The performing arts students will now use the school hall and the special needs students have been moved to other classrooms.
The science block now has three modern science labs with flexible work spaces, alongside refurbished offices and preparation areas for staff.
"Science is a particularly successful subject here," said Mr Hamill. "It's great to have the facilities to match the quality of teachers.
"The classrooms have the capacity to support all students in developing their scientific literacy, as well as empowering our aspiring 21st century scientists. The amenities provide quality, flexible learning and teaching spaces which are supported by excellent teacher work spaces and resource facilities."
Head of science at Melville, Sangita Achary said science was a strong subject at the school and former students had gone on to work in dentistry, ophthalmology, in labs and as science teachers.
The recreation centre had a new floor installed, external cladding replaced and a new roof.
A specialist student fitness centre beneath the school's Glenice Gallagher Library is due to open within the next month.
A $40,000 donation from John and Glenice Gallagher will be spent on a purpose-built facility to support students in developing their fitness and wellbeing. It will also support aspiring athletes.