Device for fastening a glazed system to a load-bearing structure, said system comprising at least two glazed elements, an outer glazed element and an inner glazed element, separated from one another by a gas cell, the tightness of which is ensured by a peripheral spacer and by a tightness ring, the gas being a noble gas, a mixture of noble gases or mixture of air and noble gas(es) in which the proportion of the latter is greater than 85%, said device comprising a set of fastening elements, each comprising a rigid rod one end of which is associated with non-swivelling means of clamping onto the glazed system, which comprise: - a facade block configured to pass right through the inner glazed element through a bore and configured to be engaged in a bore of the outer glazed element, said facade block comprising, towards the outside, a widened head configured to bear against a correspondingly shaped bearing surface of said bore of the outer glazed element, and a threaded body associated with a swivel joint system which is configured to be connected to the load-bearing structure, and - said tightness ring, made of polymer material, configured to be engaged, without direct contact, around said facade block, characterized in that: - the facade block is made of a composite polymer material capable of fastening the glazed system to the bearing surface comprising a base polymer and a content of organic fillers, inorganic fillers or a mixture thereof of between 0% and 65% by weight, relative to the total weight of the polymer material, the composite polymer material having a tensile strength of at least 95 MPa in accordance with the standard ISO 527-2/1B/50, at 23°C, a Young's modulus having a value of at least 3.5 GPa in accordance with the standard ISO 527 and a linear thermal conductivity coefficient of at most 0.5 W/m.K, and in that - the tightness ring is at least partially covered on its surface with a metallic thin layer. - a facade block configured to pass right through the inner glazed element through a bore and configured to be engaged in a bore of the outer glazed element, said facade block comprising, towards the outside, a widened head configured to bear against a correspondingly shaped bearing surface of said bore of the outer glazed element, and a threaded body associated with a swivel joint system which is configured to be connected to the load-bearing structure, - said tightness ring, made of polymer material, configured to be engaged, without direct contact, around said facade block, - the facade block is made of a composite polymer material capable of fastening the glazed system to the bearing surface comprising a base polymer and a content of organic fillers, inorganic fillers or a mixture thereof of between 0% and 65% by weight, relative to the total weight of the polymer material, the composite polymer material having a tensile strength of at least 95 MPa in accordance with the standard ISO 527-2/1B/50, at 23°C, a Young's modulus having a value of at least 3.5 GPa in accordance with the standard ISO 527 and a linear thermal conductivity coefficient of at most 0.5 W/m.K, - the tightness ring is at least partially covered on its surface with a metallic thin layer.