Without knowing what you are about, your question is akin to how long is a piece of string. As you have seen, the RIBA, who establish architects fee base, are vague. If you have not employed an architect before, be warned that you are stepping into a black bottomless pit so far as money is concerned, that many people do not like the work of their architect, and that the appointment of an architect often leads to immense waste costs, anguish, much waste time, disappointment, more huge costs, disputes and court. You must be very clear and exact about what you expect an architect to do and what you will pay if the work is acceptable to you only, and before you appoint one you should ask yoursel 50 times a day for six weeks "Do I need an architect"? taking a cold shower each time afterwards. It is a very wishee-washee profession. Ball-park fee costs are given in most builders price books (at your local library?) and the Royal Institution of Chartered Surveyors - 0870 333 1600 - will also guide you towards where cost indications can be found.