There's two separate developments - 'The Park' which was built on an area of land on Robsart Street which was empty for some time (can't remember what was there before, I think it was some of the older bits of the Stockwell Park Estate,
boohoo might remember) - and Redmayne House (which is on the corner of Stockwell Park Road & Sidney Road, opposite the Grosvenor pub) which was demolished recently and is currently being rebuilt as 'luxury' apartments.
The Park is mostly private iirc with small amount of 'affordable' housing - i.e. part buy, part rent for people with incomes of £60k/£70k+. A quick search reveals two bed flats go for more than half a million quid!
Redmayne House was only about 20 flats as far as I remember, plus unused commercial units on the ground floor....and was kept half empty for the past 10 years or so in preparation for
this mundane new development of 30+ flats currently being built. The council received an unprecedented number of planning objections from the well-heeled residents of Stockwell Park (
hundreds, iirc) objecting to the height and proximity of the new development, loss of light & privacy to gardens etc, but it still went through. So same old story basically!
edited to add: 328 of the 368 dwellings in 'The Park' were for private sale. It was on the site of old sheltered housing
Old thread here from 2006:
http://www.urban75.net/forums/threads/new-tower-blocks-for-stockwell-park.97626/