If you notice sudden building activity going on in a garden near you or an outbuilding that appears to be used day and night, inform the Planning Department or your local Councillor.
Building of a garden outbuilding can start without a planning application. Applications to the Planning Department for an outbuilding to be constructed within the confines of a rear garden are increasing. Frequently, the plans include running water, connection to the electricity supply and sewage. Some include two of the facilities and some none. They are described as a garage or a games room or a work room sometimes a business office.
But some unscrupulous applicants actually want to use it as a habitable permanent residence and use all sorts of subterfuge to cover up the real intention.
Planning and building regulations were brought in to ensure that properties were fit for purpose and safe to use, planning on its own is used to control the spread of buildings - to live and work in. To allow the spread of permanent living quarters in garden outbuildings destroys the reasons for planning and would lead to a developers' mandate. No control for where, or how high or how many.
If connected to a house, fine. But if they are separated by an existing "green space" it is detrimental to the neighbourhood and the local amenity irrespective of whether or not it meets the statutory requirements.