The founder of Scottish construction consultancy Riddell PM is retiring after 35 years and handing over the business reins to his sons.

Dave Riddell and his wife Doreen are stepping down from their active roles, with their sons Gavin and Michael taking over. To assist with a smooth transition, the senior Mr Riddell will for a short period take on the role of chairman.

After graduating in 1972 with a degree in civil engineering from Heriot-Watt University, Dave Riddell embarked on a varied career in construction, rising to board level during an 11-year period with Morrison Construction.

He set up Riddell PM in Dunfermline in 1989 and has since led the company to completion on more than 5,000 projects, encompassing services such as project management and construction management principal designer, as well as producing building manuals covering operations and maintenance, fire safety, and the company's electronic Pyramid Digital manuals.

READ MORE: All jobs lost as JS Crawford goes into liquidation

“I would like to thank all of our management and staff, both past and present for the remarkable contribution they have made to the successful development and growth of the business over all of these many years," Mr Riddell said. "I could not have done it without you.”

His sons Gavin and Michael will join existing director Mark Grant on the company's board of directors to steer the business, which employs 18 people, through the next phase of growth. The consultancy currently focuses on project management across several industry sectors including building construction, water supply and treatment, manufacturing, airport and railway infrastructure, renewable energy, finance and banking, healthcare, sport and leisure, and education.

The company added that while Dave Riddell's retirement marks the end of an era, it also signals the beginning of an "exciting new chapter" for Riddell PM.