Historic homes have many inherent sustainable features. Before the middle of the twentieth century, most homeowners couldn’t rely on comprehensive and fully automated, controlled, and mechanized heating, cooling and ventilation systems, because they did not yet exist. Instead, these buildings incorporated a number of passive or manual features that responded to the need for heating, cooling, and ventilation.
- Houses were built to minimize the heat gain from the summer sun by introducing exterior balconies, porches, wide roof overhangs, awnings, and shade trees.
- Vents and shutters let air circulate while keeping out the hot sun.
- Exterior walls were also frequently finished with light colors in order to reflect the sun, helping to keep interior temperatures lower.
- On the inside, high ceilings allow hot air to rise and transom windows above doors promote air circulation.
- Chimneys are more commonly found on the outside walls to minimize heating the interior.
- In the northeast, saltbox-style houses were positioned so that the long slope of the roof directed the cold north wind up and over the house to keep the house warmer in winter.
- House and outbuildings were grouped in an L or U-shape to create a sheltered dooryard in which to work.
- In areas where the winters are cold, chimneys typically run through the center of the house to allow the heat to radiate into the rooms.
- Thick masonry or adobe walls work in both warm and cooler climates. The walls provide thermal mass to absorb the sun’s energy during the day and transfer it very slowly to the interior. This helps keep the interior cool during the day and warmer in the evening as the heat works its way through the walls.
Although these features are not present in all historic homes, most older houses incorporate at least one of these passive or manual systems, helping reduce the need for mechanized heating, cooling, and ventilation. Owners of older and historic homes can continue to use these practical features as they were originally intended, or rediscover them, making use of their great energy-saving potential.