Building an arch in the busy centre of London is never likely to be easy. Unless you use GRC. This arch near what was the Childrens Hospital in St. Georges Mews was erected on a steel frame off site and craned into position in 1/2 a day. The side pillars were built in engineering brick and rendered to match the GRC unit which was located and bolted into the top of the piers. Another example of the benefit of reduced weight and off site prefabrication.