From AHMM’s base in London Simon leads a studio that works in the UK and internationally, engaging public and private clients in the exploration of a particular architecture’s potential to offer delight as well as utility. Simon works on a wide range of scales and typologies. Notable projects include the Angel, Tea and Yellow Buildings as well as Adelaide Wharf, the Saatchi Gallery and Chobham Academy. He recently completed White Collar Factory on Old Street, offices for Google and YouTube at Pancras Square, a tower at 240 Blackfriars, three mixed use projects on Regent Street for the Crown Estate, and an academic building for the University of Amsterdam. He is currently working on projects around the UK, in Europe, the US and India.

Simon is a Trustee of the London School of Architecture and has been chairman of the Architecture Foundation, a trustee of the Architecture Association Foundation, and a visiting professor at The Bartlett and Harvard Graduate School of Design. He has also been Vice President for Education at the Royal Institute of British Architects (RIBA) and a Chair of Design Review at the former Commission for Architecture and the Built Environment 

He was President of the RIBA from 2021 to 2023, and continues to serve as a member of the Institute's Board and as an RIBA Awards judge. 

Simon engages in the broader architectural discussion as a writer, critic, teacher, judge of competitions, frequent lecturer, examiner, advisor and commentator.