Neall has been in the post since 2001 and will now focus his attention on parent company One Group Construction where he has also been group chief executive since 2008.
Jackson contract director Brian Crofton has now been promoted to managing director.
Neall said: “The time has come for me to step back and focus fully on all of our companies.
“Whilst it’s tough for me to do, this is great news for Jackson as it needs the drive of a fully focused, young management team who aren’t too set in their ways.
“After 17 years in post, I’m definitely an ‘Old Dog’ so I need to get out of the way a little.
“Unlike some of our competitors, Jackson is in a very strong position financially, and we’ve delivered some fantastic results over the past few years.
“It therefore feels like the right time to hand over the reins whilst the business is performing well.
“Brian has been with the company since 2001 and has exceptional operational and commercial experience.
“He will bring that focus to the position as well as a fresh set of eyes on how we do things and where we’re heading.
“Most importantly, he is also a really good guy with great family support and I wouldn’t be trusting him with my baby if that wasn’t the case.”
Neall will remain chairman of the One Group Construction Board which turns over £160m per year and includes Jackson Civil Engineering Group, Emmitt Plant, SEH Ipswich, SEH Surfacing, SEHBAC Home Improvements, SEH Property and Developments, SEH Commercial, SEH French Construction and SEH French Building.