For high-level uPVC windows in Nelson, the technical sequence begins with perimeter sealing, so we form a continuous weather-resistant seal around the external frame perimeter, with perimeter sealing kept as the lead check for this high-level windows scope. We then use restrictors to coordinate handle position, restrictors, opening angle, installation access and internal reveal, and we configure restrictors where controlled opening forms part of the brief, with perimeter sealing kept as the lead check for this high-level windows scope. Before closure, trims is reviewed and we coordinate internal or external trims with reveals, frame position and adjoining finishes, with perimeter sealing kept as the lead check for this high-level windows scope. The handover also covers frame position; we set the new frame at a position that works with the reveals, sill and external finish, with perimeter sealing kept as the lead check for this high-level windows scope. Together these checks support high-level glazing configured for practical controlled ventilation.