PPG3 has been superseded by PPS3, however there were no percentages for affordable housing set out in PPG3.
PPS3 asks local authorities to set a target for the amount of affordable housing to be provided in their local development documents, based on an understanding of the needs of the area. PPS3 gives a national indicative site size threshold of 15 dwellings to which the policy should apply, although local planning authorities can set lower minimum thresholds where viable and practicable.