Going up! Creating building space where there is none!
As Westminster launched a consultation last week on tall buildings stating clearly that it was ‘not about sky scrapers’, the controversy was already beginning. The Evening Standard’s lead story was headlined ‘Skyscrapers in Westminster?’ and the article claimed that ‘A new crop of towers could be on the way in’.
The objective of the consultation is to seek the views of all those who live, work and visit the city about the right kind of development to cope with a growing need for housing and office space. A challenge all over London, this is particularly so in Westminster because the Palace of Westminster is a world heritage site and new structures must not impede sightlines to it or St Paul’s Cathedral.
But upward growth is not a new phenomenon, even in Westminster, and it does not need to be controversial or visually detrimental. The potential commercial benefits for property owners, developers, businesses wishing to operate in the city and the city itself, even when only a couple of floors are added, could be substantial.
Clarkebond have a long track record in helping clients to maximise floor space on existing and historic building stock and understand the structural challenges involved and how to overcome them. Clarkebond’s in-house expertise on construction over underground structures has also been particularly useful in these areas.
A recent Clarkebond project involved the conversion and extension of five former office buildings on Canon Street, opposite the Mansion House underground station, overlooked by St Paul’s Cathedral and located in a Conservation Area.
The five former office buildings were a combination of early Victorian and modern construction with differing construction styles, materials and roof lines. An added complexity was that a public house situated between two of the buildings and the ground floors across two of the buildings were in separate ownership and had to be worked around. There was no room for a tower crane, so everything had to be designed to be lifted in small sections. The location also presented challenges for deliveries to site and pumping concrete.
The scheme, comprising 77 studios and one bedroom serviced apartment suites arranged over six storeys, was primarily a refurbishment project although some new build elements were incorporated. These included the construction of a five storey link building and adding an additional storey on two of the Victorian buildings. The old roofs were removed and replaced with a linked mansard roof design.
In addition to the extensive reconfiguring of internal walls and floor plates and retrofitting lift shafts, there were two other significant structural aspects to be managed. Firstly, the back of the one of the buildings had had to be removed in order to allow the required reconfiguration. This required major temporary/permanent works and had to be carefully sequenced to maintain the integrity of the building. The second was the need to retrofit structural members to the historic buildings to comply with modern disproportionate collapse requirements. More
So, the challenges are known, the rewards could be substantial and even before the results of the consultation are known, there is scope for upward development.
We look forward to learning the outcome of the consultation and we will be ready if it results in a relaxation of planning restrictions on the vertical extension of West End’s historic commercial buildings.