Jon Atkinson joins as project manager from Simons in Lincoln where he held the same role.
John Cooper has been appointed as strategic project manager after leaving Interserve where he was project manager.
Matthew Sargent also joins as design manager with responsibility for managing and coordinating building design.
Sargent was previously with Wilmott Dixon Housing and has specialist design expertise in retirement villages, housing estate regeneration and extra care and care homes.
Stepnell managing director Mark Wakeford: “We are delighted to have made these three appointments. Jon, John and Matthew bring valuable construction expertise and skills-sets to our business and we are extremely pleased that they will be helping in our continuing delivery of high-quality projects for our clients.”