Preservation is the up-and-coming green. Now, how could that be? We all grew up being told that old buildings are too expensive to heat, the windows leak, there is no insulation, they are drafty, they cost too much to repair and maintain. What if you were presented with a different perspective? Would you begin to look at our older buildings differently? Just as recycling is replacing our old throwaway ethic, "embodied energy" is joining the lexicon of sustainable development.
Embodied energy is the total amount of energy required to extract, process, package, transport, install and recycle or dispose of materials that make up a building's construction. In this context, the energy consumed to construct a new building can be 15 to 30 times the annual energy use of that building once it's constructed and put into use. International studies have found that the greenhouse gas break-even point for new building construction is anywhere from 15 to 25 years. Only after that initial period does a new building - no matter how green - result in a reduction in emissions. Before the break-even point, this new building is creating an increase in emissions.
The break-even point is moved even further out than 25 years if the emissions from demolition of existing facilities to make way for a new building are factored into the equation. These impacts would include the energy to dismantle or demolish the structure, dispose of the debris, remove the salvageable parts, maintain the disposal site through time and mitigate the disruption of the surrounding context caused by demolition and construction activities (the base area and downtown are excellent local examples).
It makes sense, therefore, that the embodied energy savings increase dramatically as a building's life stretches beyond 50 years. Does this mean that we also ought to pay more attention to the value of our older buildings in reducing our carbon footprint, and doing it cost effectively?
Historic preservation - or heritage conservation - at its root is the practice of maintaining and repairing buildings of historical significance (as well as structures and objects). The longer a building is neglected, the more it deteriorates and the costlier it becomes to repair. If we maintain our buildings as needed and occasionally update their key components - even if we are preserving the buildings' historic integrity - they will provide good service for generations. They are sustainable - and green.
Recycling widely is accepted to be green and sustainable. Reusing a historic building is the greenest of green: We are recycling the whole thing, not just the parts. If we are to take reduction of our carbon footprint seriously, green preservation - recycling, maintenance and repair, and retrofitting of historic buildings (as well as existing and older buildings) - will deliver more reduction of carbon in a shorter period of time using far less embodied energy (a lighter touch) than constructing new, green buildings.
By now, we all have heard America's buildings consume 43 percent of our annual energy output, cause about the same percentage of our greenhouse gas emissions and use 75 percent of our annual electricity output. It should come as no surprise, then, that the building sector - our built environment - was identified in the United Nations' 2007 Intergovernmental Panel on Climate Change Report as the best opportunity for cost-effective mitigation of greenhouse gas emissions.
In the whole building stock the largest portion of carbon savings by 2030 is in retrofitting existing buildings and replacing energy using equipment because of the slow turnover of stock.
As we hear more about LEED and other green rating systems and people in higher and higher positions of power espouse the green building theme, isn't it good to know that historic preservation - heritage conservation - is not only consistent with a sustainable future but essential to achieving it?
This is why our Colorado Mountain College Alpine Campus and Historic Routt County will be reaching out to the sustainable building community to collaborate on teaching the skills our developers, contractors and trades people will need to retrofit and upgrade older and historic buildings in ways that preserve their integrity.
For more information about this degree and certificate program, please call 875-1305 or e-mail hrc@historicroutt
I am indebted to Steve Tilly and his essay in the Spring 2009 Forum Journal entitled, "Positioning Preservation in the Center of the Green Arena."
Townsend H. Anderson is the executive director of Historic Routt County.