The grants are for the construction, lower cost at the front end means the rents aren't as high.I saw a housing estate just outside Glasgow where a small construction company had built 15 houses for sale but covid had killed the sales so they have turned the into rental properties and are using the same formula as the local authorities for rental costs, the rent is a more expensive than the local authorities but they are considering going completely rental as they still have the properties as collateral to enable them to build more properties for rent.
Most private landlords buy existing properties but this approach is quite unusual and forced upon them to a certain extent but the regular income via rent was the deciding factor.