Transport for London is to work with Pocket Living to build 125 affordable flats on various sites across London.
The one-bedroom flats will be prioritised for first-time buyers and people living or working in the same borough.
Pocket Living builds affordable housing without public subsidies, sold outright to buyers at local market discounts of at least 20%.
Any homes that are later sold on will also need to meet the buyer criteria, and require people to have a household income of less than the affordable housing threshold.
TfL director of commercial development Graeme Craig said: