Fraser Bond are the leading lettings and property management agents for One Berkeley Street - London W1J. One Berkeley Street is a mixed-use development on Piccadilly in Mayfair, London W1. The 260,000 sq ft development will comprise a hotel, apartments, office and retail premises. 184-bed "1 Hotel London Mayfair", 60,000 sq ft of offices and 20,000 sq ft prime retail space. Architects Allford Hall Monaghan Morris and specialist hotel architect Dexter Moren Associates. 1 Hotel London Mayfair 1 Hotel London's design will be nature-inspired, bringing the outdoors in. The 9-storey hotel will house 184.