Howth falls under Fingal County Council, and the exempted development rules follow the national ones: 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, often doesn't need a planning application. However, Howth has a higher than average number of protected structures, particularly on Thormanby Road, Carrickbrack Road and around the village, and the hillside has landscape conservation designations. If your home falls into any of these, different rules apply. We check the position for your property at the quoting stage.