Sto revitalises London office building with specialist rendering

Sto, in partnership with applicators Chiltern Contracts, have delivered a rendering project maximising performance and aesthetics for a refurbished multi-purpose building in central London.

Located in Oxford Circus, Henry Wood House was constructed in the 1960s and comprises a 16-storey tower with two five-storey interconnecting wings. The building incorporates 69,000 sq ft of offices, 10,800 sq ft of retail and a hotel on the upper seven floors.

The external renovation required the existing façade to be refurbished including new rendering. 

Sto was selected to design a system which would not only repair the damaged façade but meet a specific design brief from Ben Adams Architects and building owners Derwent. A modern, linear render finish was needed to bring texture to the building render and provide a durable surface.

Bogdan Stefan, Project Manager for Chiltern Contracts’ facades division, said: “The linear appearance, which was to be applied across thousands of metres, was particularly challenging and hadn’t been replicated anywhere else in the UK before. 

“Meticulous planning was paramount to achieve the required result. Sto provided specialist training for our applicators so we could create extensive mock-ups for the client’s approval before commencing the work.”

To create the StoSignature linear appearance, Stolit MP render was applied and, using a special V-shaped trowel, the applicators carefully pulled the trowel in one direction across the render and at a specific angle to create the exact finish required. 

Bogdan continued: “Replicating the exact lines approved in the mock-up but on a much larger scale required significant skill and patience. To ensure consistency and the highest standards, the applicators who were specially trained by Sto completed the entire project from start to finish.”

Prior to applying the specialist render finish, the StoReno Plan system was used to repair the façade and was installed over the failing mosaic tile cladding and granite slips. The system comprised an adhesive bedding coat, StoReno A recycled glass, mesh-reinforced carrier boards, a reinforcing coat with reinforcing mesh (fully embedded) and the decorative render finish, which will ensure the new façade is resistant to cracking and weathering.  The new repair system is specifically selected for installations requiring A2-s1, d0 reaction to fire classification. 

The complexity of the installation saw Sto provide ongoing technical advice and support to the applicators throughout the project. Due to the building’s existing structure and high negative wind loads, strict fixing patterns had to be agreed and adhered to. The installation was reviewed by Sto at various stages to check the workmanship and to secure an extended warranty.

The rendering project was completed on time and meeting all parties’ high expectations.

All images (c)Jack Hobhouse.