It depends on the size and type of extension. Bray comes under Wicklow County Council, not Dublin City Council, but the national exempted development rules still apply: a single-storey rear extension of up to 45 m² in total, leaving at least 25 m² of garden and no higher than the house, usually needs no planning application. If your home is on a terrace or is a protected structure near the town centre or the seafront, extra restrictions can apply. We go through this with you before any work starts, and a Section 5 declaration (€80) from the council confirms it in writing.