Sean Birrane is promoted to chief executive after a six-year stint as managing director.
He will oversee the rationalisation of the business into four key divisions: regeneration, construction, compliance and energy services.
Former chief executive and majority shareholder Steve Rawlings will remain a member of the board.
Rawlings founded Lakehouse in 1988 but will now dedicate more time to Building Lives – the social enterprise he founded in 2010 which focuses on supporting young people on the path to a career in construction.
Jeremy Simpson joins as chief financial officer from waste management business Shanks Group plc, where he was UK finance director before becoming group corporate development director.
Simon Howell has been appointed as group company secretary following four years as group company secretary and head of legal at May Gurney.
Former financial director Alan Cox moves into a new role as group corporate development director while Michael McMahon joins the board as managing director of Everwarm – the business he set up in 2011.
Carol Bailey and Dean Ball become managing directors of Lakehouse’s regeneration and construction divisions respectively.
Former pre-construction director Phil Tidmarsh becomes group commercial director.
Stuart Black, executive chairman at Lakehouse, said: “It is great news that Sean is taking up the role of chief executive – his long history in the industry coupled with his unwavering commitment to Lakehouse makes him the best candidate for the job.
“Sean will benefit from the support of Jeremy, Michael and Simon, who are fantastic new additions to a first-class team, and will work together to continue to strengthen our business as the economy recovers.”
Birrane said: “Having seen Lakehouse change and grow during my time here, I am excited to take on this role as we consolidate the progress we have achieved both organically and through strategic acquisitions.
“Lakehouse is going from strength to strength, but we can continue to build on our superb record in construction and regeneration, as well as diversifying and enhancing our margins further in compliance and energy services.
“Developing and refining our business through these four key divisions has helped clients to better understand our offer and gives our business clear direction.”