The project saw the extensive remodelling and extension of a 1970’s office building.
The sloping topography across the site was such that the principal entrance, off Britton Street, was actually located on level 3 of the building and the resulting layouts meant that the largest floor plate, level 2 was partially landlocked and suffered from both poor access and low levels of natural light. The upper floors, levels 4, 5 and 6 were fully glazed on every elevation and suffered from both excessive solar glare and extremes of overheating during the summer months.
The building was originally clad in an early example of steel curtain walling which had been poorly installed, lacked basic insulation levels and had undergone little maintenance. However, the building was designated as a building of local interest enjoying iconic status in the area, particularly for the combination of modernist design with a strong, all be it faded, red colour – listed in the Survey of London as being “Pompeian Red”.
The design solution sought to address the various shortcomings found on site head on, in a holistic and sustainable manner:
• The cladding failures and problems with solar gain were tackled by the installation of a completely new insulated cladding system with a new purpose made external shading system.
• The inter connectivity and day lighting issues experienced on the floors were addressed by the incorporation of a new entrance pavilion and atrium arrangement, incorporating a helical feature stair to encourage movement.
The large atrium was incorporated into the design of the entrance pavilion to allow natural light to reach the two lower levels of the building. In this way the sunlight can penetrate to the lowest levels, from which rises the new helical stair.
• The scheme now provides environmental performance levels suitable for a central London office development, through the extension of the chilled beam system, insulation upgrades and the incorporation of a solar shading system.
• In addition the construction of a New Entrance Pavilion and Atrium greatly improves the user and visitor experience.
• Public realm improvements within the vicinity of the site have sought to enhance the experience of the general public through a pallette of new finishes and new external lighting.
Detailed solar analysis determined the shading and insulation requirements to be provided by the new external bris-soliel, which has become the most significant visual motif of the new development and the cladding. The modelling also established where there would be a shortfall in cooling capacity, which enabled the design team to extend the base system as required.
The other significant technical achievement is the design of the entrance pavilion and atrium. In order to avoid unnecessary and complex structural alterations a decision was taken early in the design process to maintain the primary structure supporting the, then, public piazza. This resulted in an asymmetrical cruciform structural arrangement within the atrium void.
This in turn led to the development of a similarly asymmetrical column arrangement for the pavilion roof. A slender triple column system was designed, fabricated in mirror polished stainless steel, which gives the roof the appearance that it is floating.
The project sits adjacent to a small park, St Johns Gardens and a public desire line runs across the site, from Britton Street to the park and Farringdon Station beyond.
As part of the project scope all surfaces within the public realm were upgraded, including new external lighting. There is also a small residential development whose entrance lobby is accessed via this route. The project scope also included for the refurbishment of this lobby for and on behalf of the residents.
The arrival sequence was significantly altered through the incorporation of a new entrance pavilion. On arrival a visitor is welcomed with the rather unusual experience of being at the top of an atrium rather than at the bottom.
All internal working spaces now have direct access to natural light. The incorporation of the atrium has effectively removed what was a dead zone in an excessively deep, poorly lit floor plate. The new helical stair rising the height of the atrium visually and physically links all the lower spaces, where none existed previously.
One of the most talked about aspects of this development is the surprise people experience when they first encounter the building. This relates to the unexpected nature of finding such a boldly coloured modern building in the heart of historic Clerkenwell.
This appreciation of the building extends to the almost tactile nature of the new solar shading, which together with the tree canopy in the adjacent park produces changing shadow patterns across the facades.
The development seeks to be a good neighbour and extensive consultations took place with local residents who have universally praised the development and the improved the aspect it has given their homes. This was confirmed by the development receiving a “highly commended” certificate from the historic Islington Society.
The building unfolds to both visitors and users. The placing of the atrium adjacent to the public walkway allows for unexpected views into the heart of the development. The quality of light within this space makes using the helical stair a magical experience.