GR Window and Door specialists Ltd offer a full restoration, repair and draught-proof service to existing timber box sash and case windows. Adding draught proofing and fully restoring poorly installed sash and case windows can reduce the heat loss by up to 90%. Restoring sash and case windows is a highly skilled job. We provide the highest quality service and use only the best materials. From minor resin repairs, missing putty, and broken panes. Our tradesmen are able to return your windows to their original condition.