On this extension windows project in Whittle-le-Woods, opening configuration is the first installation control and we confirm fixed and opening sections against ventilation, access and furniture or worktop positions, with opening configuration kept as the lead check for this extension windows scope. Kaizen Windows & Doors links installation access to prepared openings, lintels, cavity closures, sill levels and external finishes, making sure we plan handling and working access before existing frames are removed, with opening configuration kept as the lead check for this extension windows scope. We also review reveal dimensions before making good and check internal and external reveal depths so trims, plaster and handle clearances can be coordinated, with opening configuration kept as the lead check for this extension windows scope. Finally, fixing points is checked so we can position frame fixings to suit the opening, frame profile and surrounding substrate, helping deliver window installation aligned with the wider extension build and finish sequence, with opening configuration kept as the lead check for this extension windows scope.