: Most modern units are A-rated , featuring multi-chambered frames and argon-filled double glazing to achieve U-values as low as 1.4 W/m²K .
: Authenticity features like run-through sash horns , deep bottom rails, and woodgrain finishes (such as Irish Oak or Anthracite Grey) make them nearly indistinguishable from original wood. Where to Buy uPVC Sash Windows Online
: Unlike timber, uPVC does not warp, rot, or peel and only requires occasional cleaning with mild soap and water.