It’s cost-effective to restore. Full restoration typically costs slightly less than the best, high-end replacements and that’s true even if you don’t consider which one is more lasting. But that assessment is important particularly in our disposable-prone society. Replacements are what they say: replacements; built to be replaced, again and again, and again. The National Trust for Historic Preservation estimates that the time period to recover the cost of replacement windows with installation through energy savings may take 40 years. That’s too long if you consider the fact that even the best replacements may last 20-25 years.