UK's Tallest Building: The 1 Undershaft

Revised designs for the UK’s joint-tallest building have put the 309.7m skyscraper named the 1 Undershaft in the limelight. The tower has been in the headlines for the controversies imbued in it, recent being the latest proposals issued. The 74-storey tower in the heart of London is expected to be the same height as The Shard. These towers will dominate the capital’s skyline, making it a breathtaking scenery. However, the latest proposals have received numerous criticism as being inconsiderate and absurd.

The tabled proposal entails including a 7m-high digital screen in St Helen’s Square at the base of the structure. Critics notes that they will create an environment of surveillance due to the increased security measures to combat vandalism. The 1 Undershaft skyscraper is a design by Eric Parry Architects to replace the St Helen’s Tower. Approved in 2016, the building has always stalled but it has addressed some of it challenges to expedite construction.

The State of Affairs Regarding UK’s Tallest Building

The implementation of UK’s tallest building is one that aims to see that its intended height is completed effectively. Increased from 1,000ft (304.8m) to 1016ft, this made it the same height as the current holder for the tallest building in UK, The Shard. Moreover, it is expected that the structure will be positioned near prominent landmarks. These include prominent landmarks in London such as the Ladenhall Building and The Gherkin.

Various reports noted last year that the construction of the building would take five years. Based on this schedule, it is expected to be finished in 2029, subject to its new design being approved. The development is primarily focused on office space, but it will also include retail units and public areas. Furthermore, it will also include restaurants and cultural spaces on the 10^th floor. Plans also include a publicly accessible viewing gallery offering panoramic views of the city. It also includes educational galleries to be curated by the Museum of London.

The Mysteries Shrouding the 1 Undershaft Skyscraper

While UK’s tallest building has made significant strides, several key details are still unclear. While the design and purpose of the tower have been revealed, various issues are unclear. One of these is the types of businesses or tenants who will occupy the office space. Moreover, specifics about the retail and public amenities on offer remain vague. It is also uncertain how much of the building will be open to the public beyond the viewing gallery. Sustainability is a core element of the design but the exact details on the green technologies being implemented have not been fully disclosed.

While it is also expected to be a major landmark it is unclear how it will impact the surrounding area. This includes in terms of traffic, infrastructure or the overall aesthetic of the City of London. There is also a mystery of the most recent plans will be passed. The final design is still not yet certain, which adds up to the ongoing delays meaning it is uncertain it will open in 2029.

Status of UK’s Tallest Building

One Undershaft is set to share the status of the tallest skyscraper in London and the United Kingdom with The Shard if a request made to update the design and slightly increase the height of the building is approved. The request was submitted to the City of London by the project’s architect Eric Parry Architects.

Founded by Eric Owen Parry RA, a British architect, designer, writer and educator, Eric Parry Architects, is an award-winning global architecture, design, planning and strategic consultancy based in London. Some of the company’s notable schemes include 50 Fenchurch Street, No.1 Grosvenor Square, and One Liverpool Street.

According to the application, Eric Parry Architects seeks to increase the skyscraper’s height from 304.94 meters Above Ordnance Datum (AOD) to 309.6 meters AOD. The term Above Ordnance Datum (AOD) refers to a height above the Ordnance Datum. An ordnance datum (OD) on the other hand is defined as the vertical datum used by an ordnance survey as the basis for deriving altitudes on maps.

This increase in height would make One Undershaft the same height as the Shard, which is the UK’s current tallest building. The height of both buildings is determined by a Civil Aviation Authority safety policy that restricts the height of buildings in central London to 309.6 metres AOD.

In terms of storeys, the new plan proposes an increase of the building’s floors from 73 to 74.

Additional Changes Meant for The 1 Undershaft

According to planning documents, along with the increase in height, Eric Parry Architects proposed a change to the shape of the building from a cross-braced and tapered tower to a tower segmented into four vertical blocks. Reportedly, this change will in turn increase the usable floor area by 30%.

As part of the proposed changes, a public roof garden will be added on the 10th floor of the building. The garden will extend over a curved canopy above the corner of Leadenhall Street and St Mary Axe. Additionally, several winter gardens and external office terrace spaces covering an area of up to 1,530 m2 and 1,370 m2 respectively will be added. Furthermore, One Undershaft will get approximately 110,000 m2 of workspace up from 90,000 m2.

According to the One Undershaft development team, the changes to the design have been made to adapt to and respond “to post-pandemic markets and user demands”. The team, in addition to Eric Parry Architects, includes DP9 as the planning consultant, Kanda Consulting as the engagement consultant and Stanhope as the development lead.

SLA and WSP are also a part of the team as landscape architect and multi-disciplinary engineer respectively.

Noteworthy, the building will retain some of its features. For example, according to Eric Parry Architects founder Eric Parry One Undershaft retains the upper floors for educational and public access through a collaboration with the Museum of London.

Development and Construction

Developed by Aroland Holdings, One Undershaft is set to replace the St Helen’s tower that sits in the heart of the ‘Eastern Cluster’ of the City of London at the junction of St Mary Axe and Leadenhall Street. Construction is expected to take approximately five years subject to planning, with enabling works starting in 2024. The actual construction work will start in late 2025 after the demolition of St Helen’s tower and be completed 4 years later in 2029.