Recessed sinks are the easiest way to retrofit a washbasin. Depending on the substructure, you cut a plate to size (plastic or wood), saw in a corresponding cut-out and insert the recessed sink. Seal it and then you are done. The fittings find their place on the base plate. This way, you can retrofit any washbasin. These washbasins (except stainless steel) are made of 4 mm polystyrene base material. Even at the lowest and most sensitive point (at the drain), there is enough material to withstand the pressure of the drain.
With drain fitting, for installation in a worktop. Drain: 3/4"