I know it's no ideal but we have one classroom where the only available power point is 10 metres from the teacher's desk. I have run a heavy duty single extension lead to the desk and connect a 4-way extension lead to that. The maximum load is around 2.5A. Our HSO picked up on it during her annual inspection and says it is "overloaded".
I do believe it is bad practice to extend extensions but I don't know what the regulations say. Can anyone help please?