I use the word seclusion very deliberately in place of isolation as the latter has a connotation of a punitive approach, whereas the former suggests a supportive approach.
Many schools, in particular secondaries, use isolation as a punitive and demeaning program to remove children from the classroom environment to what can only be considered a pin down environment without necessarily going through the process of discussion, review and reflection that should really take place whenever behaviour causes a problem in the classroom.
I have witnessed members of staff sending children to isolation for some of the most trivial 'offences' and the school policy then demands that this child behaves perfectly for the whole day, despite perhaps feeling very poorly treated.
In addition to this, the actions of a single member of staff can effectively prevent a child from accessing the curriculum they are entitled to for the remainder of that day. I find this approach incredibly difficult to rationalise other than to suggest that it is done to frustrate, annoy and further disaffect the individual. In my opinion, it has actually no place in education institutions and the sooner it is viewed in the same way we view corporal punishment, the better. It is in effect internal exclusion initiated by the class teacher for whatever reason they choose - surely this cannot be correct.
There are many times that challenging children will require more than time out from the classroom. Indeed, they may come across individuals within a designated time out space like the Green room who could cause even more problems by winding up and commenting inappropriately. In this situation, it is probably better for all parties if there can be an additional area where some seclusion can take place. This may need to be supervised by somebody from the SMT and may be away from the initial time out area.