151
category. This is a time-saving measure when the same material is used across families. For instance, if multiple window sizes have the same frame or glass material,
the definition can easily be copied between them. The “Isolate in Revit View” option
allows users to quickly see where in the Revit model a material is located to better
understand what they are defining. Any information entered in Tally is automatically saved so long as the Revit file itself is saved. This gives users the ability to
come back to the WBLCA study as they are working, to update any material definitions or to rerun the study after they have made changes to the design in Revit.
8.4.3.4 Save Report
Once all of the materials have been assigned in Tally, hitting the “Save Report” button will lead to the last round of information that must be entered before generating
the results of the study. This page asks for general information about the project
including the location and gross building area. The “Expected Building Life,” or
service life, is determined in the goal and scope phase of the study and is entered
here. Tally then provides a box for the user to write out the goal and scope of the
assessment. Carefully documenting this is important in using and understanding the
results of a study, especially when trying to interpret the results of a study someone
else carried out.
Tally defaults to including biogenic carbon, but this is an option that can be controlled by the user. Biogenic carbon is a widely debated topic surrounding LCA
studies. Organic materials, such as wood, sequester carbon as they grow. Although
processing wood to be used in a building will release some carbon dioxide, this is
often far less than the amount sequestered in the material itself. According to a study
conducted by Arup on the global warming/cooling effects of timber structural materials, the emissions account for less than half of the sequestered carbon, even with
longer transport distances (Fig. 8.10). This is only true of wood that comes from a
sustainably managed forest, however. Timber from non-sustainable forestry practices still has the potential to emit less carbon than other structural alternatives, like
concrete, but overall the wood structure still has a “positive” (meaning carbon dioxide will be released into the atmosphere not that the overall results are beneficial)
carbon footprint.
Including biogenic carbon in a Tally study will account for a “negative” carbon
footprint for these organic materials, meaning they store more carbon than is
released in the manufacturing process. However, there are several approaches to
accounting for biogenic carbon. Each has its own challenges. Issues ranging from
increased uncertainty to not accounting for deforestation make it a difficult topic to
handle within an LCA study (Carbon Leadership Forum 2020). One argument in
favor of considering biogenic carbon in the calculation, especially when wood
makes up a large percentage of the overall mass of a building, recognizes the useful
life span of a building and the benefit conferred by sequestering carbon over many
decades and possibly a century or more. This appropriately intervenes over the time
scale to mitigate the negative environmental impacts of an excess buildup of GHG
8.4 WBLCA Tools
category. This is a time-saving measure when the same material is used across families. For instance, if multiple window sizes have the same frame or glass material,
the definition can easily be copied between them. The “Isolate in Revit View” option
allows users to quickly see where in the Revit model a material is located to better
understand what they are defining. Any information entered in Tally is automatically saved so long as the Revit file itself is saved. This gives users the ability to
come back to the WBLCA study as they are working, to update any material definitions or to rerun the study after they have made changes to the design in Revit.
8.4.3.4 Save Report
Once all of the materials have been assigned in Tally, hitting the “Save Report” button will lead to the last round of information that must be entered before generating
the results of the study. This page asks for general information about the project
including the location and gross building area. The “Expected Building Life,” or
service life, is determined in the goal and scope phase of the study and is entered
here. Tally then provides a box for the user to write out the goal and scope of the
assessment. Carefully documenting this is important in using and understanding the
results of a study, especially when trying to interpret the results of a study someone
else carried out.
Tally defaults to including biogenic carbon, but this is an option that can be controlled by the user. Biogenic carbon is a widely debated topic surrounding LCA
studies. Organic materials, such as wood, sequester carbon as they grow. Although
processing wood to be used in a building will release some carbon dioxide, this is
often far less than the amount sequestered in the material itself. According to a study
conducted by Arup on the global warming/cooling effects of timber structural materials, the emissions account for less than half of the sequestered carbon, even with
longer transport distances (Fig. 8.10). This is only true of wood that comes from a
sustainably managed forest, however. Timber from non-sustainable forestry practices still has the potential to emit less carbon than other structural alternatives, like
concrete, but overall the wood structure still has a “positive” (meaning carbon dioxide will be released into the atmosphere not that the overall results are beneficial)
carbon footprint.
Including biogenic carbon in a Tally study will account for a “negative” carbon
footprint for these organic materials, meaning they store more carbon than is
released in the manufacturing process. However, there are several approaches to
accounting for biogenic carbon. Each has its own challenges. Issues ranging from
increased uncertainty to not accounting for deforestation make it a difficult topic to
handle within an LCA study (Carbon Leadership Forum 2020). One argument in
favor of considering biogenic carbon in the calculation, especially when wood
makes up a large percentage of the overall mass of a building, recognizes the useful
life span of a building and the benefit conferred by sequestering carbon over many
decades and possibly a century or more. This appropriately intervenes over the time
scale to mitigate the negative environmental impacts of an excess buildup of GHG
8.4 WBLCA Tools