A composite structure usable in construction, for defining a delimiting wall of a corresponding habitable room of a building, wherein: - the composite structure comprises insulation means (10, 10) having a variable heat transfer coefficient; - the insulation means comprise first and second insulating means (10, 10) having a respective variable heat transfer coefficient; - the first and second respective insulating means (10, 10) have a heat transfer coefficient that is variable on command; - the first and second respective insulating means (10, 10) have a heat transfer coefficient that is variable as a function of the temperature of the outside environment (e) external of the habitable room (i) and/or as a function of the inside temperature of said room, in particular habitable; - the first and second respective insulating means (10, 10) are configurable in a first operating condition, in which they have a first heat transfer coefficient, and in a second operating condition, in which they have a second heat transfer coefficient; - the first and second respective insulating means (10, 10) are configurable in a first operating condition, in which they have a minimum heat transfer coefficient, and in a second operating condition, in which they have a maximum heat transfer coefficient; - the structure comprises corresponding infill means, or panel, in particular having a decorative purpose; - each of the first and second insulating means is an insulation panel; - each insulation panel comprises a containing body of a fluid, which containing body is configurable in a plurality of corresponding filling conditions defining respective conditions having a different heat transfer coefficient; characterized in that: - the structure comprises storage means of heat energy, i.e. defining a thermal mass; - said storage means of heat energy are provided at said insulation means, in particular aligned to the insulation means according to the main heat energy direction; - the storage means of heat energy are arranged between said first and second heat insulation means (10, 10); - said storage means of heat energy are arranged in contact with said first and/or said second heat insulation means (10, 10); - the storage means of heat energy are in the form of a body or panel made of a material able to store heat energy; - the respective heat transfer coefficients of the first insulating means and of the second insulating means are variable independently of one another; - the structure is able to define, on command, forced directional transmission means of the heat energy from inside the room towards the outside environment, or from outside environment towards the inside of the room. - the composite structure comprises insulation means (10, 10) having a variable heat transfer coefficient; - the insulation means comprise first and second insulating means (10, 10) having a respective variable heat transfer coefficient; - the first and second respective insulating means (10, 10) have a heat transfer coefficient that is variable on command; - the first and second respective insulating means (10, 10) have a heat transfer coefficient that is variable as a function of the temperature of the outside environment (e) external of the habitable room (i) and/or as a function of the inside temperature of said room, in particular habitable; - the first and second respective insulating means (10, 10) are configurable in a first operating condition, in which they have a first heat transfer coefficient, and in a second operating condition, in which they have a second heat transfer coefficient; - the first and second respective insulating means (10, 10) are configurable in a first operating condition, in which they have a minimum heat transfer coefficient, and in a second operating condition, in which they have a maximum heat transfer coefficient; - the structure comprises corresponding infill means, or panel, in particular having a decorative purpose; - each of the first and second insulating means is an insulation panel; - each insulation panel comprises a containing body of a fluid, which containing body is configurable in a plurality of corresponding filling conditions defining respective conditions having a different heat transfer coefficient; - the structure comprises storage means of heat energy, i.e. defining a thermal mass; - said storage means of heat energy are provided at said insulation means, in particular aligned to the insulation means according to the main heat energy direction; - the storage means of heat energy are arranged between said first and second heat insulation means (10, 10); - said storage means of heat energy are arranged in contact with said first and/or said second heat insulation means (10, 10); - the storage means of heat energy are in the form of a body or panel made of a material able to store heat energy; - the respective heat transfer coefficients of the first insulating means and of the second insulating means are variable independently of one another; - the structure is able to define, on command, forced directional transmission means of the heat energy from inside the room towards the outside environment, or from outside environment towards the inside of the room.