The contractor worked with designer BDP on a proposal to replace the current building at GOSH, which marks phase four of the historic hospital’s redevelopment.
The partnership beat a proposal from Carillion and Eric Parry Architects and another from Skanska, Heatherwick Studio and Hok to clinch the deal.
The GOSH NHS Foundation Trust has now entered an early stage agreement with Sisk to allow further development work.
The new facility will be spread across four floors and contain 60 consulting rooms and 100 beds, as well as teaching rooms, a school and rooftop garden.
A spokesman for the trust told Construction News that it was working to submit a planning application in the coming months and that its target start date for construction was early 2020, subject to approval.
GOSH chief executive Peter Steer: “After comprehensive analysis and debate, the John Sisk & Son with BDP team led the field.
“Partly this was because of the quality of their concept design, which was really popular among the GOSH community when the design proposals were anonymously exhibited side by side.”
Sisk BDP Great Ormond Street Hospital phase four 1
GOSH said the proposal created “a welcoming, active frontage and an architectural expression of the activities taking place within”.
Construction News first reported on the scheme in August last year, when GOSH NHS Foundation Trust invited bidders to tender for the deal, which was then valued at £150m.
The hospital’s redevelopment will see two-thirds of the estate rebuilt over a 20-year period.
Phase three features the new £65m Zayed Centre for Research into Rare Disease in Children, which is being built by Skanska and is due to open in 2018.
CN revealed in June that Skanska had replaced Bouygues on the project after the contractor failed to agree terms with the client.
Phase 2B, the Premier Inn Clinical Building, is due to open next month.