Justification and Amplification - Design Standards and Impact Assessment

The Department wishes to encourage the highest standard of design for all development, including proposals for residential extensions and alterations. Good design will help promote sustainable development and improve the quality of the existing environment. It should also afford appropriate protection of residential amenity. A proposal to extend or alter a residential property can have a significant impact on the character and appearance of the local environment. The main causes of harm arise where an extension is poorly designed, over-sized or badly sited or where inappropriate alterations are proposed. Even small-scale changes can, by virtue of their cumulative impact over a period of time, significantly erode the character of a street, village or rural setting. An extension or alteration can also affect the privacy and amenities enjoyed by neighbouring households, with issues such as dominance, privacy and loss of light often arising. Applications for house extensions and alterations therefore raise detailed, site specific issues and each case will be assessed on its individual merits. The acceptability of proposals will depend on the particular circumstances on the site and its surroundings and decisions will be informed by the guidance provided in Annex A.