Private housebuilding stuttered in the three months to July, with the value of projects starting on site down to £1.4bn from £2.5bn in the previous three months, according to industry analyst Glenigan.

Some 1,950 projects started during the period, compared to 2,450 in the previous period.

Glenigan economist James Abraham said the dip highlighted the fragility of the recovery.

“The weakening in new project starts over the last three months points to an easing in construction output growth during the second half of this year,” he said.

But he said the decline in starts was not expected to continue to the end of 2010, when a mild recovery was anticipated.

New social housing starts have particularly suffered, with a 40% decline during the period compared to a year earlier. Glenigan said the social housing sector was not expected to recover within the next two years.

As a result, the Glenigan Residential Index for July, which tracks projects with a value between £250,000 and £100m, is 22% down on a year ago.