Frame consisting of a casing comprising first perimeter elements (8, 10, 11) obtained from first elongated section bar components and constituted of at least one wing comprising second perimeter elements (20, 16, 15) obtained from second elongated section bar components, said casing being adapted to be inserted within an opening obtained on a wall or on a roof of a building, said at least one wing being selectively openable and lockable on said first perimeter elements (8, 10, 11) of said casing, in which said first perimeter elements (8, 10, 11) of said casing include at least two section bars, having identical section to the section of two corresponding section bars of said second perimeter elements (20, 16, 15) of said at least one wing, in which said frame includes at least one connecting element of the casing and at least one connecting element of said at least one wing, said connecting element (10, 16) including a first insertion site essentially "C" shaped which is delimited by two arms, said first insertion site being adapted for inserting insertion blocks obtained on internal coverings (12, 17) in which said second perimeter elements (20, 16, 15) include at least one elongated section bar component constituting an insulating element of the at least one wing, the connecting element of the casing being an elongated section bar component and said connecting element of said at least one wing being an elongated section bar component, the elongated section bar constituting said connecting element of the casing being the same as the elongated section bar constituting said connecting element of said at least one wing, in a sense that said elongated section bars are identical in section being them formed from the same section bars, constituting a connecting element (10, 16) that is an element obtained from a section shared by said casing and said at least one wing, the first elongated section bar components being formed from said first perimeter elements (8, 10, 11) of said casing including at least one elongated section bar component constituting an insulating element of the casing and said second elongated section bar components being formed from said second perimeter elements (20, 16, 15) of said at least one wing include at least said elongated section bar component constituting said insulating element of the at least one wing, the elongated section bars constituting said insulating element of the casing being equal to the elongated section bars constituting said insulating element of the at least one wing, in a sense that said elongated section bars are identical in section being them derived from the same section bar, constituting an insulating element (8,20) that is an element obtained from a section shared by said casing and said at least one wing, and further in which said at least one wing includes a glass or panel applied on said at least one wing, said glass or panel being fixed on said at least one wing by means of a glazing bead element) by interposing a protection gasket, said glazing bead element being fixed on said insulating element of the wing by means of screws, said panel or glass being inserted within a hollow peripherally defined inside the frame of the wing from a surface of the insulating element of the wing and being locked in position by said glazing bead element, said internal coverings (12, 17) forming finishing elements of an internal side of said frame, internal being referred with respect to the building on which said frame is mounted, with internal meaning the side of the frame facing the interior, the fixing of said internal coverings (12, 17) being performed by means of coupling notches on said arms, said coupling notches engaging on a surface coupling said insertion blocks of said internal coverings (12, 17), said surface connecting said insertion blocks being an essentially smooth coupling surface and with no coupling recesses with said coupling notches achieving an easily releasable coupling interface, said internal coverings (12, 17) constituting easy to be interchanged finishing elements in a sense that the mutual fixing between said internal coverings (12,17) and the first insertion site allows a fast removal of said internal coverings (12,17) for their replacement and/or maintenance wherein fixing of said internal coverings (12, 17) within said first insertion site essentially "C" shaped is performed by interposing a fixing means (11, 15), the fixing of said fixing means (11, 15) within said first insertion site being performed by means of said coupling notches on said arms, said fixing means (11, 15) constituting a coupling interface between said connecting element (10, 16) and said internal coverings (12, 17).