A closure assembly with a window comprising: front and rear panels (101, 102) defining a space therebetween; an aperture (101A, 101B, 102A, 102B) in each of the front and rear panels (101, 102), the apertures (101A, 101B, 102A, 102B) being aligned to form an aperture 105A, 105B) for the window; a frame at least partly positioned between the front and rear panels and extending along the apertures to delineate the space and define a cavity between the front and rear panels (101, 102); and filling material placed in the cavity and bonding the front and rear panels (101, 102) together thereby forming a one-piece structure; wherein the frame includes an inner frame sandwiched between the front and rear panels (101, 102) and a holder extending into the aperture (105A, 105B) for the window and running substantially parallel to the panels (101, 102) for holding a piece of glass for the window; and the holder includes a first holding member that extends therefrom into the aperture (105A, 105B) for the window, and a second holding member co-operable with the first holding member for holding the piece of glass for the window; characterised in that: the first holding member is integrally formed with the inner frame to form an integrated frame; the second holding member is snap-fitted laterally on to the first holding member such that the second holding member is releasably retained on the frame by a releasable retainer for fixing relative position between the first and second holding members (110A, 110B); and the integrated frame prevents the filling material from entering the space with and between the apertures (101A, 101B, 102A, 102B) and provides rigidity to the aperture for the window. front and rear panels (101, 102) defining a space therebetween; an aperture (101A, 101B, 102A, 102B) in each of the front and rear panels (101, 102), the apertures (101A, 101B, 102A, 102B) being aligned to form an aperture 105A, 105B) for the window; a frame at least partly positioned between the front and rear panels and extending along the apertures to delineate the space and define a cavity between the front and rear panels (101, 102); and filling material placed in the cavity and bonding the front and rear panels (101, 102) together thereby forming a one-piece structure; wherein the frame includes an inner frame sandwiched between the front and rear panels (101, 102) and a holder extending into the aperture (105A, 105B) for the window and running substantially parallel to the panels (101, 102) for holding a piece of glass for the window; and the holder includes a first holding member that extends therefrom into the aperture (105A, 105B) for the window, and a second holding member co-operable with the first holding member for holding the piece of glass for the window; characterised in that: the first holding member is integrally formed with the inner frame to form an integrated frame; the second holding member is snap-fitted laterally on to the first holding member such that the second holding member is releasably retained on the frame by a releasable retainer for fixing relative position between the first and second holding members (110A, 110B); and the integrated frame prevents the filling material from entering the space with and between the apertures (101A, 101B, 102A, 102B) and provides rigidity to the aperture for the window. the first holding member is integrally formed with the inner frame to form an integrated frame; the second holding member is snap-fitted laterally on to the first holding member such that the second holding member is releasably retained on the frame by a releasable retainer for fixing relative position between the first and second holding members (110A, 110B); and the integrated frame prevents the filling material from entering the space with and between the apertures (101A, 101B, 102A, 102B) and provides rigidity to the aperture for the window.