David Holder suggested on your letters page (31 August, page 28) that a pass rate of 97.5% for Robust Details is not good enough – and that “nobody wants to talk about it”. That’s wrong. I do.

Compliance rates under the old Building Regulations were poor, with 25-40% of separating walls and floors failing to meet the performance standards. The target for Part E on sound resistance was to achieve 95% compliance within 10 years. The Robust Details scheme is far outperforming this target – by a factor of two – and we’ve achieved this within three years.

We do ourselves no favours, in a statistical sense, by focusing our testing on new and under-performing Robust Details. If we were to adjust our figures to allow for this, we’d return even more impressive results.

Any failures are reported to the building control body and are subject to normal procedures to ensure standards. What’s more, we can monitor performance and trends at a national level – something no other organisation can. Robust Details involves a feedback cycle, improving and upgrading patterns and even removing them from the handbook if they don’t perform.

So I am pleased to say that David’s question, “Can developers afford to trust the robustness of the detail?”, can be answered confidently in the affirmative.

Dave Baker, chief executive, Robust Details