Wondering if any of you have experience using the buildcarbonneutral.org quick carbon calculator.
I have a few questions about the site/landscape disturbed and installed aspect and how it affects the CO2 for projects.
I’m also curious about these questions.
Note that this tool has not been updated since 2007. My firm EHDD is working on a early-phase carbon assessment tool now that is not quite ready for sharing, but will be in the coming months. It will allow you to look at the questions you raised.
I can probably help out on this, as one of the people developing buildcarbonneutral.org (BCN) at Mithun. I can list the basics and you can let me know if there are other questions.
Working with the Lady Bird Johnson Wildflower Center (Mark Simmons and Heather Venhaus) we established the numbers for soil sequestration of carbon in the various eco-regions for the different types of vegetation. We chose the soil sequestration only because at that point there wasn’t a lot of information available about long term maintenance’s impact on above-ground biomass, and BCN was only looking at initial installation and not at long term replacement values for any of the building components either. In 2007 one of the biggest goals was to have a reasonable tool to build knowledge of the importance of embodied carbon.
If there is soil disturbance in an area of existing vegetation, that soil carbon is released so the calculator counts that as a source, in addition to the carbon related to moving and removing soil from the site. If you are disturbing a previously developed site the assumption is that it is primarily hardscape and so the soil carbon released is zero, but the movement of soil is still counted.
If there is an area that is being planted, then that counts the soil carbon as a sink and the calculator counts that into the final equation for net carbon impact on site.
If you want to hack the site, you can enter information in for each of the vegetation types individually and get a separate answer for the benefits of each of those elements individually. It will only include soil carbon sequestration however.
If you are looking for numbers for maintained landscape and how they can contribute, we have been looking at the new Pathfinder calculator that Pamela Conrad put together through Climate Positive Design - https://climatepositivedesign.com/pathfinder/ It does consider maintenance and a longer term life cycle for plantings.
Let me know if that helps. We are always interested in feedback and are looking at the feasibility of finally putting together an update after 13 years!