Kelvin is Senior Visiting Fellow at the Department of Land Economy, Cambridge. He is an examining inspector dealing with major infrastructure projects for the Planning Inspectorate. Kelvin has dealt with a power station in Lincolnshire, and an off-shore windfarm in Morecombe Bay. He is a Member of the Board of Trustees of Shelter and a member of the Committee of Shelter Scotland and also a member of the Department for Communities and Local Government’s Planning Sounding Board.

Kelvin has been a Specialist Adviser to the House of Commons Communities and Local Government Select Committee, having worked on that Committee's 2011 and 2014 Inquiries into the National Planning Policy Framework. Previously, Chief Policy Adviser to the Royal Town Planning Institute (RTPI).

He writes and talks on planning, having recently delivered the keynote address at the Oxford Planning Law Conference, and edited the Interface section of the RTPI Centenary edition of Planning Theory and Practice. A ‘Distinguished Professional’ Member of the Chartered Institute of Housing, and a Fellow of the Royal Town Planning Institute, he is named in Planning magazine’s list as one of the 100 most influential people in planning.