A highly cost effective system offering vertical and horizontal aluminium sliding windows in a non-thermally broken format for both new build and refurbishment markets. If required the outer frame can be installed separately from the sliding panels preventing damage to the moving components on site. Construction NOR outer framework is mechanically jointed and square cut with sealant at all metal-to-metal joints. The insulated sliding panels have knock-on and wrap-around gaskets with the perimeter aluminium sections cut, sealed and jointed using self-tapping screws. Draught-proofing to both horizontal and sliding panels is by means of woolpile in extruded grooves in the outer frame. Glazing NOR sliding aluminium windows are designed to accept single glazing of 4mm, 6mm, and 6.4mm thickness. Double-glazing of 14mm and 18mm overall thickness can be accommodated.