It is expected to deliver around 119,000 houses in England, with around half expected to be sold and tens of thousands built to rent at a discounted rate.
The funding forms part of the £11.5billion affordable homes programme which runs from 2021 to 2026 and could provide up to 180,000 houses.
The £8.6billion investment will deliver properties including 57,000 homes for ownership, 29,600 for social rent, typically around 50 percent to 60 percent of market rates, and 6,250 affordable rural residences.
The remaining homes will be available for "affordable" rent, say officials. Housing Secretary Robert Jenrick said: "Creating more opportunities for home ownership is central to this Government.
"This £9billion funding is a landmark moment for our affordable homes programme and will ensure good quality housing for all as we build back better.
"This huge funding package will make the ambition of owning a home a reality for families by making it realistic and affordable.