<p>Persimmon has opened 105 new housing developments in the second half of the year to date and expects to open 20 more by the end of the year as the firm looks to continue to grow.</p> <p>In a trading statement today, Persimmon said the level of customer interest in its sites is "encouraging" with visitor numbers 5% ahead of last year. Mortgage approval volumes for customers are also up, with September approvals 13% ahead of last year.</p> <p>The group says it is driving to capture productivity improvements with its Space4 insulated panel manufacturing facility generating increased efficiency gains.</p> <p>Land availability is improving thanks to the National Planning Policy Framework with local plans "identifying sustainable locations for residential developments in increasing numbers".</p> <p>Persimmon says its operating margin continues to move forward and expects to improve on the 20.5% achieved in the first six months of the year.</p>