The number of new social housing property approvals has dropped by 41%, a new report reveals.There were 3,200 approvals in this year's second quarter - unchanged on the same period last year - but 41% down on 2012's first quarter.The data, compiled by Glenigan for the Home Builders Federation (HBF), shows that planning permissions across the board have slumped to a three year low.There were fewer than 25,000 approvals in the second quarter, well under half the 60,000 needed per quarter to meet hous...