6 Development plan
Schedule 1 to the Act applies to–
(a) a structure plan and any alteration to or replacement of a structure plan to which article 2 or 3 applies and which is approved by the Scottish Ministers after the relevant date; and
(b) a local plan and any alteration to or replacement of a local plan to which article 4 or 5 applies and which is adopted by the planning authority or approved by the Scottish Ministers after the relevant date,
in the same way as it applies to an old development plan within the meaning of that Schedule as if such structure plan, local plan, alteration or replacement is in force as respects any area immediately before the relevant date.