Overruled regulations

I refer to your published article in November/December issue of Construction Manager regarding Air Tightness/Leakage Testing (‘Work to rules’, Regulations Special Report, p39). Although I am pleased that CM has finally addressed air leakage, I must point out one obvious mistake in your report.

The Building Regulations presently require a building to achieve a maximum leakage rate of 10m3 per hour per m2 of total envelope surface area (ie walls, roof and floor) and not just the floor area as reported. This allows substantially greater leakage than would otherwise be permitted.

For most buildings constructed to date (tested for Building Regulations), a result of 10 based on the floor area alone would be great and a result of 2 (B&Q’s ideal) practically impossible.