Contractors are being invited to bid for the main construction package on the $200m King Abdullah International Gardens in Riyadh.

The phase two package includes all external construction services on the 1.6-square-kilometre site, as well as the 100,000 sq m site for the main building. Bids are set to be submitted in May.

The development has been commissioned by the municipality of Riyadh. The local Omrania & Associates is providing site management and construction supervision for the project.

Detailed design, construction documentation and other building services were carried out by a joint venture of UK consultants Barton Willmore and Buro Happold.

Barton Willmore provided masterplanning, architecture and landscape design services, while Buro Happold provided structural engineering, building services and infrastructure engineering design.

The joint venture team was also responsible for the design of the infrastructure for King Abdullah International Gardens. This included earthworks, roads, footpaths, car parks, sewerage treatment systems as well as other utilities such as electricity, telecoms, gas and water.

The project’s centrepiece will be a 40-metre-high crescent-shaped plant laboratory and indoor botanical garden. The building’s roof will have a span of up to 90 metres and will be the world’s largest tensile fabric-covered structure.