BeamArchi

Although the arch is a common feature of the architectures of many cultures, there have been others which seldom or never used it. The "ancient Greeks" seem to have ignored the arch, although some of them had mathematical knowledge which might have helped in design and construction. The picture shows a building which borrows Greek ideas.

The beam is attractively simple, deceptively simple, and very limiting. By rejecting the arch in favour of a beam, we relinquish the ability to use the horizontal strength of the ground, resulting in forces in the structure that are far greater than the actual loads. And the forces within a beam are not easy to calculate.

So when we look at a structure using stone beams, we will always see short spans, heavy lintels, and probably a great number of uprights. Building a vast empty roofed space using stone beams is out of the question.

Look at Stonehenge, an ancient Egyptian temple, or an ancient Greek temple. There must have been few "seats with a good view" in some of these many-pillared structures. Perhaps the concepts of worship were such that viewing by a congregation was not an important consideration. On the other hand, the practice might have been a result of the architecture.

A place where you definitely need to see well is a theatre. Greek theatres, in fact, were outdoor constructions, with no attempt at a roof, often built into a hillside, unlike the constructed Roman amphitheatres.

With an arch you can build centring and use it as ramps to carry up the voussoirs one by one. With a beam it is all or nothing; a straight lift, unless you build ramps which do nothing for the structure itself. The beam is one massive object: you cannot break it down into convenient blocks. The arch wins every time.

Here is a view from high on St Peter’s, Rome. The colonnade is rather like a gigantic version of Stonehenge, artistically far more sophisticated, but in engineering terms, not so very different. Some people refer to architecture based on pillars and beams as trabeated architecture, as opposed to that based on arches.

More columns and beams in Rome. If you wish to impress or intimidate, a massive building with many rectangles, beams and columns is a good form of architecture to use.

Classical forms can also be imposing, or decorative and attractive, if used on a smaller scale, but when you see a classical portico with fluted columns on the front of a small town house you might wonder if this is too far in the other direction.

At the same time that modern materials and computational methods have released architects from many old constraints, the ease of construction of reinforced concrete beams, pre-stressed concrete beams, and rolled steel joists, (RSJs), has led to the building of a vast number of rectangular buildings. Often these have lacked the multiplicity of details at different scales which allow the eye to take pleasure in viewing a building. But in the right hands, extreme simplicity can work very well.

This is, of course, a matter of opinion. You may prefer the relatively plain outside of the duomo in Siena, or you may prefer the ornate inside, packed with artefacts. You can even admire both, or neither. It seems that many people prefer fewer ornaments than in older times. Many medieval churches had numerous paintings on the walls, of which very few traces remain. Not many people would now approve of a proposal to cover these buildings with paintings again.

The influence of de Stihl, le Corbusier (Jeanneret), and other artists, architects and theoreticians may have lent authority to the modern movement. There is nothing wrong with rectangles, but any construction requires sensitive design if it is not to lead to boring or ugly buildings. Disciples do not always possess the artistry of the masters. Some people say that we are what we eat. You might just as well say that we are what we see, or even what we don’t see, because everyone sees different things when looking at the same scene. The work of architects and builders may well have strong effects on the way people feel, though not necessarily in the intended ways.

Tourists know what they want to see, and it seldom includes modern buildings, even ones that are considered to be masterpieces.

Here are some town views showing modern buildings, often close to older ones.

In a country where sunlight is not strong, and many days are dull, a large area of grey untextured concrete is a good recipe for drab surroundings. The response of materials to wear and tear and to weathering is very important in the design of buildings. Some materials and coatings can look very tatty quite quickly. The effects of water running down and depositing impurities can, over a long period, detract from appearance. Metal, concrete and plastic surfaces are among the materials which can degrade unattractively. See the page about appearance for more discussion.

How much of this is subjective? Tourists are often quite happy to see very old buildings, heavily weathered, not very clean, with bits missing, and showing clear deviations from horizontal and vertical, some original – others the result of time. Will people one day call steel and concrete buildings quaint? Will the buildings last that long?

This building includes both trabeate and arched designs. The frontage deviates very slightly from straight. What could be the reason for this? The yellowish "pillars" carry no load at all: they are merely affixed to the front of the building. A frontal view reveals that they are quite strongly bulged, as if to suggest the great load they are supposedly carrying. As the real load-bearing pillars behind (which may themselves conceal steel girders) are perfectly straight, the result is incongruous. Perhaps they are intended as a joke.

Some people like "functional" things. One function of functional things is to please people who like functional things. There’s nothing wrong with functionalism – who wants a teapot that looks elegant, but dribbles? These caryatids are functionalist – they don’t need arms – and they don’t have arms. That must have saved a bob or two.

Look at the pictures below. Are the profiles of the pillars straight, or slightly curved? Does it make a difference? What about the ratio of width to height? The appearance of a structure can be affected by quite small details, or even by their absence. People often modernize their houses by replacing doors and windows. If the changes are too great, the balance of the design can be changed.

Here are some buildings which have various proportions of rectangular and arched windows. In earlier times, these were fashionable dwellings in a spa town: now they are either offices or apartments.

This picture, of a part of the same town, shows a mixture of buildings of different ages. In the foreground is a late 20th century office block, far taller than any other building in the town. Behind it is a block of apartments built at the start of the 21st century. At the top left is a school in a mock gothic style, including, at the extreme top left, a huge sports pavilion. Many other buildings in the picture are elegant houses.

What do you do if you have to build something new in an area with an established character? Clifton, near Bristol, has numerous elegant streets, like the examples already given. The builders of the Roman Catholic cathedral chose to construct a building in a modern idiom, as did those in Liverpool. The Church of England cathedral in Liverpool is a complete contrast – a massive structure in Gothic style.

Where large delivery vehicles need to pass, the beam is the logical solution for an entrance. The second example isn’t really rescued by the bunting: it still looks dull.

Just because they look like arches, it doesn’t mean that they are. These are not connected to the buildings on either side, so they must be beams. Waterloo Bridge in London has curved spans, but they are haunched beams, not arches, giving good headroom while transmitting the forces through the bridge.

Administrative building and lecture theatre at CERN, Meyrin. A few departures from a strict rectangular construction make the building more interesting. White concrete, and strong sunlight, add the final touches.

Cartmel College, Lancaster University. The buildings on this campus are variously faced with brick and concrete, often white or textured, avoiding monotony. Compare Essex University.

At Les Avanchets, Geneva, colour and form have been used to avoid the effect of vast areas of grey concrete in an area with numerous large apartment buildings.

Buildings at Meyrin, north west of Geneva, are smaller than those at Les Avanchets. Meyrin is a pleasant cité satellite, with a good shopping centre, good schools, and cultural facilities. Balconies allow people to install sun-shades, flowering plants, and other things that add colour and variety. Alongside these buildings are those of the older village.

Ever since the invention of iron framed and steel framed buildings, there has been no need for the outer surfaces of a building to be load bearing. In fact they need not be vertical, or even flat.

This second example shows the outside of Explore At Bristol, an exploratory containing many exhibits, largely interactive, about engineering and science. Children of all ages may enjoy it.

Here is a picture showing Birmingham airport. If you are bored at an airport you can wander around and look at the architecture and structures. At JFK you can even look at the famous TWA terminal by Saarinen, Ammann and Whitney. At the right of this photograph are some of the huge boxes which comprise the National Exhibition Centre – trabeated "architecture" taken to its limit of simplicity. The roofs of such buildings are often supported by light trusses or space frames. At the far right you can see the red tension bars holding up the roof of the National Indoor Arena.

Not all beams are horizontal. These are glass houses in Kew Gardens. At their lower ends there must be provision to contain the thrust they generate. Beams like this could butt against thrust blocks with strong foundations, or they could be tied by rods under the ground. These beams are in compression, unlike horizontal ones. You could even think of these structures as primitive arches.

Here is an attempt to escape from the right angle.

Other deviations from the right angle have included octagonal church towers, such as that at Hornby in Lancashire, which is unusual in that the upper section of the tower is rotated by 22.5° with respect to the lower part. Many medieval castles had circular towers, probably for defensive reasons.

A modern building.

Schools

To see how styles and techniques change with time, it can be useful to look at a series of buildings intended for a single purpose. Here are some English schools in styles of different periods, in order of construction –

Some of these pictures illustrate the dominance of the rectangle in the middle decades of the 20th century. Some of the pictures at the top of the page about arches in architecture show that in the last two decades of the 20th century there was a return to the use of circles and arches, and more imaginative design in general, exemplified by the last picture in the set above. During the rectangular period, many school buildings took the form of prefabricated boxes, similar to those used for temporary buildings in building sites and industrial areas.

Japanese Buildings

Older Japanese styles, based on styles imported from China, used wood, making extensive use of beams, and large eaves based on cantilevered brackets. The rectangles were relieved by the slight curvature of the roof lines. Rooms, too, were based on endless, yet never boring, permutations of rectangles, built around the standard tatami, the rectangular mat with proportions of 2 : 1. These pictures show the Todaiji Temple, in Nara, the Heian Shrine in Kyoto, the Golden Pavilion in the Kinkakuji Temple in Kyoto, and a temple in Kamakura. The Tojaidi is the largest wooden building in the world.

The ubiquitous rectangle is occasionally relieved by something quite different, as in the case of this wall, which is built from massive and immovable looking blocks.

Here is a modern equivalent in England, with a water garden and huge eaves on the building. This is a part of a business park.

Other buildings in the same park are little more than steel I-beam frames with glass and metal skins. Many people in this type of building do not see any natural light, let alone a view outside.

A Puzzle

An old mathematical problem concerns the maximum amount by which a pile of bricks can overhang before falling over. It turns out that the critical overlap of the Nth brick from the top is 1/Nth of the length of a brick. The proof neglects the imperfect rigidity of the bricks and the foundation. The shape is reminiscent of some species of snake when threatening to strike.

Although this is an impractical object, a set of diving boards at Coate Water, south of Swindon, is supported by a concrete tower which has a shape which looks a little like a smoothed version of this pile, although it has a subsidiary support at the back.

This pile of bricks violates the rule of the middle third, which states that the centre of gravity should lie over the middle third in both dimensions, that is, it must lie in the middle ninth of the area. Only then can we be sure that tension will not develop anywhere. In masonry, the rule should be followed from top to bottom. If there are transverse forces, as in a buttress or a retaining wall, it is the funicular which must lie within the middle third.

Under this rule, the overhang must be reduced, or the length of the blocks must be increased. What is the new formula for piling up the bricks? Is the trick even possible?

Not a Building

This is not a bridge or a dam, and it is not a building. What is it? It is one of the exhibits in the Yorkshire Sculpture Park. So what are we to look for? We could wonder about the soil and the foundations, since it shows no sign of relative movement. We might also wonder whether it is hollow: the objects that are apparently blocks might even be thin slabs fixed to a frame. We could even ask whether the work is aligned with a standard compass bearing.

This sculpture, not far from the previous example, illustrates the tendency of art to produce asymmetry: the first example was atypical in this respect. But asymmetry does not mean lack of form – the positions and shapes of the forms were chosen by the artist to produce whatever effect he desired.

And here is yet another type of construction in the same park.

Half Timbered Buildings

The half timbered building has a wooden frame, filled in with brick or some other material. This construction has the advantage that should any movement occur, the effects are localised within the frames, and cracks cannot spread. The effect of subsidence is far less serious than it would be in a building made entirely of bricks. One of the examples shown below has sunk very visibly. Another benefit of the infill is that it tends to rigidise the frames, though in fact many buildings include a few triangles.