The document discusses improving energy efficiency in historic homes. It explains that early homes were designed to be energy efficient through features like high ceilings, wide eaves, porches, and large windows for cross ventilation. Simple upgrades like weatherstripping, attic insulation, light roof colors, and energy efficient appliances can significantly reduce energy usage. More extensive upgrades such as solar panels, tankless water heaters, or replacement windows provide bigger savings but may not be appropriate for historic homes and their initial costs are difficult to recoup. The goal is to improve comfort and efficiency without compromising historic integrity.