A side wall for a rail vehicle body comprising: an outer skin, a structural layer and a finishing layer adjacent an inner face of said structural layer, said side wall further comprising an insulating layer adjacent an inner face of said outer skin, said insulating layer being operative to provide at least one of a thermal and an acoustical insulation; wherein said structural layer is adjacent an inner face of said insulating layer, said structural layer having: a longitudinally aligned top door frame member; vertically aligned left and right door frame members each depending from a different end of said top door frame member, thereby defining a door opening; a longitudinal top structural member proximate said top door frame member; and a plurality of diagonal structural members oriented at an angle comprised between 1 degree and 89 degrees from said top door frame member, said plurality of diagonal structural members defining a lattice structure having a plurality of openings there in between, at least one of said plurality of diagonal structural members being connected to said longitudinal top structural member and defining a wiring channel for routing electrical wiring, said wiring channel extending downwardly and diagonally from said top structural member to an intermediate position between said top structural member and a bottom portion of said structural layer, said wiring channel having an opening on an inner face of said structural layer, said opening extending at least partially along said wiring channel; a window covering at least a portion of one of said plurality of diagonal structural members; and wherein said finishing layer completely overlaps said wiring channel so as to close said opening of said wiring channel, said finishing layer being removably attached to said structural layer so as to provide access to at least a portion of said wiring channel. an outer skin, a structural layer and a finishing layer adjacent an inner face of said structural layer, said side wall further comprising an insulating layer adjacent an inner face of said outer skin, said insulating layer being operative to provide at least one of a thermal and an acoustical insulation; wherein said structural layer is adjacent an inner face of said insulating layer, said structural layer having: a longitudinally aligned top door frame member; vertically aligned left and right door frame members each depending from a different end of said top door frame member, thereby defining a door opening; a longitudinal top structural member proximate said top door frame member; and a plurality of diagonal structural members oriented at an angle comprised between 1 degree and 89 degrees from said top door frame member, said plurality of diagonal structural members defining a lattice structure having a plurality of openings there in between, at least one of said plurality of diagonal structural members being connected to said longitudinal top structural member and defining a wiring channel for routing electrical wiring, said wiring channel extending downwardly and diagonally from said top structural member to an intermediate position between said top structural member and a bottom portion of said structural layer, said wiring channel having an opening on an inner face of said structural layer, said opening extending at least partially along said wiring channel; a window covering at least a portion of one of said plurality of diagonal structural members; a longitudinally aligned top door frame member; vertically aligned left and right door frame members each depending from a different end of said top door frame member, thereby defining a door opening; a longitudinal top structural member proximate said top door frame member; and a plurality of diagonal structural members oriented at an angle comprised between 1 degree and 89 degrees from said top door frame member, said plurality of diagonal structural members defining a lattice structure having a plurality of openings there in between, at least one of said plurality of diagonal structural members being connected to said longitudinal top structural member and defining a wiring channel for routing electrical wiring, said wiring channel extending downwardly and diagonally from said top structural member to an intermediate position between said top structural member and a bottom portion of said structural layer, said wiring channel having an opening on an inner face of said structural layer, said opening extending at least partially along said wiring channel; a window covering at least a portion of one of said plurality of diagonal structural members; and wherein said finishing layer completely overlaps said wiring channel so as to close said opening of said wiring channel, said finishing layer being removably attached to said structural layer so as to provide access to at least a portion of said wiring channel.