One London joins Shard as UKs joint-tallest: St Helens Tower deconstruction and the City of London skyline

Overview

The B1M tours Londons evolving skyline, highlighting One London and the deconstruction of St Helens Tower, set within the historic and busy Square Mile. The video explains height ambitions, aviation restrictions, and how planning, archaeology, and urban context interact as construction progresses.

Key insights

• The 309.6 m aviation ceiling confines Londons skyline, allowing a joint tallest status with the Shard.
• One London aims to add substantial office space while incorporating public features such as a viewing gallery and public garden.
• St Helens Tower is being dismantled using a top-down, suspended-floor approach, protected by a temporary white wrap and extensive site safety measures.
• Contextual planning tools, including a 1 to 500 scale City of London model, help evaluate new buildings within the historic cluster.

Introduction: London as a living city

The video frames London as a city of contrasts, where a thousand-year history meets rapid modern development. It begins with a comparison between The Shard, towering since 2012, and the emerging One London project which aspires to reach an identical height of 309.6 metres. This precision is not arbitrary but dictated by an aviation ceiling that governs how high any London structure can rise without compromising airspace safety. The discussion situates these plans within Londons enduring urban fabric, where ancient ruins, protected sightlines, and dense pedestrian activity shape what can be built and how.

One London: height, space and public realm

Plans for One London originally projected 305 metres and 73 storeys, but subsequent updates refined the height to 309.6 metres, aligning with the Shard and making it a joint tallest structure in the UK. Stanhope, the development managers, emphasise that this extension increases floor area by about 30 and unlocks public features including the worlds tallest public viewing gallery and a garden projecting from the 11th floor. The development is praised for efficient use of space, with 154,000 square metres of commercial space and premium Grey Day offices, while addressing the rising demand for office real estate in the City post pandemic.

City of London: history, planning, and context

The presenter uses the London Centre model to illustrate how new tall buildings will sit within the Citys dense cluster. The model reveals how much of Londons skyline a single tower could dominate when context is considered. The Citys long history, from Roman Londinium through to the medieval era and the 1666 Great Fire, is shown as a reminder of the spaces, lines, and sightlines that planners must respect. The video stresses that construction on such a site is not simply a matter of height; it requires careful attention to surrounding heritage assets and public spaces, including views of St Pauls and Westminster.

St Helens Tower: a deconstruction case study

The narrative then shifts to the deconstruction of St Helens Tower, or Aviva Tower, built in 1989. Unlike typical buildings that are demolished from the ground up, this structure features a suspended, top-down assembly that necessitated a unique approach to deconstruction. A central concrete core supports a cantilevered roof level, with floors suspended by steel trusses during the early phases. The deconstruction strategy reverses the original construction logic, enabling controlled removal floor by floor while maintaining the citys safety and minimizing disruption to surrounding historic fabric.

Engineering logistics: precision in a crowded city

Before any dismantling could begin, more than 700 tonnes of steel props were installed on each floor to transfer and reconfigure loads. The external shell is being converted into a temporary exoskeleton that resupports structural elements in a manner similar to a conventional building, allowing floor-by-floor deconstruction while maintaining stability. The team describes the sum of the steel used across both halves of the tower as 700 tonnes, underscoring the magnitude of the operation and the meticulous planning required for safety in a busy urban environment.

Site protection, archaeology and public life

In central London, protecting nearby historic structures, protected sightlines, and the thousands of residents and visitors is paramount. The video highlights dust, noise, and vibration monitoring as essential components of site safety. It also references UK laws that pause construction when archaeological finds emerge, with recent delays at 85 Gracechurch Street illustrating how discoveries can shape design iterations. The London skyline is thus portrayed as a dynamic interface between living city life and the built environment, a place where public life continues even as major works progress above.

What the future holds

With St Helens deconstruction underway and One London moving toward construction after demolition ends in 2027, the Citys skyline is set for transformation. The video also notes Londons ongoing need for space to accommodate business activity and the return of office demand post pandemic, suggesting the One London project is not only about height but about alleviating space constraints in the Square Mile. Finally, the sponsor message for Dropbox is acknowledged, but the focus remains on the architectural and urban planning themes that define Londons evolving skyline.