Take this room if the address does more work for you than the floorplate. 4 Hill Street is a period townhouse at the Berkeley Square end of a street laid out in the 1740s, and this is the middle room on the ground floor: tall ceilings, the original proportions, furnished and open-plan. A staffed reception signs your visitors in and the building is open to you around the clock. Green Park is about seven minutes on foot, Mount Street Gardens three. Right for a firm whose clients walk in off the street and expect the address to match the conversation.