Durkan will start work on the 354 home Britannia Music site in Ilford, now the Mayor of London has agreed a £25m loan to enable the project.
The plan will deliver 93 affordable flats, 206 privately-rented homes and 55 homes for sale, as well as 865 sq m of commercial space in buildings of up to 23 storeys.
Work should begin in autumn 2016 and complete by spring 2019.