I don't think so. For one, there's a lot of overlap between many of these questions, and part of it comes down to perspective. For instance, is "when" really different from "where?"
Tanks a lot Anjali Nilkanthappa Shete Anjay kumar Mishra Amina Khalil Oliver F. Ricardo Mohammadreza Habibi Sergio Salimbeni Artur Braun Dariusz Prokopowicz
Unlike some pure sciences, architecture is more of a hybrid integration of arts, science, mathematics, and common sense to response to 'How' to bring into existence something that is in the mind, paper, and computer. Being an integrated discipline, depending on the contexts, the answer may change. 'Why' could be important to answer various curiosities in the process of design, in the details and in making design decisions that requires basic common sense justification of a plethora of parameters. Why ostensibly answer most questions, in the process of design.
Let me articulate a little further, if I may. It can also depend on what does one mean by 'Why'? For instances, Why could respond to primal shelter needs, or the most urgent and necessary needs, etc. That sounds noble and all, but, in reality designers rarely decide why a client should need a house, office, school, library, chair, stool, or table, etc. In fact, the designer wishes these buildings to come into existence, and conceptualized ways of making it come into existence, and may have little or no say in the matter. In these cases, the best the designer does is satisfice the Where, Who, What, and When to the best of his capabilities. So, in these pragmatical sense, 'Why' is the least important.
1. What may address form, function, and aesthetics;
2. When could be most relevant for some who might believe architecture to be the will of the epoch and era;
3. Who may be appropriate to address socio-economically responsible agendas;
4. 'Where' could be most relevant to the environmental concerns.