Belfast·SPG004 Residential Extensions and Alterations·Page 38·4.3.14
Reduced separation distances for single storey extensions with boundary treatments
Single storey extensions may accept smaller separation distances where overlooking problems are overcome by suitable boundary treatments, which must be detailed and maintained as part of the development.
In the case of single storey extensions, a smaller separation distance may be acceptable where problems of overlooking can be overcome using suitable boundary treatments. Where this provides a design solution, details of boundaries and screening must be completed and maintained as part of the development.
Source — /Users/richardhill/Documents/planning-arch-project/data/documents/belfast/SPG004 Residential Extensions and Alterations.pdf