The Asticus building in St James is an office at 21 Palmer Street originally completed in 2006. The circular plan form cleverly enabled a tall building on a constrained site, and the building won a BCO National Commercial Workplace award in 2007. Over the last two years, we have taken the building through a natural cycle of refurbishment. The intervention is subtle, taking the beauty of the original design and refreshing the spaces with new amenities, welfare and reception so it is brought into line with how people need to use it today. But squint, check an old photo, and you may notice that we’ve also added a floor.

Using hydraulic lifting technology we severed the penultimate office floor and plant enclosure above, raised them one level, and then inserted a new floor. Temporary works were installed, then the columns were cut and the floorplates disconnected from the core. The lifting of the 400-tonne, two-storey load was carried out by four synchronised jacks over ten days. Once completed the new floor was constructed underneath using a bubble deck slab and the jacked floors were reconnected to the core structure. This form of construction is generally used in bridge or infrastructure engineering, but rarely in building construction. However, in this case, the benefit of maximising the retained structure reduced the additional embodied carbon of more traditional construction and avoided disruptive and noisy demolition and reconstruction. 

The existing bespoke curtain walling and shading on the top floors were retained and reused. Precast concrete cladding to the laterally extended 8th floor and the extended core was supplied by the original specialist subcontractor Decomo with the material and detail exactly matching the original.

Within the building, the reception design focused on a curving feature wall that leads towards the lifts. This was finished in an array of bronze-coloured angles with feature lighting to the head and base. This key intervention was punctuated by secondary timber elements, a recessed coffee niche, and a curvaceous cantilevered linear bench with bespoke leather cushions. Loose tables and a variety of seating allow the space to be used flexibly for waiting, meetings, or events. A portion of the ceiling was exposed with its curve and a radial array of suspended linear lighting accentuating the drama of the building’s curved form. Above, the Cat A renewal of all floors and upgrade from EPC E to EPC A complete works to all spaces within the building. 

And so the building slips calmly into its next cycle, a quiet intervention complete and sustained longevity continuing.