The argument put forward by the modern window and door industry generally contains the falsehood, “new is better”. Representatives of both KU and Columbia Gas have each made it known to me that energy efficiency is not a valid reason to replace windows. So if you have decided to keep your windows, treat them right. Solid wooden windows are generally made of high quality material, in both selection of species and in selection of straight grained material that will stay true even after hundreds of years.
As part of complete reconditioning, we first steam and strip sash to remove old paint and glazing without the bother of lead dust. The processes of shop carpentry are then employed using repair methods of furniture quality and using wood species to match existing for movement and rot resistance.
Repairs to sash and sills are made with restoration quality epoxies and a carpentry method called “dutchman”. Where necessary, new rails and stiles are milled and installed using furniture grade methods for strength and durability. Original sash were designed to last hundreds of years, so it makes sense to me to put them back right to enable them to continue their long life. Yes, that is hundreds of years…how often do you hear that today from the window market?