As you may be aware, the City of Cambridge, Massachusetts, became the latest city in July 2014 that mandates energy performance benchmarking and disclosure for large commercial, institutional and multi-family buildings. By the end of 2014, energy performance data would be reported for municipal buildings. Non-residential buildings over 50,000 square feet and residential buildings with 50 or more units will be required to report their energy use for the previous year to the City on an annual basis, starting from May 2015. This is the 10th city in the U.S. to have such mandate, after Austin, Chicago, Minneapolis, Philadelphia, New York City, Seattle, San Francisco, and Washington, D.C. and Boston. I expect this list to grow longer with an accelerated pace, and I suspect eventually building energy performance benchmarking and reporting will become a mandate in every city. That will be another major milestone in the history of building design and construction.
It is easier to understand the significance of this event if we put it in perspective:
In 1902, the first air-conditioning systems were installed in office buildings. The use of air-conditioning technology fundamentally changed the way architects design buildings. Very large floor plates were made practical. Building energy consumption became more significant. The designer of an air-conditioning system had only one (or maybe two, if including humidity) target to hit: to achieve the temperature set point of the space.
85 years later, in 1987, the National Appliance Energy Conservation Act mandates minimum energy efficiency for room and central air-conditioners. In the same year, the Montreal Protocol was created as an international agreement to phase out CFC refrigerant, a chemical that contribute to deplete the earth’s ozone layer.
7 years later, in 1992, using guidelines developed by the American Society of Heating, Refrigerating and Air Conditioning Engineers, the U.S. Energy Policy Act established the minimum energy efficiency standards for commercial buildings. Energy became an important aspect to consider in building design. And one year later, in 1993, the U.S. Green Building Council was established to promote sustainability in the building and construction industry. Keep in mind that buildings account for one third of energy consumption in the U.S. and a significant portion of greenhouse gas emissions.
7 years later, in 2000, LEED green building rating system was established to guide sustainable building design and construction practices. The following decade saw the LEED rating system continually evolve, improve and cover more building types and goes wider and deeper in building design and construction practice. The designers of a building air-conditioning system and other building systems, and in fact the entire building design and construction team, now have a matrix of targets to hit for a potential LEED certified building. For an HVAC engineer, the days of simply designing the air-conditioning system to satisfy the thermostat and then celebrate are gone.
8 years later, in 2008, the City of Austin and Washington DC enacted Energy Conservation Audit & Disclosure Ordinance and Clean and Affordable Energy Act, respectively, that mandate building energy performance benchmarking and reporting.
From 2008 to date, more cities enact similar ordinances, with the City of Cambridge being the latest. Similar laws and regulations are being passed in countries across the globe in recent years.
My friend, the picture is clear: with building energy performance being systematically measured, reported, and then analyzed, building energy consumption is becoming a design target in itself, and satisfying the thermostat alone like people did 100 years ago, is far from being sufficient to the owner, to the design team, to our society, and to your competitor. When the data for comparison is readily available, such as total energy consumption expressed in kbtu/sq-ft, one can easily imagine that the end result of a building designer and construction team will be ranked and commented on.
The next time when you chat with your colleagues, his or her question for you may be: hey, what is the national ranking of your so-and-so building in energy consumption? My friend, will your answer make you proud?
Very Truly Yours,
George Hu, PE, LEED AP, President
AWE | Air Water Energy Engineers, Inc.
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