Codification changes as a response to disasters

![CDATA[Codes of practice are designed as guidance to professionals for design, management or planning. Such codes of practice are documents that give advice about minimum standards that are acceptable to a professional body. Standards bodies are organisations set up by a government and charged with producing documents that may be adopted by different bodies, including the legislature. Codes of practice are often incorporated into legislation as "deemed to satisfy" documents, or as a means of satisfying the requirements of legislation. Even when this is not the case, such documents are generally regarded as being "best practice," and it is often difficult for professionals to deviate from the requirements of a code. As a result, the process that leads to the changes in such documents is of paramount importance. Codes of practice are drawn up by people who are at the same time experts in their field of study, and who are charged with the responsibility of representing their professional body, or government. It is often assumed that the considerations of such a body would be dispassionate and impartial. In practice there are many reasons as to why such bodies must behave conservatively, and why the majority of codes of practice err heavily on the side of caution. In the case of a disaster, a committee seeking to vary a code of practice will often review facts well before sufficient data is available for a dispassionate view to form. In the case of extreme events, such as windstorms, tsunamis, or earthquakes, a rational view of the risk can only be ascertained when the probability of occurrence of the event has been established. The data set necessary for a high degree of confidence in such an estimate may not be forthcoming. Nevertheless, as a species, we humans require quick answers and so codification review committees will often base their judgement on "experience." The short human life span militates strongly against this approach being effective and as a result the decision making of code variation committees is constrained. In this paper the general process of codification is considered and the influences on committee members from different sources are discussed. Codification changes as a result of terrorism in the UK, Hong Kong's philosophy for design against typhoon exposure, and the US experience with the collapse of the World Trade Centre towers are used as examples.]]