Warren is the national director of the HAMES SHARLEY Health Portfolio based in Perth, Western Australia, He oversees healthcare projects undertaken by HAMES SHARLEY throughout Australia and New Zealand. In addition to his formal qualifications in architecture, Warren has a master's degree in health administration and a post-graduate diploma in project facilitation.

During his career, he has undertaken health projects in all states of Australia and New Zealand, ranging from individual hospital departments through to leading the collaboration of architectural practices responsible for the master planning and design of the $2 billion Fiona Stanley Hospital in Perth.

Warren maintains an active interest in teaching and research through his role as an adjunct professor at the University of Western Australia in the School of Design and is an active member of the Council of Convocation for UWA, following his role as the Warden of Convocation for four years from 2013–2017. During the period 2005-12, he was a visiting professor in health facility planning and design in the Faculty of the Built Environment at the University of New South Wales, and an independent board member of the UNSW Research Centre for Health Assets Australasia.

Warren is the immediate past chair of the International Union of Architects Public Health Group (a work group comprising 62 countries), is as an advisory board member for the Health Environments Research & Design Journal, serves on the awards jury of the American Society for Critical Care Medicine, is a member of the Australian Health Design Council, and chairs the Special Interest Group for health facility planning and design of the Australasian College of Health Service Management.

For the past four years, he has also been a professional fellow of the Center for Health Systems & Design at Texas A&M University in the US with whom he is working to establish Australia’s first postgraduate course in health facility planning & design. Warren is a former state and national president of the Australian Institute of Architects and a former state and national chair of the Australian Council of Built Environment Design Professions (representing all architects, engineers, quantity surveyors, and project managers).

In January 2009, Warren was appointed as a member of the Order of Australia for his services to architecture and his contribution to the planning and design of major health facilities.

Interviewed by Moyez Jiwa.