Hi all. We are looking to complete life cycle assessments (potentially also publish EPDs) for a landscaping and living wall company. I can’t seem to find any guidance on how to account for organic products (e.g. plants, mulches, soils, etc.) as part of LCAs or if this is even possible. We are specifically looking at two products here: plants that are grown and matured for 2 years before installing in living walls; and soil substrates (specific mixes for different uses). Any help/ advice would be really appreciated. Thanks!
Hi Akos!
It is possible and there are some EPDs published for green roof systems. Conceptually the LCA would be no different than any other LCA, i.e you need inputs and output for every stage of the lifecycle of the wall. The standard to follow would be 15804+A2. The reason it could be a little challenging is because the required datasets for different plant species, soils and fertilizers are scarce and you will have to either collect upstream data or make do with proxies. Also, some research would be required on how to calculate the sequestration of different plant species (there are studies available). I would advise to start with reading a couple published EPDs of green roofing systems and this paper (Pollutants | Free Full-Text | Maximising CO2 Sequestration in the City: The Role of Green Walls in Sustainable Urban Development).
Hi Hetal. Thanks for the detailed response! This is all very interesting and as you highlighted, there don’t seem to be many existing datapoints. Based on some discussions with companies/ manufacturers, the soil/ mulch mixes seem to be relatively easy to account for as the individual components all have relevant datapoints. Plants, trees, wildlife meadows are more difficult as they remove CO2 from the air throughout their life. The amount of water, soil, fertilisers, pesticides, transport, etc. are again not that difficult to account for. Hopefully we are starting calculations for a combination of the above and will provide an update once these are concluded.
I agree, accounting for biogenic CO2 sequestration in different plant species is a study in itself. We would be very interested in knowing more about your study as you progress. Yes, please keep us updated…Hetal