The oldest part of County Hall dates to the Lancashire Constabulary building of 1878 and the newest, the Christ Church Precinct, was constructed in 1976. The old Christ Church was purchased from the diocese of Blackburn when it was deemed no longer required for worship. Its distinctive two towers were then combined with a four-storey office block to form the new administrative precinct.

Linking the towers with the offices is the two-storey chapel and chairman's office with a magnificent open-plan staircase as its centrepiece, built in stone saved and re-dressed from the former Christ Church and lit by floor to roof window panels of coloured glass tiles. The doors to the towers have ornate cast bronze door handles depicting important aspects of modern Lancashire industry, and a colourful octagonal carpet in the Chairman's office depicts Lancashire's abundance of natural power sources.

Each of the 12 interior doors of the precinct has a wooden panel inlaid with transparent and opaque pigmented resin and solid materials such as bone, metal and hardwood, all substances chosen for their colour and texture. Each panel expresses the spirit of Lancashire, from its wildlife to its rich agricultural past, from fisheries and ports to the seaside resorts, by featuring one of the main rivers running through the region. From the natural beauty of the Leven running south from the Lake District to transport hubs like the Douglas and the Mersey. From the industrial heartlands of the many cotton mills along the Irwell to the modern aerospace industry of the Ribble Valley.