Here's Noel Larkin's answer to a readers question Published in Irish Times, Property Clinic Section, Dated 29th October 2015
Q My next-door neighbour is erecting a stand-alone structure ie, it is not attached to the side or rear of his house – of about 32.5sq m (350sq ft) and an external wall height of about 3.025m (10 ft). Can you please advise me what planning and building regulations should be adhered to?
A. When a neighbour starts to build in their garden, there is always a concern that this will have a negative impact on adjoining properties. The Planning and Development Acts generally allow limited exempted development. This means that it is not necessary to apply for planning permission for minor works around the house.
Due to their nature it is considered that these works would have no significant impact on neighbouring properties or the area in general.
However, once a development moves beyond certain limitations, planning permission is required. The type of development you describe is a Class 3 development. This allows the construction, erection or placing, within the garden of a house, a garage, store, shed or similar structure. However, in order for this structure to be exempted development, it should not be placed forward of the front wall of the house. The total area of the structure, when taken with other similar structures, which may have been previously constructed, should not exceed 25sq m.
The amount of open space, which should remain to the rear or side of the house, should not be reduced below 25sq m. The external finishes of the structure, should match the house. The height of the structure should not exceed 4m if finished with a pitched roof, or 3m if it has a flat roof.
The structure should not be used for human habitation or for keeping pigs, poultry, pigeons, ponies or horses or any other purpose, other than a purpose incidental to the enjoyment of the house.
You say you estimate the structure is about 32.5sq m. This is above the permitted exempt development and so planning permission is needed.
Structures which need planning permission, must also comply with building regulations.
If you are concerned that the proposed structure will have a negative impact on your property, discuss this with your neighbour.
Alternatively, you should contact the local authority planning department and they will pursue the matter on your behalf.