As per clause 3 (b) in your residential agreement - 'The Resident acknowledges that the Room is furnished with the Furniture. The Resident may not add any additional furniture, furnishings, or other items (including heaters, electric blankets, lights, extra beds or mattresses) to the Room without the approval of the University.'
Should you gain approval from the University please be aware that you'll be required to pay a removal, storage and/or disposable fee for the existing furniture.
If you have any further questions, please don't hesitate to contact us at accommodation.info@sydney.edu.au or (02) 9351 3322.