6U.K.The owner or occupier of, or of any part of, a building which is not within the City of Cardiff, the Community of Penarth or the Community of Llandough may at any time during the period beginning with, and ending twenty years after, the commencement of impoundment when he is able to show a justifiable concern that the building has suffered or is likely to suffer groundwater damage require the Development Corporation to arrange a survey of the building.