At the recent GE Basements and Underground Structures conference, industry leaders Michael O'Hagan of Keltbray and Stuart Vaughan of Wentworth explored the intricate challenges facing the £300 million Salisbury Square development in London. Featured prominently in their discussion was the construction of a deepened basement within this significant project, situated amid a complex urban environment. The site previously hosted nine different buildings, leading to a varied construction landscape, which further complicated the excavation process.

Significantly, the basement's proximity to a listed building and surrounding structures, notably a public house and the office building at 8 Salisbury Square, imposed stringent requirements on the project team. Built on a foundation of uncertainties, the project's complexities included undetermined service locations around the perimeter, complicating efforts to pile and excavate while ensuring the continued functionality of nearby assets. To navigate these challenges, the team relied on meticulous investigation and collaborative strategies to de-risk the project.

Notably, the Salisbury Square project has embraced innovative sustainability measures, with the City of London Corporation having announced the completion of the first of over 60 geothermal boreholes in July 2023. This system marks a significant advancement as the first standalone heating and cooling infrastructure in the Square Mile, aiming to mitigate carbon emissions and lessen dependency on gas. It aligns with the Corporation’s ambitious Net Zero 2040 target, reflecting a broader industry trend of integrating advanced environmental practices in urban development.

The project, which commenced construction in October 2022, is poised to become a civic landmark. It will feature a state-of-the-art facility for His Majesty’s Courts and Tribunals Service, housing the City of London Law Courts alongside a new headquarters for the City of London Police. Designed by Eric Parry Architects, this ambitious scheme will encompass 45,785 square metres of space, enhancing the existing legal infrastructure while focusing on high-stakes crimes such as fraud and cybercrime.

However, the project has not been without controversy. Critics have raised concerns regarding the environmental impact of demolishing six historic buildings to make way for the new construction. An analysis claimed that this approach could result in an upfront carbon footprint more than 40% higher than a strategy focused on retrofitting. Advocates for sustainability argue that preserving existing structures could be a more effective means of achieving lower emissions and aligning with climate targets.

In June 2024, the City of London Corporation celebrated the project's notable milestone, marking the completion of the excavation phase—a step referred to as 'Bottoming Out.' This achievement underscores the project's commitment to delivering a facility with eighteen courtrooms, merging existing courts in the Square Mile—excluding the Old Bailey—into one central building. As the project progresses towards its 2026 completion date, it embodies the dual imperatives of innovation and heritage preservation in one of London's most critical urban developments.

With the impending completion of this high-profile initiative, the Salisbury Square development is positioned to bolster the City of London’s status as a global hub for business, law, and justice while attempting to address pressing sustainability challenges.

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Source: Noah Wire Services