The company will continue under the same leadership team led by chairman Tony Iles, who founded the business in 1999 with his wife Debby Iles, but his majority ownership has been relinquished.
The employee-owned trustee board will include Tony Iles, and two employees appointed by the wider team. In addition there will be an employee representative appointed by the holding company board to be employee liaison officer.
Mr Iles said: "This is a really exciting move for Tonic Construction, enabling us to realise our ambition to become a trans-generational business and guarantee intercompany loyalty and succession.
“The collective ownership by all the team, secures the future of the business and our core values, meaning we can long outlast the founders and senior team without the threat of a takeover or sale that could result in a dramatic change in business culture. This will preserve our valuable long-term relationships which sit at the heart of everything we do.
“We can now build confidently for the future, continuing to offer the whole team the very best opportunities. Thereby preparing to serve our clients’ next generation and by widening the ownership of the business to its employees it secures the future of the business, including its ethos, values and employees.”
Tony Iles said that the employee-owned trust business model was “probably the fairest and strongest business model in current times and should become the lifeblood of business in all sectors”.
Professional advice was supplied by law firm Fieldfisher and accountant BDO.