Public Health England has selected three contractors to build its new £400m science campus and headquarters in Harlow, Essex.
Wates secured two of the four lots available, which will see it oversee the refurbishment of the main building as well as the arrivals, administration and logistics facilities.
Kier won the £160m package to deliver a new specialist bioscience laboratory at the site.
The final lot covering site-wide infrastructure, external works and energy centre was awarded to VolkerFitzpatrick.
Public Health England said initial work on the project would start next month, with the three contractors preparing the site for construction and liaising with existing design teams.
Construction on the scheme will get fully under way in 2019, with the first occupants moving in during 2021.
Kier executive director for construction and infrastructure services Nigel Brook said: “This £160m project is another significant award for Kier in bioscience, building on our track record as a specialist delivery partner in the sector.
“[Our] projects have included biomedical research facilities for the University of Cambridge with Project Capella and the Sainsbury laboratory, as well as the state-of-the-art Derriford Research Facility for Plymouth University.”