Green Buildings: Dow says many buildings are actually getting less efficient

Mike Kontranowski, Strategic Marketing Manager of Dow Building Solution’ Thermax brand of rigid insulating board, presented a sobering analysis of the direction of building efficiency during the Summit. Although buildings of all types have become more energy efficient on a per square foot basis for the past 50 years, many buildings constructed over the past decade have bucked the trend and have begun regressing on energy efficiency. This reversal comes despite newfound interest in “green building” among governments, occupants, and the building owners themselves, and despite the plethora of insulation, window, equipment, and other devices that yield far greater efficiencies. More surprisingly, many of the buildings are LEED (Leadership in Energy & Environmental Design) certified, because energy efficiency is only one of many metrics that accrue points needed for certification.

The proximate cause of the backslide in efficiency is a switch to less expensive aluminum wall studs in place of wood or block in recent years. Because aluminum is such a good conductor of heat, walls that are otherwise well-insulated – with insulation batts installed between the studs – see an overall insulating R-value of the wall drop in half, from 11 or more to 5. Thermal images of walls are particularly poignant, showing relatively small amounts of heat escaping from between the studs, while the studs themselves were lit up like Christmas trees.


{ Lux Research Analyst Blog | Continue reading | via Josh Wolfe }

architecture, economics, technology | May 25th, 2010