Research Group, 2008) and the BMW World Building in Munich (Coop Himmelb(l)au, 2007).
3-SECOND FOUNDATION
A frame is a three-dimensional, lightweight system of connected struts. It provides the structural skeleton to a building and is essential for high-rise buildings.
3-MINUTE ELEVATION
Wood framing is still a common method of construction for apartment buildings in Canada and the United States, including balloon framing and the more recently developed platform framing. The former connects long timber studs and fabricates the walls first, with the floors subsequently attached to them. The latter joins smaller timber sticks to platforms, with the walls built on top of them. Diagonal bracing and panelling add rigidity and stability.
RELATED TOPICS
3-SECOND BIOGRAPHIES
WILLIAM LE BARON JENNEY
1832–1907
American architect, engineer and pioneer of skyscrapers
LUDWIG MIES VAN DER ROHE
1886–1969
German–American architect who achieved free-flowing open spaces thanks to ‘skin–and-bone’ frames
RICHARD ROGERS & RENZO PIANO
1933– & 1937–
British and Italian architects, co-creators of the Pompidou Centre, Paris
30-SECOND TEXT
Marjan Colletti
A building’s elements – concrete, timber or steel – are usually assembled into a 3D frame.
