If retention permission is refused, the development remains unauthorised and the local authority can pursue enforcement action, which may ultimately require the works to be altered, removed, or demolished. You can appeal a retention refusal to An Bord Pleanála (An Coimisiún Pleanála), or consider whether a revised, scaled-back application might succeed instead.
A refusal of retention permission means the local authority has decided the existing, unauthorised works are not acceptable in planning terms, so the development's status as unauthorised continues. This leaves the local authority free to pursue or continue enforcement action, which can include a formal enforcement notice requiring removal or alteration of the works within a specified period, and ultimately court proceedings if that notice is ignored.
The applicant has the same appeal rights as with any planning refusal, meaning a retention refusal can be appealed to An Bord Pleanála (now operating as An Coimisiún Pleanála) within the standard statutory appeal period, and the board will reassess the application afresh. If the appeal is also refused, or if no appeal is lodged, the refusal stands and enforcement risk resumes or increases.
In some cases it may be worth considering a fresh retention application with a revised, reduced, or modified proposal that addresses the reasons for refusal, particularly if the objections related to a specific element such as height, overlooking, or a boundary issue that could be resolved by amending the structure rather than removing it entirely. This does not guarantee success, since the local authority may take the same view again, but it is often a more constructive route than doing nothing.