Two sample schools will be remodelled and extended through the BSF scheme,: The Sydney Russell School, and Dagenham Park Church of England School.
Each rebuilt school will feature additional facilities such as sport halls, libraries and ICT resources for community use.
The procurement phase of the project was relatively short for BSF at just 15 months from publication of the Official Journal of European Union notice to financial close.
Andrew Shepherd, Laing O'Rourke's project director, said: "As one of the country's leading constructors in the public sector environment, we are tremendously proud and excited to have reached Financial Close on this transformational educational programme.
“We have built an excellent relationship with the Council, which we are committed to building on for the future long term benefits of the communities within Barking and Dagenham."