Work on the new South Holland Health and Wellbeing Hub is due to start in May, the district council has said.
It now hopes to have the renovated Castle Sports Complex open by January 2027, slightly later than the initial opening plans.
Surveying and site preparation works will start in May with further ‘early external works’ to follow once a contractor has been appointed, South Holland District Council says.
Coun Gary Taylor, South Holland District Council’s project sponsor, said: “It is fantastic to see this transformational project taking shape, bringing high-quality leisure, exercise, sport and wellbeing facilities to South Holland and bucking the national trend.
“With works beginning soon, we are taking a major step forward in delivering something that will benefit the whole community for generations to come, and I can’t wait to see construction taking place.
“We will share more updates as we move towards construction and completion of this brilliant new centre.”