Letter: Carbon Sequestration Makes Jones Renovation An Investment In Sustainability
Photo: Pxfuel.com. Public Domain
As an Amherst resident, I want to be sure our new library is a financially responsible investment, a step toward sustainability, and a key to honoring our carbon commitment. As a mechanical engineer with four decades of construction experience, I was pleased to serve on the Jones Library Sustainability Committee to help make it so.
This project is unprecedented because it considers embodied carbon and not just operational carbon in the design process. The option in front of the voters is the greenest option.
The choice of building materials can be one of the largest variables in the carbon equation. The baseline design used concrete and steel. But the massive energy inputs required to make and move those materials would have created a huge carbon footprint, one that even a highly efficient building would take decades to erase.
With wood timber construction, the embodied carbon will be less than 1/3 the baseline. While far-out solutions to climate change imagine massive machines to capture carbon from the atmosphere and store it underground, this project will take advantage of an existing solution – trees. Trees pull carbon from our atmosphere, and building with wood will sequester that carbon, potentially for centuries.
I know this because my house and garage were built from timbers salvaged from structures built in the 1800’s. The carbon in those timbers was pulled from the atmosphere some 200 years ago and is still sequestered today.
If the library went with the earlier design, it would take over 30 years to offset the embodied carbon with operational savings. The lifetime carbon savings would be 4,500 metric tons. That’s not insignificant, but the project before the voters will do far better.
The proposed Jones Library will save 7,500 metric tons of carbon over its lifetime. Its impressive energy efficiency will enable its low-carbon construction – and the relatively tiny footprint of demolition – to be offset in just over eight years. And from then on it will pay a carbon dividend, year after year.
Todd Holland
Todd Holland is a resident of Amherst
Lower carbon embodied building materials are certainly the way to go for a totally new construction project, which, of course, the library is not.
Todd actually makes the case to Vote NO on the Jones’ demolition project. He states that the Jones proposal is unprecedented because it will use less highly embodied carbon materials. But what about wasting the existing highly embodied carbon materials already in place and already paid for by taxpayers?
It is also unprecedented that the Trustees decided to dump the entire 1993 addition of such materials into landfill without a study of adaptive reuse of this town resource. Shocking, really. The plan to destroy 40% of the current building is not a “relatively tiny footprint of demolition” as Todd states.
Adaptive reuse is a foundational tenet of sustainability that the Trustees seem determined to ignore. Fennessey Consulting Services estimates that replacing this destruction will cost $7.4 million of the total $35.3 million demolition/expansion project.
In FY 2019, the year before the pandemic, the library paid $107,344 in utility bills . Using that figure, it would take 69 years to recoup just those construction costs, not including debt service.
Thank you Todd for serving on the Library Sustainability Committee and helping the plan become more sustainable. Thanks for educating us about the importance of using wood instead of concrete and steel. Of course no one is pushing for the trustees to go back to the original plan. Rudy Perkins, as reported in the March 6th edition of the Indy, spoke at a public forum on how the plan could be pushed a lot further. I hope that has happened and I am wondering whether there is any plan for sustainability of the debris from the 40% demolition to lessen the impact of the disposal on the environment. I am sorry that your committee didn’t get involved in looking at a plan that would retrofit the Jones as it is now.
I have to say I am always a bit confused by discussions over the library project and carbon dioxide emissions. Maybe because there is no apples to apples comparison (of total lifecycle of each option–counting every step). This is how I am looking at the numbers for 3 options or apples:
One apple: The Jones Library project is built with a large addition. What were the carbon dioxide emissions from the original construction of the Jones and the addition? If the addition is removed, a larger addition built, and the interior renovated, this construction work and manufacture of the building materials will result in carbon dioxide emissions–plus the loss of some part of the earlier carbon dioxide emissions. What are these numbers? And then add in the emissions for the disposal of the older materials resulting in carbon dioxide emissions. Insulation, new energy system and energy sources will have both carbon dioxide emissions and reductions, depending on the energy source. What are all these numbers ? And are the estimated totals for this entire apple?
Second apple: doing nothing or not much to the Jones Library. No new emissions from demolition, manufacture of materials and the construction itself but also no waste or loss of past carbon dioxide emissions. Continued carbon dioxide emissions from using heating and cooling — assuming no change in the system– currently being used? These numbers? What if the energy source is switched and/or a new energy system installed? What are these numbers?
Third apple: Jones Library is renovated, keeping the older addition and no new addition. The numbers? And if the energy system and source are switched? What are these carbon dioxide emission numbers?
How do these numbers stand up next to each other? If there is an overall reduction in carbon dioxide reduction of one apple versus another, what is it? When does it happen? (Also thinking if it’s 20 years in the future these numbers might change, as different sustainable technologies and energy sources are developed.)
Janet “nails it” with this details-specific request for a comparative emissions analysis – let it be done!
My hunch is that the second apple would win “gold” – and win big if the heating and cooling systems were simply switched to ground-coupled heat-pumps.
(The third apple would win “silver” in this competition, while the first apple would be disqualified for “doping”!)