We have many users who model their LCA from the bill of quantities/cost plan approach. When coming from this angle, the temptation to just use one template to account for all materials of the same type is very high. This may be easier in the short term, however it leads to the problem of impacts being allocated to the wrong categories, higher ambiguity of your impacts and thus a poorer quality LCA.
Note that our categorisation system is based on the RICS Method of Measurement. Read Rich’s reply at the bottom of this forum post for more detailed information on our categorisation system.
In the example below is a classic case of misallocation of impacts to the wrong categories. The following design is a building with 5 basement floors but basically nothing has been allocated under the substructure category which realistically should have foundations, walls and floors.
Closer inspection of the templates used show that all floors have been allocated to a single superstructure floor template and all concrete for foundations have been allocated to a single superstructure poured concrete template. While this is not technically ‘wrong’ as far as the total impacts go, this isn’t good practice.
CORRECT TEMPLATE USE FOR PROPER CATEGORY ALLOCATION
Below is an example of material quantities collected from a typical BOQ. For this example, we’re focusing on concrete and steel reinforcing (reo).
Before you start building your design, you can see here that we’ve split the quantities up for the materials based on their different categories – Substructure (foundations & slab on ground), Superstructure (elevated slabs, columns, lifts & stairs) and Landscaping (external works).
Here, we’ve added the templates from the appropriate categories and edited the template names with additional description (in capital letters) as per the BOQ calcs for transparency. The original template name is retained for ease of tracking.
Now when we click into the relevant category tabs, the correct templates & materials are allocated to their respective categories which makes it easy to understand and track for review.
When you’re adding templates from the library, you can toggle the category filter to make sure that the template you’ve chosen is allocated to the right category. Word of caution – do not take this feature for granted though as some templates might still have elements within that are in the wrong categories. Always worth double checking the templates once you’ve added it into your design. If you find such templates, please notify us and we will amend them ASAP.
Bulk Swap Tool
Sometimes the material elements in the templates selected are in the wrong categories or need to be assigned to the right categories. The fastest way to do this is to use the ‘Bulk Swap’ tool in the software.
You can access this tool by clicking on the green ‘Bulk Swap’ button on the top right side of the page.
This will bring you to the ‘Bulk Swap’ tool page. In this page, you can also bulk swap numerous other elements in the design such as material, transport, people, equipment, energy and water inputs (blue tabs in the top, under the design name).
Below is an animation that demonstrates the steps for changing the material category and sub-categories.