However, in some cases, a radical redevelopment and an increase in the area, which involves the movement of plumbing, the doorway beyond the approved limits of their placement, is required. In this case, additional waterproofing work, the transfer of sewer pipes and plums are required, which already requires a legal permit that takes into account the number of storeys of the house, the degree of wear, the placement of residential areas of neighboring apartments and many other factors.