It is also fairly clear that design codes, applied without thought, are inadequate. A satisfactory compromise is only obtained by the application of a design code in the hands of a competent professional. The design code reflects the best general guide that can be produced from the cumulative experience of the professional group which developed it. The professional consultant must be further concerned with the specific design case and must introduce his own knowledge and judgement in dealing with any new or unusual features. Building structures have been the subject of intense study for at least 100 years.
Structural safety is thus closely related to the practice of structural engineering.
Building codes can add little beyond confirming which design code is to be regarded as the basis for determining compliance with the bylaw and in confirming, by reference to particular items, what degree of safety society wishes to ensure. It is a paradox that codes must be devised with the aid and expertise of the very people whom, in practice, they undertake to instruct. This must be regarded as a mature stage, however, in which safety can be left to the specialist practitioners. Safety in respect of health is not so well developed, but neither is it critical since accepted practices are generally well above the level at which there is concern for health today. Certain restrictions, however, need to be reaffirmed about hazards such as cross connections between supply and waste piping.