He replaces Nick Goff, who is retiring as regional director of the Bristol-based business operation.
Chell, 49, who previously managed BAM’s Cardiff office, now leads a team of 185 people and a supply chain of around 1,000 firms.
During his time in charge of the Welsh business for BAM, Chell led 26 projects with a combined value above £300m.
He said: “The construction industry faces many challenges. The foremost challenge is creating trust with our clients and supply chain as we ourselves change and develop.
“We’ve achieved this so far by creating quality relationships as a result of our progressive and non-contractual manner. This makes us good partners and problem solvers for both the public and private sectors.
Chell takes up his position from 1 November and lives near Newport.