In awarding RTA gold, the judges commended the project as "a beautiful realisation of the school's vision for the future while honouring its heritage. A conversation between past and future".
They said the folds, forms and creases made the building "confident, crafted, contemporary and respectful", making it a visually remarkable architectural piece.
By blending in beautifully with the surrounding landscape of existing buildings, the judges said it had inspiring, exciting and faultless forms that slot into context.
"A beautiful and confident design, that contributes meaningfully to the school community."
Grant Muirhead, Whanganui Collegiate's deputy headmaster, said the school was particularly proud that its buildings have received recognition and the Whanganui community should also feel a sense of pride.
"Both building projects have required a lot of energy and have added tremendous value to the school and how it operates."
Muirhead said the positioning of the administration building had changed the way parents, students and visitors are received.
"Instead of being tucked away, the administration building is in the centre of the school which gives it a fantastic outlook."
He said the school community was particularly pleased with the school library, a listed heritage building that had kept its traditional features but was also now a modern working environment.
"It is a particularly well-used facility by our students, both during the day and evening."
The awards, now in their 21st year, showcase work of excellence in graphics, spatial, interactive, product and motion design along with four boutique awards. It is the largest design awards programme in the Southern Hemisphere.
