West Lancashire council is preparing to publish a development tender for 9.6 acres close to Ormskirk town centre.
The site covers the former Atkinson & Kirby timber yard and council offices at 52 Derby Street. Atkinson & Kirby vacated the site in 2005.
The brief is being drawn up with architects Buttress Fuller Alsop Williams. An outline planning application is due to be submitted shortly.
The council wants to see around 100,000 sq ft of offices, and will partly occupy the space itself. Around 150 residential units, as well as supported residential, community facilities, public open space and light industrial are also envisaged.
John Ryding, the council's project manager, said detailed proposals were being worked up ahead of the formal tender, with further pre-application consultation due to be carried out. No timetable has been given.