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Materials and technical ability When a building is constructed two main physical resources are involved. These are materials necessary to form the various parts, and technical ability to assemble the parts into an enclosure. Initially, the materials employed were those which could most easily be obtained from the accessible areas of the surface of the earth. The technical ability was mostly simple, having evolved from the convenient methods of economically working the rudimentary characteristics of these available materials. The gradual widening in means of communication and corresponding developments in attitudes led to an increased range of these resources becoming available. The current uses of particular construction methods no longer need to rely on locally available materials or traditional technical ability. Continued investigation has resulted in the enormous range of materials now becoming available which may be used singly, in combination with one another, or even to form new materials. Technological developments are interrelated with this range and use of materials, and enable virtually anything to be constructed. Nevertheless, there are certain considerations which have always exerted some control on the indiscriminate use of resources. These controls remain, and now that the range of resources is wider, and attitudes towards the function of a building are more complicated, the selection of appropriate construction method becomes much more difficult. Hence, it’s first necessary to understand precisely what is required of a building before selecting an appropriate method of construction. ---1 Construction method. Functional requirements Elaborate shelters have been, and still are, made by most species of insects, reptiles and animals capable of using the readily available materials (earth, stones, branches and leaves, etc.) with the aid of the inherent manipulative skills (technology) of their arms, legs, wings, claws, beaks and jaws. Early humans also required shelter which provided security for them, their possessions and activities. However, they developed their inherent manipulative skills by inventing tools which led to less indigenous construction methods and also ways of changing the natural state of materials so that they could be used to greater advantage. Each innovation devised usually resulted in shelters, which, although initially providing a good standard of comfort and convenience, eventually became sub standard accommodation as requirements became more elaborate. But, regardless of technical developments, the provision of a physically comfortable shelter was not the only or even the principal reason for building. From early times, a building was also required to give an established place of social and religious identity: it must indicate culture, status and mood, whilst creating the humanized space in which to learn, experience and carry out normal daily functions in comfort. Sir Henry Wooten, a 15th-century humanist who adapted the writings of Vitruvius for his book, The Elements of Architecture (1624), wrote that a good building must satisfy three conditions:
These functional requirements are implicit in the provision of a shelter which is also a building fit for human habitation. A well-constructed building reflects contemporary attitudes towards environmental control, structural concepts and aesthetic excellence. and the materials and technical ability used throughout history have normally provided the means of achieving these particular ends. Performance requirements A modern building is expected to be a life-support machine. It’s required to provide the facilities necessary for human metabolism such as clean air and water, the removal of waste produce, optimum thermal and humidity control, privacy, security and visual/acoustic comfort. It’s generally required to be a source of (perhaps self generating) energy for appliances, and provide means for communication with television, telephones and postal services. In addition, a building must be safe from collapse, fire, storm and vermin; resistant to the physical forces of snow, rain, wind and earthquakes, etc.; and capable of adaptation to various functions, external landscaping or internal furniture arrangements. It must also be easily, economically, quickly and well constructed; and allow easy maintenance, alterations and extension as well as having a sustainable form of construction which can be adapted to changing trends and legislative requirements. All this must be accomplished in the context of providing a building which has character and aesthetic appeal. Criteria of this nature form today's interpretation of the basic functional requirements for a building quoted earlier. In order for them to be conveniently considered, it’s necessary to divide a building into the various related duties to be fulfilled and establish the precise performance requirements for each. When these duties are incorporated into a building where the functional requirements have been clearly defined, the selection of a suitable construction method (materials and technology) can be achieved by using the criteria given by the performance requirements under the following headings:
Performance requirements cannot be placed in order of importance because any one of them may be more critical than another for a particular element of a building. Priority is normally dictated by the precise function and location of a specific building. The use of these interrelated performance requirements in establishing a building design was instigated many years ago by the then US Building Research Station (now US Building Research Establishment). Although firm principles have now been established, critical factors arise which result in fundamental changes in attitudes towards construction methods. In recent years, one such influence concerns the availability of energy resources for the production of building materials, and for the heating and lighting of buildings. ---.2 Performance requirements for a building. ---.3 Energy consumed by the building industry. [[ Mineral content of oceans and the earth's crust related to present consumption (million tons) Metal | Known reserves | Current annual consumption | Total natural occurrence in oceans, including the seabed | Total natural occurrence in the first mile of the earth's crust (under dry land)
During the formation of the earth some 5 billion years ago, only a relatively small amount of hydrocarbon atoms were incorporated and these now form our fossil fuels of gas, oil and coal. These fuels have been continuously used in one form or another during the development of humankind and the rate of consumption has increased rapidly over the last 40 years. As a result of this situation, even if the world population were stabilized, the requirements for fuel were static, and the poorer countries remained undeveloped, there would be only another 40 years of gas supply, 25-30 years of oil, and 200-300 years of coal requirements for the whole building. Research and development is continually taking place in these areas, and it’s the duty of those involved in the design and erection of buildings to be aware of current trends. The achievement of this knowledge cannot be solely through any published building law or contemporary code of good practice, as by the time they have been established other discoveries and experiences may already have taken place. Previous: Building Construction for Dummies: Article Index |