The sanctioned plan will have some space technically called as setback on all four sides of the building. In general it varies from 1.5m to 4m according to various development control rules. If the building is constructed leaving lesser setback than the one mentioned in the sanctioned floor plan , then it is called deviation. Also constructing more than the sanctioned floors is also a deviation. In some cases the number of dwelling units will be more than the sanctioned plan which also is a deviation. Purchase of flats having deviation in any respect is not advisable.