One London: A landmark project shaping the capital’s next chapter

Aroland Holdings, advised by Perennial Holdings, Stanhope and Eric Parry Architects, has introduced plans for One London, a skyscraper set to become the tallest tower in the City of London.

Named One London and previously known as 1 Undershaft, the 309.6-metre skyscraper is expected to become the City of London’s tallest tower and the joint-tallest building in Western Europe when completed in 2033. The development, valued at more than £1 billion, is scheduled to begin construction in 2028 and will provide approximately 1.2 million square feet of predominantly office space.

Located at the prominent intersection of Leadenhall Street and St Mary Axe, the scheme received planning consent from the City of London Corporation in December 2025. Preparatory works are already underway, with the deconstruction of the existing St Helen’s Tower in progress. The appointment of a main contractor is expected later this year, marking the next major milestone in the project’s delivery.

Pua Seck Guan, Chairman and CEO of Perennial Holdings, described One London as a reflection of the company’s ambition to create developments with long-term international significance. He said the name represents the building’s intended status as a landmark address in one of the world’s most influential cities and added that the project is expected to support London’s position as a leading global business hub.

He said the project has been developed through collaboration with an experienced London development manager and a leading architect, with the aim of creating more than a conventional office building. The scheme is intended to place emphasis on wellbeing, environmental performance and public engagement, while contributing to the future development of the City of London.

David Camp, CEO of Stanhope, said One London is expected to become a distinctive addition to the city’s skyline and a sign of London’s continued importance as an international business centre. He pointed to demand for high-quality office space, noting that office leasing activity has strengthened and that availability of premium space in the City remains limited.

According to Camp, London does not lack office buildings overall, but faces a shortage of exceptional workplaces that help businesses attract talent, encourage collaboration and support growth. He said Stanhope’s approach over the past 35 years has focused on creating innovative buildings that redefine the workplace while becoming part of the city and its communities.

Eric Parry CBE, founder of Eric Parry Architects, described One London as a landmark building positioned at the heart of a city with a strong future. He reflected on London’s long history of growth and adaptation around the Square Mile.

Parry said the project comes at a significant moment in the City’s transformation, as London’s skyline becomes denser and more vertical. From the beginning, he envisioned the upper levels of the building as civic spaces accessible to the public rather than areas reserved only for corporate use. One London is designed to engage with the city at several levels, from the street and public gardens to outdoor terraces, educational spaces associated with the London Museum, and a public viewing gallery offering wide views across the capital.

He also highlighted the building’s architectural and environmental approach, including its carefully proportioned form and distinctive white exterior, which is intended to help reduce solar heat gain and improve energy efficiency. In his view, One London represents a model for tall buildings that combines commercial use with a meaningful contribution to the public realm.