Hopkinson started as an apprentice with Derbyshire steel company Chesterfield Cylinders, where he progressed over 15 years to become production engineering manager.
He then moved to Wrexham electrical contractor Lloyd Morris Electrical before before joining the board of South Yorkshire mechanical and electrical contractor L J Monks three years ago.
Hopkinson said: “Hargreaves is a long established contractor within the ventilation industry. With the support of Senior Plc, we intend to build upon this.”
“These are difficult times for the construction industry but we have an experienced board and executive team, a sound business with an excellent reputation and strong industry connections.
“There are unprecedented challenges, but I have no doubts that we are well placed to meet them and not only consolidate our position but grow as the economy improves.”