Garstang (1959–1974) and Dr A J Taylor (1974 to turning comprehensive) all of whom made significant contributions to the grammar school.

The proposed site was also near to an old gasometer, which would need to be dismantled at considerable cost for safety reasons, and alongside the busy A102 Blackwall Tunnel southern approach road.

With relocation ruled out, the Westcombe Park buildings were demolished in the summer of 2012 prior to construction of replacement buildings (completed in 2014), and the Maze Hill site was refurbished and remodelled; both phases used funding originally granted when the school was due to move to the Peninsula.

[7] Teachers also organised a series of strikes (eight up to 7 November 2018) in protest at the academisation process; over 1,000 people signed a petition and 300 families raised concerns about UST finances and suitability with the school's chair of governors; but more than 100 signed a separate letter supporting the improvement plans and criticising the teachers' industrial action.

[8] On 14 November, a Greenwich Council decision about academisation of John Roan was deferred to a meeting in December 2018.

The school is currently split over two campuses — Maze Hill, where the 1920s grade II listed neo-Georgian building (architects Percy Boothroyd Dannatt and Sir Banister Fletcher)[11] stands, and Westcombe Park — named after the roads on which they lie (respectively Maze Hill and Westcombe Park Road).

The foundation stone of the Maze Hill buildings was laid by Sir George Hopwood Hume MP, local politician and chairman of London County Council, in 1926.

The John Roan had four house teams, named after people of historic significance: Seacole, Da Vinci, Darwin and Stopes, named after Mary Seacole, Leonardo da Vinci, Charles Darwin and Marie Stopes.