Birrell is currently practising as a solicitor in Melbourne and is a member of the Australian Institute of Company Directors and is on the Executive Council of the Victorian Employers Chamber of Commerce and Industry.
Birrell is currently practising as a solicitor in Melbourne and is the Chairman of Infrastructure Partnerships Australia, the nation's largest infrastructure advocacy body. He is a member of the Australian Institute of Company Directors and serves on the Executive Council of the Victorian Employers Chamber of Commerce and Industry.