Greening Of Existing Buildings Is Good News For Metal Construction Industry
By Scott Kriner, Green Metal Consulting
There are approximately 4.8 million existing commercial buildings in the USA. Those buildings comprise over 70 billion sq. ft. of space. However, almost 40% of these buildings were constructed prior to 1970, which is long before the first oil embargo, energy codes and the formation of the US Green Building Council (USGBC). Many believe that these existing buildings are not sustainable in the long term – with respect to business goals of the owners and the health and welfare of the occupants or workers in those buildings.
USGBC estimates that buildings in general account for 40% of the energy consumption in the US and 71% of the electricity. Existing commercial buildings alone are responsible for 20% of the nation’s total energy consumption and 50% of CO2 emissions.
Historically there has been more attention placed on the construction of new, energy efficient buildings as a way to lower energy demand and lower the environmental footprint. But the retrofitting of existing buildings has come into vogue recently. The year 2009 was the first year that more square feet of building space was certified under the LEED – Existing Buildings rating program than in the New Construction program in that year. And in 2011 the cumulative square footage of LEED-certified existing buildings surpassed LEED certification in new construction for the first time. In addition to more attention being placed on retrofitting existing buildings, the LEED EB traction was also related to the downturn in the new building construction market. USGBC expects that despite the anticipated resurgence of construction, the LEED EB program will continue to show strong growth.
Intuitively we can understand how retrofitting or renovating an existing building can help to lower the environmental impact compared to new construction. Every time we re-use a building instead of demolishing and re-rebuilding we are reducing the amount of debris being hauled to landfills. On an annual basis 136 million tons of building-related construction and demolition debris go to landfills. And yet, every year approximately 1 billion square feet of buildings are demolished and replaced with new construction in the US.
The embodied energy in the materials used in an existing building can be preserved by re-using the building in some form. And by avoiding the use of new construction materials for the bulk of the construction project the additional embedded energy in the manufacturing of those materials is negated.
The economics also favor re-using and retrofitting existing buildings. The average annual energy cost for buildings is $3/ft2. A simple energy retrofit can cost about $1/ft2 and save up to 10% of the energy load and cost. With more aggressive and complex retrofit schemes, up to 40% savings in energy can be realized, at a higher cost, but with a stronger payback. In this year’s State of the Union address, President Obama told the nation that “the easiest way to save money is to waste less energy”. Reusing and retrofitting are offering building owners some lower cost options to do just that.
When it comes to new construction, the perceived energy savings are often incentives for the building owner. It has always been assumed that the CO2 reductions related to energy production in a new energy efficient building would outweigh any negative environmental impacts associated with the construction of the building. However, a recent groundbreaking report by Preservation Green Lab, with support from the Summit Foundation, Cascadia, Skanska, Green Building Services and Quantis, shows that building re-use can offer environmental savings when compared to demolition and new construction. The findings are based on a Life Cycle Analysis methodology that compared the environmental impacts of building reuse and renovation versus new construction using a 75-year life span. The study examined four environmental impact categories and analyzed six different building types in four different climate zones. For the first time it was reported that it can take between 10-80 years for a new energy efficient building to overcome the negative environmental impacts that are created during the construction phase.
The conclusions from the Preservation Green Lab report, titled “The Greenest Building: Quantifying the Environmental Value of Building Reuse”, will undoubtedly be challenged and studied more closely by thought leaders in the building construction market. The shifting of emphasis toward reusing or retrofitting buildings will likely have an impact on the building codes, green codes, and design trends.
The metal construction industry is poised to take advantage of the growing trend in reuse and retrofitting. The features and benefits of today’s metal wall systems and roof systems are attractive to designers wishing to retrofit the building envelope, as well as the interior areas. Design flexibility, energy efficiency, durability and aesthetic appeal are just a few of the features of today’s metal roof and wall options for designers and contractors. As our society embraces recycling and reducing, our building designers and owners are also re-thinking about re-using.
Scott Kriner is the president and founder of Green Metal Consulting Inc. He is a LEED Accredited Professional who began his career in the metal construction industry in 1981. His company is a member of the U.S. Green Building Council, the California Association of Building Energy Consultants and the Residential Energy Services Network (RESNET). Scott can be reached by email at skriner1@verizon.net or by phone at (610) 966-2430. You can also visit him on the web at www.greenmetalconsulting.com.
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