You may be able to add several outbuildings under PD, but the total area covered by such buildings must not exceed 50% of the total area of the curtilage, accounting for any extensions, but not the area covered by the main house. Similarly, outbuildings cannot sit forward of the principal elevation, and there are height restrictions depending on the type of roof. Outbuildings cannot be used for residential accommodation, such as bedrooms or annexes, under permitted development, but they can be used as a home office.