Trapped, as Lambeth changes its planning rules overnight

Our L-shaped dormer was allowed under permitted developments. Then, when work began, it wasn’tWe started work on a loft conversion in May last year. The standard L-shaped dormer came under permitted development rights which do not require planning permission. But when the work began we applied for an optional certificate of lawfulness from Lambeth council. It didn’t review our application until September when it was rejected. It turned out that the planning department had unilaterall