More than 2,000 Birmingham City Council staff are set to move to new environmentally friendly offices on Aston Science Park.
Cabinet members backed proposals for a 180,000 sq ft building between Woodcock Street and Holt Street.
The project is the latest stage in the central administrative buildings rationalisation, which aims to replace more than 20 rented buildings with a handful of purpose built offices.
The programme will leave the authority a stock of modern, green and efficient buildings, saving £100 million over 25 years.
But the prospective move sparked a row about the suitability of the science park. Opposition Labour group leader Sir Albert Bore, a science park director, said the building could “ruin the whole ethos of Aston”.