Starting as a project manager in 1992, Holmes was Mace’s 30th employee and in 2001 was part of the team that led Mace’s management buyout.
He went on to establish the Mace Consultancy business in the UK and then set up new businesses in cost consultancy and facilities management and established Mace in North America in 2011.
He is the longest serving member of the board.
Holmes said: “It has been a privilege to play my part in the development of this great company.
“Loyalty is an underused word these days, but it has been great fun and I leave the business with only fond memories – and look forward to seeing it continue to prosper in the future.”
In his role as deputy chairman, Holmes has been responsible for several key corporate functions, including human resources, responsible business and marketing and communications.
He has served as the board sponsor for climate change, he chaired Mace’s People and Talent Board and led the diversity and inclusion steering committee.
Holmes will continue on as chair of the Mace Operate global FM division, and will also take on a new role as the chief executive of the Mace’s independent charitable foundation.
Mark Reynolds, Mace Group’s chair and chief executive, said: “There can be few people in our industry who can claim to have had the impact that Mark has had over the past thirty years. He has been a foundational part of Mace’s success.
“Mark’s personal legacy, aside from the growth of Mace from a small project management consultancy to a global consultant and contractor, is his unwavering commitment to sustainability, inclusion and Mace’s role as a responsible employer.”