We envisage that the Water Calculator will be completed initially when fittings and appliances are specified during the design stage and then revised if those fittings subsequently change. However, the provision does not require this, simply that a notice is given to the building control body within five days of the completion of work (or, where the building control body is an approved inspector, not later than the date on which the initial notice ceases to be in force under regulation of the Building (Approved Inspectors etc) Regulations 2010 if that is earlier). The regulations require only that the notice states the potential consumption, however, we envisage that, in practice, a copy of the completed calculation table will be submitted to the building control body.