Gasholders London, a residential development of 145 apartments, are the only apartments in the world to be built within a trio of listed gasholder frames. The development comprises of three circular residential blocks situated within three interlocking gasholder frames, affectionately called ‘The Triplet’. The 19th century ironwork frames were dismantled, restored and relocated within the King’s Cross development.
The project is an example of the innovative re-use of industrial structures which otherwise would remain unused. In a time of increasing urbanisation, such projects are essential to land conservation, and the reduction of urban sprawl.
Working with Argent (Kings Cross) Limited and Wilkinson Eyre Architects, we provided structural, civil, geotechnical, façade, wind and fire engineering advisory services.
40.5m height of the tallest gasholder frame
150+ year old gasholder frames
23,950m² luxury residential and retail space
The Gasholders are truly unique. I’m delighted that we contributed to yet another first, and the imaginative repurposing of such a treasured part of our Victorian heritage. ” Ed Clark Director, Building Engineering
The structural engineering challenge
The delivery of these high-spec residential units within a radial geometry presented a number of unique structural challenges, both in terms of the restoration of the Victorian gasholder guide frames, and the design of the new apartment buildings that are encircled by these heritage structures. To overcome these challenges, the team had to adopt an efficient yet flexible engineering approach. Our specialist skills were brought to bear in defining the strategy for restoring and repairing the cast and wrought iron guide frames - allowing them to stand independently of the new buildings. We also designed two slender steel bridges in the central courtyard. They weave through the Victorian ironwork and are supported as lightly as possible to create the maximum contrast between old and new.
As the apartments sit within the Victorian framework, the facade was developed to respect the constraints of the original structure yet open up to create well day-lit internal and external living spaces.
The gasholder frames prevented more traditional methods of installation due to the restricted access. We introduced a unitised system that would still ensure a high-quality façade, yet enable an efficient and agile construction method. The façade could be installed from the floor slab whilst the gasholder framework was rebuilt and other façade features, such as prefabricated shutters and balconies, could then be hoisted into place.
A key feature of Gasholders London are the motorised sliding, folding shutters for which residents have individual control, as can be seen above. At 4m high, the shutters are unusually tall and with four panels each operating concurrently around a faceted curve, they presented a challenge. Their reliability and operation was paramount to the façade’s success so we defined a full test programme which included life-cycling of the system, impact and simulated wind loads. This gave everyone confidence that the shutters could withstand even gale force winds in any open position.