The document discusses best practices for historic preservation and maintaining old windows in historic buildings. It recommends documenting existing conditions, numbering windows and parts for tracking repairs, and performing repairs like dutchmen, epoxy, and replacement in kind when necessary. Gentle and reversible methods should be used to preserve original materials. Hardware should also be preserved or replaced with like materials. Weather stripping can help maintain function while meeting energy efficiency goals. Historic preservation plays a key role in sustainable development.