Exception 1: single-property systems Exception 1: single-property systems Changes not yet applied. Later legislation changes this provision in ways not yet written into the text below: Sch. 3 para. 12(4)(c) words inserted by Water Act 2014 s. 88(a) Sch. 3 para. 12(4)(c) words substituted by Water Act 2014 s. 88(b) Sch. 3 para. 8(4) words inserted by Planning (Consequential Provisions) (Wales) Act 2026 Sch. 2 para. 406(a) Sch. 3 para. 14(4) words inserted by Planning (Consequential Provisions) (Wales) Act 2026 Sch. 2 para. 406(b) 18Paragraph 18 Exception 1: single-property systems