The Old War Office is a Grade II* listed building with a rich and unique history. Completed in 1906, the building was once used by Prime Minister Winston Churchill and sits at the heart of Whitehall. The 760,000 sq ft development will bring the Old War Office back into use, creating a world class 5-star hotel and 85 apartments. Works will include developing a six storey basement and constructing a three storey roof extension. The venue has been designed by UK-based EPR Architects, with the hotel interiors designed by New York-based designer Thierry Despont, and the residences by 1508 London.

Effisus Breather FR Class A1 membrane was used to protect the building façade elements from driving rain and moisture preventing future corrosion, insulation deterioration and mould growth at the same time it increases the building energy efficiency and minimizes the condensation risk. 

Effisus Vapour FR Class A1 membrane was used to prevent the condensation risk, improving the airtightness and consequently the energy efficiency of the building.