Persimmon and Barratt have weathered the market slowdown during 2006, reporting strong results for the year and half year ending December 31 respectively, while George Wimpey’s transatlantic Morrison Homes brand was hit by the US slump, which ate into the group’s yearly profit margins. Buoyed by its acquisition of Westbury in early 2006, Persimmon reported an “exceptional”performance. On an annual …