Barratt Developments has enjoyed a “strong” half year, with pre-tax profit up but total completions slipping. During the six months to December 31 2016, the volume housebuilder’s pre-tax profit rose 8.8% to £321 million against the equivalent period the previous year. Meanwhile, revenue dipped 3.2% to £1,816.2 million. Barratt said that its completions outside London had reached their highest level …