The HBF do not consider that this paragraph on windfall's currently provides all sides of the story. There are many factors which could affect the level of windfall development, firstly the windfall level could have been set at an unrealistic level so was never going to be achieved. Secondly by their nature there is not an unlimited supply of windfall sites and no guarantee of when they will come forward so their availability is likely to reduce over time, both of these points should be included within the paragraph. Further if it is just down to small sites as explained in the paragraph it would help to provide some data to support this.