Facilities included purpose-built outdoor tennis courts which could be converted for netball, and sandpits for long-jumping. There was also an outdoor amphitheater used during the summer. In 1965-66 the school made use of its facilities for learners at the then new Crystal Palace International Sports Arena.
The original school hall had seating for 1,500 pupils
In Sedgehill's early days it catered for the needs of pupils between the ages of 11 to 18 years. All the boys and girls followed a general course of education for the first three years. During the third year parents were informed of the school's assessment of the abilities and aptitudes of each child; these factors, together with the parents' wishes, were given the most careful consideration when the time came for each pupil's allocation to one of the various courses. These were:
In 1971 the joint head of science at the school, Donnahadh O'Shea, was accused of causing an explosion on a train and injuring a 76 year old woman. The woman claimed she could not hear after the explosion, and said: "All the windows on the non-corridor side blew in. My suitcase came down from the rack, and my purse shot off on to the glass". O'Shea had thrown nitroglycerine from the train as it was going through a bridge. Special Branch found four tins of grey "pistol powder", primers and a 12-bore cartridge in O'Shea's locker at the school. They also found 45 tear gas cartridges at his home in Bishopsthorpe Road, Sydenham. O'Shea had denied he was on the train at the time of the explosion but was picked out by a passenger in an identification parade. He pleaded not guilty to possessing nitroglycerine, causing an explosion and wounding the 76 year old woman. He pleaded guilty to possessing prohibited ammunition without permission. O'Shea was found not guilty of possessing an explosive substance, causing an explosion and wounding the woman. He was convicted of possessing 2lb. of nitrocellulose powder and 3,454 priming caps. He was jailed for 12 months for possessing explosives.
A 1974 intake pupil, Lloyd Hall, was one of the tragic victims of the New Cross Fire of Sunday January 18 1981. The school has recently gained an arts mark and became a performing arts college. The school is now in federation with Forest Hill School (boys' school) and Sydenham School (girls' school), making a sixth-form federation known as Hillsyde.
The school is now planning to be rebuilt on the same site but on different parts of land. The construction of the new school building has now begun (summer 2007) and it is aimed to be completed by December 2008.
Pupils currently wear black blazers (as opposed to the former grey blazers), with the school emblem on the front. The emblem is a yellow shield with a lion inside and the words "Dominus Regnat" (the Lord reigns) underneath.
Pupils are grouped using a house system. Each House - 'Bristol', 'Lincoln', 'Salisbury' and 'York' - has its own coloured stripe on members' ties. These colours are blue, green, red and yellow, respectively. These ties replace the 'old school' tie of black and gold stripes. Those who are selected as prefects at the end of year 10 wear a special black tie with a regular pattern of the sedgehill logo printed on top.