Waterloo Road is obviously a school in trouble, because in the opening scene a kid smashes a window, this connotes that he doesnt care about school property, suggesting that the school doesn't respect the students very well. The teachers dont do anything about this, this suggests that they also do not care and are only there for a job and money not to advise over the kids. They also smoke outside infront of the kids which sets a bad impression suggesting furthermore that they do not care about the students health.
All/most of the kids are not wearing typical school uniform, this suggests that they do not respect the school laws and neither to the teachers as they are hardly smart. This has obviously been going on for a while as at the end the headteacher loses it and starts throwing equipment and paper of the roof.