Energy Efficiency + The All-Glass Building
As a precursor to my discussion, “The All-Glass Building – Is Energy Efficiency Possible?” at BuildingEnergy 15 next month, NESEA published an article about that very topic. In it I explored the benefits of a glass façade (daylight) and the drawbacks.
Glazed towers dominate the skylines of our cities. However, most have been designed with little thought as to the climate in which they are located or the environmental impact they might have. According to the Commercial Building Energy Consumption Survey (CBECS) in 2003, 70 percent of energy use in commercial buildings is from the lighting and HVAC systems. The performance of both of these systems is directly related to the design and performance of the building envelope. Sealed, glazed façades, now so ubiquitous, lead to higher heating and cooling loads as well as glare and thermal comfort challenges.
Despite these challenges, many design teams pursuing sustainability continue to use all-glass façades because of their ability to connect interior and exterior environments. The market continues to demand, and architects to deliver, high glazing percentages for the daylight, views, and marketing potential they provide in green buildings. Such designs are difficult to make energy efficient, but many argue that fully glazed buildings, when designed correctly don’t increase a building’s energy usage.