The new facilities are being built by Integrated Health Projects (IHP), an alliance of Sir Robert McAlpine and Vinci Building.
The new units will each have 54 single en-suite rooms, replacing current facilities in Derby and Chesterfield that have dormitory accommodation.
They are part of Derbyshire Healthcare NHS Foundation Trust’s £150m ‘Making Room for Dignity’ programme – a government-funded programme to revamp mental health inpatient facilities in Derbyshire.
The projects are set to complete in 2024.
IHP regional director Chris Winspear said: “It’s rewarding to see the Trust’s vision of modern facilities that provide comfortable, dignified and therapeutic environments for their users, taking shape.”