He replaces Stephen Tomkins, who has left after nearly two years at the helm of the £225m turnover Abergavenny civil engineering and rail specialist.
Parr joins Griffiths after 23 years at Farrans Construction, first as a project manager, before taking the role of contracts manager. He joined the Farrans board in 2015 and became civil engineering director.
During his time at Farrans, Parr led on several major projects, including Northern Ireland’s £110m Project Alpha water treatment works and Glasgow’s £320m M80 Stepps to Hagg DBFO.