Mt Albert Grammar School will open its first boarding facility for female students in 2018.

The school has acquired a former rest home in nearby Lloyd Ave, Mt Albert, and will spend next year renovating it in preparation for its first intake of up to 30 girls. They will be a mix of New Zealand and international students.

Headmaster Patrick Drumm said the school had run a boarding hostel for boys for the past 90 years, and the new facility enabled the school to provide equal opportunity for girls from outside its zone to attend Mt Albert Grammar.

"MAGS has a long history of offering our quality education to boy students from throughout the North Island. Now their sisters, and the daughters of former students, will have the opportunity to also board with us," Drumm said.

The chairman of the board of trustees, Greg Moyle, said the ability to host girls from outside the school's zone complemented other initiatives, such as the development of the ASB MAGS Farm to promote careers in the primary sector to urban students.

"MAGS' new AgriBusiness course is ideal for students keen to pursue a career in New Zealand's primary industries. MAGS is the only school in Auckland offering the course, so girls may wish to board with us to have that educational opportunity."

Drumm said demand for places at the school was unprecedented from inside and outside its zone - the roll was due to rise to 2800 next year, making MAGS the second-largest high school in the country. Rangitoto College is the largest.

It was rare for a suitable facility for a hostel to become available, and this property was in a safe residential street only six minutes walk from the school. It is planned that the MAGS Foundation will take over the hostel's ownership.