BAA's own blurb claims 15000m3 of concrete poured per week at the peak of T5 construction so using WHBM's figure of 600,000m3 that's 40 weeks for a runway, which sounds far more reasonable than 9 years. Perhaps the time scale includes 3 years of planning enquiry,3 years of deciding what shape and colour it should be and 3 years of doing nothing at all just to be on the safe side.