20 Cannon Street
With spectacular views overlooking St Pauls Cathedral and the City of London, this state-of-the-art six-storey building provides nearly 40,000 sqft of prime office space, on a prominent island location.
Allied London Properties
Architect
Denton Corker Marshall
Contractor
McLaren Construction
Quantity Surveyor
DBK Group
Working with our partners McLaren Construction, we undertook the design, manufacture and installation of the whole external envelope. The façade was the key package in the refurbishment of this building, stripping it back to its original 1960’s shell and core, and re-cladding with floor to ceiling triple glazed unitised curtain walling, that spanned the 3m structural bays.
Working with the existing concrete frame which was a hollow-pot slab posed structural challenges both in the design of the new cladding but also limitations in the installation strategy. As an island site with the building filling the footprint, the location and existing building frame meant no craneage was available, so a design was worked that would utilise the new BMU at roof level for installing the large unitised panels.
To meet the buildings performance criteria, high specification, low-iron, triple glazing was used with the south facing façade including interstitial copper mesh. Other areas included a structural parapet formed at roof level, to hide the plant and a new main entrance with structural glazing and revolving doors. Architectural cladding and metalwork was also included in our package including soffits, fascias, balustrades and copings.
Prior to practical completion the offices were already pre-let to a leading international consultancy firm. This meant the client’s aspiration to complete this project within the challenging programme and deliver the appearance of a newly constructed office building were paramount and we successfully achieved this. The floor to ceiling glazed units increase natural light into the building and achieve Part L compliance through the triple glazed elements, in addition to being awarded BREEAM ‘Excellent’ and EPC ‘B’ rating.
