A floating building work assembly including in combination: - a tank arranged in the ground, including side walls, a lip, and a bottom, containing water up to a free surface; - a closed-shell waterproof structure forming a floating ground, including a ground-floor upper subfloor and a bottom lower subfloor, and having its bottom and its side walls realized as a bilge interspace for the collection of seepage and condensation water; which closed-shell structure is floating in said water, and is suitable for forming a foundation for a building construction i.e. edifice i.e. building, this one being provided with building technical installations, including sanitary fixtures, supporting the building construction above said free surface by hydrostatic thrust in said water; wherein said floating ground is provided with floating level control hydrostatic cistern means, and with antirolling control float means; and including mechanical damper means between said ground-floor subfloor and said lip of said tank; wherein said mechanical damper means include pneumatic or oleodynamic telescopic arms, fed by an air or oil feed pumping circuit, and anchored to said lip of said tank, protruding from the lip itself towards the interior of the tank, forming decelerators, to constantly keep said floating ground centered in said tank and decelerate horizontal translations of the edifice towards the lip, so avoiding the danger of collisions with said lip of said tank, particularly in the event of a seism; wherein said floating ground is endowed with omphalus means (19, 19'), and waterproof home service supply hose means pass through said tank, coming from an underground passage conduit, suitable for supplying feeds to said technical installations and remove drains from said sanitary fixtures passing through said omphalus means (19, 19'); said omphalus means (19, 19') including a port for the opening of the bottom of said bottom subfloor and water seal caisson means, suitable for containing water entering from said tank through said port, said caisson means being raised, being upperly open, from said bottom subfloor about said port up to such a height as to always turn out to be higher than the water surface in said tank, whereat the water arranges itself too entering thereinto by the principle of communicating vessels; so always leaving a head air interspace (19") over the water surface in said caisson means; and including brim i.e. continuous perimetrical bridge modular means, overhanging from said ground-floor subfloor to said lip of said tank, with a slope descending towards the lip of the tank, anchored to said ground-floor subfloor and only resting on said lip of said tank, or as an alternative anchored to said lip of said tank and only resting on said ground-floor subfloor; and including a main control box including information storing, processing and transmission programmable means, in functional communication with accelerometer and anemometer means, and programmed for commanding said floating level and antirolling control means, and for commanding the immediate unloading of said feed circuit by simultaneously unloading all said telescopic arms in the event of detection of a seism. - a tank arranged in the ground, including side walls, a lip, and a bottom, containing water up to a free surface; - a closed-shell waterproof structure forming a floating ground, including a ground-floor upper subfloor and a bottom lower subfloor, and having its bottom and its side walls realized as a bilge interspace for the collection of seepage and condensation water; which closed-shell structure is floating in said water, and is suitable for forming a foundation for a building construction i.e. edifice i.e. building, this one being provided with building technical installations, including sanitary fixtures, supporting the building construction above said free surface by hydrostatic thrust in said water;