Kaizen Windows & Doors plans dual-colour uPVC windows in Oswaldtwistle around details that are harder to correct after finishing. The first control is sill level, and we coordinate the frame base with the internal sill or window board and the external weathering detail, with sill level kept as the lead check for this dual-colour windows scope. We then coordinate sealant joints through internal finish, external finish, trims, sealant colours and adjoining decoration and allow a practical perimeter joint for movement and a neat external seal line, with sill level kept as the lead check for this dual-colour windows scope. Internal Making Good is checked before closure, while frame position is included in final handover. We repair or finish internal reveals, sill zones and decoration interfaces around the new frame and set the new frame at a position that works with the reveals, sill and external finish, keeping the installation focused on frame finishes coordinated separately to the interior and exterior appearance, with sill level kept as the lead check for this dual-colour windows scope.