Mark Sumner, director of Levitt Bernstein's landscape architecture division, has died at the age of 46.
Sumner joined Levitt Bernstein from BDP in 1991 and built up a substantial landscape-design group within the east London-based practice.
He brought a wide portfolio of work to the firm, ranging from public spaces including Shoreditch Park and Evergreen Square in Hackney, to private housing such as Pimlico Village in Westminster.
Sumner's work also included the winning competition entry for the Hermitage, a memorial park beside the Thames to commemorate the victims of the Blitz; the Genocide Memorial Sites in Rwanda; and a shortlisting for the 7 July London bombing memorial in Hyde Park.
Hugh Geddes, director of Levitt Bernstein, said: 'The gentle kindness which characterised Mark's personal relationships made him skilled and sympathetic in consultation with end-users from housing-estate tenants to Rwandan survivors.
'Mark was easy to love and he will be truly missed by everyone who knew and worked with him.'