St. Martins School was built in 1860 at the same time as Bishops Gate Lodge. The building was originally single storey and consisted of just one room, 32 feet by 18 feet, with two entrances, a porch and a lobby. It is built in the Lovelace style with brick and flint and decorative tiles. It has a slate roof with open beams beneath and a basement. It also had raised tiers of desks and benches at one end. Attached to the north side of the main building was the schoolmistresss house. In 1891 a smaller infants classroom, 14 feet by 16 feet was added onto the school house and two years later a new porch and lobby were added to the south side.
People who went to the school when they were children said that it was extremely cold in the winter, in spite of having a stove in one corner. Children had to walk to school, often in the pouring rain, their outdoor clothes were then hung around the stove creating clouds of steam! If anyone was not feeling well, they were allowed to sit near the stove which was a great treat!