When it is mandatory to build a surface or a floor plate over subsiding foundations, this major constrain can be solved using a network of piles at reduced depth on which to lay the surface thanks to the so-called AD-Slab system. Such system is absolutely unique and designed to allow depth adjustment of the concrete slabs, only if post-tensioned.Through a regulation mechanism, the system allows to to compensate any subsidence which might happen through the time, using a millimetric device incorporated into the foundation plate. With a leverage over the different piles of the structure it is possible to reinstate surface planarity without obbligation to use expansion resin injections, or without partial demolition of the surface itself.