Homes England has agreed three funding packages worth £300m to deliver 20,000 homes across the capital.
The loan funding from the government's housing agency will accelerate construction in Brent Cross, Silvertown and Barking Riverside.
The funding will enable the schemes to invest in necessary infrastructure to speed up the construction of thousands of new homes.
Gordon More, chief investments officer at Homes England, said: 'By investing in projects on this scale and allowing funding to be recycled into future phases of development, we are able to support significant schemes where commercial lenders may not.
'This means these three major developments can invest in the infrastructure they need to deliver in these uncertain times and accelerate the delivery of new homes.'
In Brent Cross, £148m will fund the land and infrastructure works needed to unlock the delivery of 6,700 homes.
At Silvertown Quays, a £105m debt facility to unlock a minimum of 3,000 new homes.
At Barking Riverside, a funding package worth £56m will deliver upfront infrastructure at Barking Riverside, a 179-hectare development of over 10,000 new homes.