[1] He joined the firm Ove Arup and Partners in London in 1952, where he worked on Coventry Cathedral with Basil Spence.
In his own words: Ahm was given great responsibility on this project, working directly with Ove Arup.
[2][3] He also worked on early conceptual design schemes for the Sydney Opera House, and worked on other projects, including Smithfield Market, London and Centre Pompidou, Paris – some of Ove Arup & Partners' most prestigious projects.
By winning the competition to design the Gateshead Viaduct in 1965, Ahm started the firm's new transport group, specialising in bridges.
Ahm was awarded the ICE's first gold medal in 1993; the same year he received a CBE for services to engineering.