The BHoM EPD
The LifeCycleAssessment_Toolkit functions primarily as a suite of evaluation methods that work with EPDs. We've already taken a look at the dataset and how to create one. And you may have even skipped ahead to see how to map EPDs to your BHoM objects. In this section, let's make the connection between datasets and EPDs abundantly clear. When you create a dataset node or container, you are actually accessing Environmental Product Declarations that have been saved within the BHoM as materials that can be applied to BHoM objects.
In this section, we will look first at the creation of an EPD, all of the needed components, as well as some additional fragments that can be used to add even more specificity to your EPDs. This is primarily to help get you more comfortable with the EPD's object schema, but we also encourage you to create your own EPD datasets and share them with everyone!
Let's first take a look at the Grasshopper canvas, and how we would make a new EPD from scratch using BHoM components. Keep in mind that the BHoM UI is very minimal, so it is recommended that you rely on Intellisense when building these objects rather than searching for each individual item needed. This can be done by simply clicking and dragging the node's input and releasing to see available options. The tool will recommend all suitable matches for you!
You'll notice a couple of things as we start. The core EnvironmentalProductDeclaration object consists of 5 important input properties; Type, Environmental Metric, Quantity Type, Quantity Type Value, and Name. In order to create an EPD, we need to provide all of this information! Starting at the top:
- Type: Either product or sector, this will depend on how the EPD was created and the methods of calculation used.
- Environmental Metric: This is really how the evaluations take place within the toolkit. The metrics themselves house the impact metrics, quantities, and phase information needed for assessment.
- Quantity Type: There are several to choose from (mass, area, volume, length, and so on), but typically the EPD will only have one method by which the evaluation has been carried out. In the included datasets, these quantity types are hard-coded and if altered will significantly impact the overall evaluation. Be very careful to ensure that this property is correctly set.
- Quantity Type Value: This is the standard of measure for any given EPD. This value is set to 1 by default as most EPDs are assessing 1 of any particular product. However, this value can change for things like flooring area for example, where the item evaluated could be a percentage of area.
- Name: Whatever you would like to call your EPD.
Now you give it a try!
**Excel more your speed? Let's give it a shot too! **
Now that you know the basics behind the creation of the EPD, you're ready to either evaluate your object's metrics or compile your LCA.