Traditionally, most of the construction process took place at the building site (though some elements were formed elsewhere, e.g. the hardwood members of timber-framed buildings were shaped and jointed in yards and taken to the site for erection). However, the first half of the twentieth century saw industrialised processes introduced into the UK construction industry. At their simplest, these involved the use of factory-produced components within the traditional building process, e.g. roof trusses. More wide-ranging methods of non-traditional or system building were also introduced. These ranged from the use of in-situ factory techniques, such as shuttered and poured concrete walling, to the site assembly of pre-fabricated components, e.g. timber, steel or concrete frames, and cladding. It is worth noting that most system building involves elements of both traditional and industrialised construction methods. In particular, the substructure is usually formed in situ rather than assembled from delivered components. There were a number of apparent beneficial factors that led to the introduction of system building: • Efficiency. Factory processes would make the best use of available labour and materials to

produce as much of a building as possible.