Kollar House is one of the most recent additions to Girls Grammar, completed in 2000, it was built to house the Senior boarding girls.

It was built on the site of the old tennis courts, and is a large, modern building surrounded by picturesque gardens, designed to provide the Senior girls with high standard boarding facilities, comparable with the best girls boarding schools throughout Australia.

Kollar is a two-storey building which has thirty single rooms on each floor, which currently house the Year 11 and 12 boarding girls. Each room has its own phone line and internet access, as well as built-in desks and large lockable cupboards to store all the girls belongings. On each floor is also a large, open common room, where girls can relax or study with their friends. Next to the common room is the kitchen, where the girls are able to store food in the fridge or prepare drinks and snacks. In Kollar, there are also staff flats, as well as a PA system to announce messages to all the girls. Also on each floor is an outside veranda with barbecue facilities overlooking the gardens and the school oval. To the rear of Kollar is a car-park which is for the use of staff and students.