AmTrust, a New York-based specialty insurer, is planning a roughly 300-metre, 70-storey tower to replace Exchequer Court at 33 St Mary Axe in the City of London, a scheme that matters to building and architecture professionals because it would add about 1 million sq ft of offices to the Square Mile’s eastern tall-building cluster. AmTrust paid £105 million for the existing building in early 2017.

AmTrust owns Exchequer Court, a stone-fronted block of around six floors that is also the registered office of its UK carrier, AmTrust Specialty Limited.

Sir George Iacobescu, who spent 36 years at Canary Wharf and stepped down as chair of Canary Wharf Group in July 2024, is steering the plans.

A public consultation is expected to open this month, with a planning application to the City of London Corporation due in early 2027 and completion targeted for 2033.

Chaya Cooperberg, chief people and communications officer at AmTrust, said: “This is a long-term commitment to London we are making.”

The structural driver is the City’s office target, with its City Plan 2040 calling for at least 1.2 million square metres of net additional office space between 2021 and 2040, and the eastern cluster around St Mary Axe expected to deliver much of it.

For the sector, the timing matters because the neighbouring One London tower, at 74 storeys and 309.6 metres, won approval in December 2024 and also targets completion in 2033, according to Insurance Business, so two supertall schemes could land in the same year.

CoStar reports the tower as a 70-storey scheme of about 1 million sq ft, and Construction Magazine says planning is expected in 2027, which gives consultants a long lead time before any appointments.

The broader implication for the sector is that demolition-and-rebuild of mid-rise City offices is returning as an owner-led route to top-tier space, a pattern likely to shape design, demolition and structural commissions in the cluster.

Source: Insurance Business / CoStar / Construction Magazine / City of London Corporation