The definition of a green or sustainable home has broadened and deepened over the decades. Experience, knowledge, and innovations developed by architects, contractors, and manufacturers have produced a set of criteria which signals that a house is thoughtfully designed and built. During a renovation, features and assets that were not considered when the home was first built can now be included. Those sustainable criteria to consider specifying in a renovation include durability, energy efficiency, comfort, and health. We’ll start out discussing each of them as they apply to windows and patio doors, and clarify the details that make a window efficient. If you’d like to receive more architects continuing education free online, then be sure to visit our homepage to learn more about our AIA continuing education.