The Old Building was constructed between 1557 and 1586, after the school was granted the Royal Charter in 1552 by Edward VI. The building is a square shaped Tudor style building with a central courtyard and three principal rooms: the School Room on the ground floor, and Big School, otherwise known as the Great Chamber, and the Chained Library, which is also the Headmaster's Study. In Big School, along the beams supporting the roof, there are names of people who have been influential in the school's history. Recent development has taken place at the back of the Old Building. The old gymnasium has been converted into a Sixth Form Centre and the Victorian science laboratories (some of the earliest in the country) have been converted to the Art School.
Allen House stood opposite the school from the late seventeenth century until 1964. It was a large house set in extensive grounds that took its name from Anthony Allen, Master of Chancery and Mayor of Guildford in 1740.
The building had many associations with the School. It was used as a boarding house between 1866-74. In 1914, the grounds were purchased by HA Powell, and given to the school as playing fields. From 1918, Allen House was rented for use by the Grammar School and in 1921 it was purchased by Surrey County Council. It continued to be used by the RGS until its demolition in 1964.
The New Building
The construction of the New Building was begun in 1958 on the Allen House Fields. This was the first of three stages, the last of which was completed in 1963. The New Building consisted of a gymnasium, assembly hall, dining hall and kitchens, caretaker's flat, staff common rooms, junior library, cloakrooms and changing rooms, eight classrooms, science lecture theatre, five science laboratories, geography and art rooms, and various offices, stores and smaller rooms.
Over the years, many extensions have been added. These include new science and technology laboratories and the Stainer Wing, which houses the Modern Languages and English departments. With the construction of the new sports centre completed, the gymnasium was converted into a multi-purpose auditorium where numerous drama productions, lectures and concerts are staged. The newest extension is to the front of the School, providing a new reception area and foyer, an extension to the Library and meeting rooms.
The North Building
The North Building was completed in 2003 and houses the Sports Centre, fitness suite, further classrooms and the drama studio. Adjacent to the Sports Centre is a floodlit all-weather training area under which is the rifle range.