Mid-sixties Mr Allaart died and Mr Koenraad came to Rotterdam to run the office. He was a surveyor specialised in fire damage. The Rotterdam insurance bourse, more focussed on land and maritime transport, demanded a more typical Rotterdam surveyors office. In 1969 arose in that spirit Expertisebureau Groenendijk B.V., founded by Kees Groenendijk together with Messrs Burgers and Salters. In the seventies Kees Groenendijk Jr. joins the club. After having worked together with four surveyors for many years Kees den Ouden is employed to provide rejuvenation within the company.
In November 2010 Ben Groenendijk started at Groenendijk to bridge the period between two studies. He enjoyed the work so much that he decided to stay. April 2014 was an all-time low; at a young age (58) Kees Groenendijk Jr. died and the office was continued by Ben Groenendijk, the third generation in the family business.
In 2019 Groenendijk continued together under one roof with Hamer & van Hussen, but under Groenendijk's own company name.