For this extension windows project in Stone, opening checks, frame fitting and finishing are treated as one sequence. Internal Making Good leads the review, so we repair or finish internal reveals, sill zones and decoration interfaces around the new frame, with internal making good kept as the lead check for this extension windows scope. We use frame dimensions and head interface around prepared openings, lintels, cavity closures, sill levels and external finishes, ensuring we confirm manufacturing dimensions against the surveyed opening before the replacement frame is ordered and coordinate the frame head with the retained lintel, cavity closure and internal reveal, with internal making good kept as the lead check for this extension windows scope. The last technical check is drainage paths; we keep designed frame drainage routes clear through installation and external finishing, with internal making good kept as the lead check for this extension windows scope. This supports window installation aligned with the wider extension build and finish sequence.