St Mary’s Island

About this project

St Mary’s Island, located on the site of the former Royal Naval Dockyard, is being developed through a joint venture with the Homes and Communities Agency (HCA). Spanning 150 acres, the development will create a vibrant mixed-tenure community with approximately 1,700 new homes, shops, a school, community facilities, public open spaces, and a marina.

The project has adhered to very high standards of planning, design, and sustainability, which have been key to its success as a multi-award-winning scheme.

Historically, St Mary’s Island was heavily contaminated, requiring extensive remedial works. As a result, the site was left flat and featureless. To address this, structural landscaping and earth mounding were introduced across the island, providing shelter and enhancing the site’s visual appeal. In addition, flood defences were strengthened. However, several piles in Sectors 15/16 encountered obstructions that hindered their installation.

Building Design Consultants (BDC) was tasked with redesigning the substructure to enable the piles to be relocated, avoiding the obstructions in a practical and sustainable manner. Each pile and pile cap was modelled using spring rates corresponding to the final capacity of the pile/pile cap, allowing for a controlled 10mm settlement.