Ir Hon graduated from the Department of Civil Engineering, University of Hong Kong in 1980. He also obtained a master degree in Public Administration from the University in 1997. He is a fellow of the Hong Kong Institution of Engineers and Chartered Institute of Arbitrators.
Ir Hon joined the Government as an Assistant Engineer in 1983. He was promoted to Chief Engineer in 1999, to Government Engineer in 2005 and to Principal Government Engineer in 2008. He was Project Manager of Hong Kong Island and Islands Development Office of the Civil Engineering and Development Department from 2008 to 2011. He has been Director of Civil Engineering and Development from January 2011 to April 2015 before his appointment as Permanent Secretary for Development (Works).
Ir Hon has retired from the service since October 2018. In January 2019, he has been appointed as an Adjunct Professor of the University of Hong Kong.