Lennon is an Associate Professor in Real Estate Economics and Finance at The University of Hong Kong. He is a General Practice Surveyor (Valuer) by profession. His principal research interests are in new institutional economics (NIE) and urban studies. Lennon was a Senior Fulbright Scholar at The University of Washington. He also held visiting faculty posts at the Law School and the Booth School of Business in The University of Chicago. His study has been published in the Journal of Law & Economics, Habitat International, Cities, Land Use Studies and Urban Studies etc. Lennon is an editor of the Journal of Housing and the Built Environment.  He was also a co-guest editor of two special issues of the Habitat International on Low Carbon Cities and Institutional Innovations.  Lennon is an awardee of Li Ka Shing Prize (HKU), and Ronald Coase Prize (International Society for New Institutional Economics).  In 2003, Lennon was named a City Hero by the HKSAR Government because of his efforts to combat the outbreak of epidemic SARS.  He was a Co-Investigator of a Cheif Executive Commnity Project entitled SMILE under the auspices of the Hong Kong Jockey Club.

Lennon is a General Practice Surveyor (Valuer / Appraiser) by profession.  He was an enterpreneur and an active consultant when he was a faculty member of The Hong Kong Polytechnic University. Major clients that Lennon served include the HKSAR Government (Central Policy Unit, Works Bureau, Estate Agents Authority), quasi-government bodies (Consumer Council, Hong Kong Examinations and Assessments Authority), think-tanks and professional bodies (Bauhinia Foundations, Hong Kong Institute of Surveyors), as well as private companies (HSBC, MTRC, Chesterton, Commercial Press and Oxford University Press etc).

For services to the communities, Lennon is a Council Member of the General Practice Division of the Hong Kong Institution of Surveyors, and also an appointed member of the Private Columbaria Appeal Board, Buildings Appeal Tribunal, Real Estate Services Training Board, Professional Development Committee of the Estate Agents Authority etc.  Lennon is an External Examiner of many surveying related programmes in local teritory institutions such as SPEED, SPACE and Open University.  He was a member of the Authorized Persons Registration Committee, and a panel member of the Hong Kong Council for Academic Accreditation & Vocational Qualifications.