Cleaning: glass — wipe regularly with a soft damp cloth, using mild cleaner on the cloth (not sprayed on glass) to avoid liquid in seams; a full glass clean at least monthly keeps light and view. Frame — wipe with a damp cloth; avoid abrasive cleaners or tools that scratch the coating; use a soft brush for seam dust. Parts: gaskets — check every six months for ageing/cracking and apply rubber protectant, replacing if badly damaged; hardware — lubricate hinges, handles and locks every three months and tighten loose screws. Habits: open/close gently, especially in wind, and don't over-open casements; don't hang heavy items that deform the window. Special cases: after storms/wind inspect for cracks, deformation or leaks; in season changes wipe condensation to avoid frame corrosion.