In the past architects were trained to be aware of the
types and uses of traditional materials and their means
of assembly. It was not unusual for an architect to
select the type of brick to be used knowing the
source of its clay and the appropriate type of mortar,
its thickness and how the bricks would be laid. The
actual construction of the wall would be dependent
on the craftsmanship of the bricklayer but there would
be a common understanding between the workman,
and the specifier of the standard of construction and
the appropriate means of detailing. Each would be
effectively checking the other. As building construction
has become more complicated and the choice of
materials increased, this sense of understanding
between the builder and the architect can no longer
be relied upon. In many cases the architect is not
totally aware of the sources of the subcomponent
parts which make up an assembly; for example, only
relatively few architects would know the difference
between polyurethane and polystyrene insulation in a
composite metal panel, but this is fundamental to the
fire performance of that panel. Partly this is because
of education, partly lack of interest and partly because
of the complexity of designing and organizing a
modern building project. In this situation the architect
is more dependent on specialists for advice on the
parts of a building such as cladding.