Grantleigh offers boarding to boys from Grade 4 to 12 and girls from Grade 8 to 12.  This boarding establishment is far from typical, as it accommodates only 31 boys and 20 girls, making it a home-from-home experience.

The boys are housed in Grant House, which consists of  custom-built small cottages around a quadrangle with a pool and common room, which is equipped with a TV and pool table for recreation.  The boys also have easy access to the school tennis court, and ball games are a big part of life at Grant House.

Each room is well appointed with a desk and chair to allow the boys to study in their own environment.  Structured homework also takes place in the common room and is supervised by the resident staff, who are available to see to the personal needs of all the boys.  The houseparent, Mr Dewald Kruger, and his family live in one of the cottages and are always available for the boys. 

The original farm house of Fred and Renett Grant (the founders of the school) is today known as Founders' House – the girls' boarding house.  It is set in a lush garden with its own swimming pool and tennis court.  The emblem of the house portrays the resident eagle owls and beautiful fig tree.  A family atmosphere prevails at Founders' House.  The rooms are spacious and each girl is allowed to make her space her own.

Structured prep times allow the girls to complete school assignments.  Staff on duty are always willing to assist the girls.  The girls enjoy socialising in the common room – reading, playing board games and even watching their favourite TV programmes.  Structure is very important and discipline is closely monitored.

The girls enjoy all their meals in the dining room together with the boys from Grant House and this gives the staff and boarders from both houses time to interact with one another and there is a real sense of camaraderie and caring amongst the boarding establishment 'family'.

The head of house collects material from all boarders – jokes, news, advice – and then she compiles it into a term newsletter – Flexitime at Founders – which builds a lot of spirit among the students.

The house parent, Mrs Marita Veater, and her family live at Founders' House.  This creates a friendly family atmosphere which ensures that each of the 18 girls has a home-away-from-home experience.