Windows are arguably the most important architectural element in a home, impacting the appearance, comfort, energy use, ventilation, and overall enjoyment of our homes in a number of ways – some not so obvious. This interactive session will explore important details concerning windows, including how they impact comfort, how they can be used to supplement a heating system and assist with "passive survivability" when the power fails (with real data from four homes), and their impact on annual energy use. We will cover window construction, the meaning of the various performance parameters, the impact of windows on home floor-planning and design, construction and space heating and cooling mechanicals, and window considerations for zero net energy homes, Passive House and Deep Energy Retrofits. Bring your opinions and questions!