In 1942 the Canterbury Education Board needed school sites to cater for the increasing population in the Merivale area. Unable to acquire the McDougall Estate, a less desirable property owned by Sir Robert Heaton Rhodes was purchased under the Public Works Act. Road frontages had already been sold for private dwellings and the site was confined to the rear area. The buildings, then under military occupation, were described as old, obsolete and in poor condition. The final purchase took place on 23 August 1945, over objections by the St Andrews School Board of Governors. $41,900 plus costs was paid in compensation to Sir Heaton Rhodes.
In 1948 the Rhodes homestead was converted into a school for boys and was first known in the records as the Elmwood School. On the first of December that year the Education Board finally approved the building of a new school on the homestead grounds, to be known as the Elmwood Intermediate School, with 16 classrooms, no hall, limited manual facilities and to be designed by city architect, Mr G. Griffiths. Thirty months later working drawings were finally approved and Elmwood, Fendalton, St Albans, Waimairi, Wairakei Road and Papanui primary schools were designated as contributing schools.
A month later the name was changed to Heaton Intermediate School. Vigorous objections were raised by the Fendalton and Papanui School Committees and they were removed from the list of contributing schools when two further schools were planned. Forecast roll numbers at that time were from 719 in 1953 to 780 in 1956.
In May 1951 Cabinet finally approved the necessary expenditure for 19 rooms. The school was designated a Normal school for the training of student teachers, with a maximum roll of 665 pupils. After vigorous representations by the C.E.B. a gymnasium / hall was finally approved and provision made for manual rooms. The tender was let to the Fletcher Construction Company for 48,136 sq ft (4,472 sq m) of buildings at a cost of $257,540, a further $13,160 for grounds development and $30,000 for heating.
Building commenced in 1953. When 10 classrooms were completed, classes were moved in and the old homestead and outbuildings were demolished to make room for further buildings. In 1954 the first girls were enrolled and in 1955 the contributing schools sent all their Form 1 and 2 pupils to the new school – the third intermediate in Christchurch.