Edinburgh City Council last week approved the development, which will have space for 350 workers and include public meeting facilities and a cafe.
It is hoped that the scheme will kick-start the wider £250 million regeneration of the town centre, which is being overseen by council-owned joint venture PARC.
The scheme is set to include a supermarket and housing on the site of the old Niddrie Mill Primary School, both of which have attracted private sector interest.
A total of 3,000 homes are planned over 15 years, along with a secondary school, 28,000m2 of commercial and retail space and a network of public parks.
"The building of new council office accommodation in Craigmillar is an important milestone in the realisation of the council and PARC's vision for a vibrant town centre where people can live and work," declared the council's convener for economic development Tom Buchanan.
"We view this as a flagship development that will act not only as a signal of this council's ongoing commitment to regeneration in Craigmillar but also as a trigger to further private investment in the area," he added.
"Of course, in these difficult times, developments such as these will create welcome job opportunities in construction and other related areas." It is hoped that work will begin early next year with completion by mid 2012.