The Science and HSIE Building – named The Mallik Centre was the School's thirteenth building.
Work began in 2005 on the new science building on the space occupied by two tennis courts and the school bus shelters.
The architects were Rick Butler & Associates and the builder was Paynter Dixon Constructions.
The Mallik Centre is named after a Foundation family; Mary and Raj, Mallik. The Mallik family supported the idea of establishing an independent coeducational school in the Hills area and one of the 80 families that went Guarantors to the bank to secure the school loan. Their involvement with The Hills Grammar School began as foundation parents in 1982 with both of their children completing their schooling at Hills. Dr Arun Mallik joined the School Council in 1994 and was elected to the position of Chairman in 1995 serving the school for 10 years. Dr Mallik gave generously of his time, expertise and financial resources to support the development of the School. His courage and commitment was seen by all when in the final days of his life, he insisted on giving his tenth and last Chairman's Address at Speech Night. He died on 22 December 2004. At the Dedication and Naming of the Science and HSIE building on 27 April 2007, Mrs Mary Mallik gave the response address.