Kirkwells, based in Burnley, officially began business this month and comprises four chartered town planners, an environmental specialist and a regeneration finance expert.
The practice will provide services to private, public and community clients and initially operate across the north and Midlands.
The six decided to set up the practice last December when they were put at risk of redundancy. They have all subsequently been made redundant by the council.
Director Michael Wellock said: "We were not prepared to wait around for something to turn up or someone to create a job for us. There is a lot of competition and it's probably not the best time to set up a business, but we have a realistic business plan. We're looking forward to working with private sector on the Government's growth and localism agenda."