Hi Lastbuilders
The reason why no switching unit is allowed in the enclosure is that the hotpress is prone to relatively high humidity levels. Over time it creates an oxide coating on the exposed wiring. This coating increases the resistance. I have seen this on a 4 year old house recently where, due to an improperly installed shower, high humidity levels ocurred between the drywall due to a serious leak. This was on a properly located switching unit!
The regs. are there because faults are found and need to be adressed. Having said this don't knock your electrician. Granted it is up to him to keep current,(excuse the pun) and a responsable tradesman will do so. But this does not necessarily mean he does not know what he is doing.