Life Cycle Assessment and Ladybug. Why not?

Hi!
I have a rather open question to the forum. Why is there no LCA-tool embedded in the Ladybug-package?

The reason I’m asking, is that I am given a trial lecture entitled " Digital design and fabrication: Challenges, Barriers, Opportunities in Design Practice and new Research Trajectories for the reduction of carbon footprints in buildings"

I’m not yet into this topic, but my PHD-topic is into parametric detailing and fabrication of timber structures. I’ve read about Ladybug tools several times, and have always assumed there was an implemented way of doing LCA using Ladybug.

From previous forum-posts, I have read that the main issue is that databases are not sufficiently open? Is that still the case? Or are there other barriers that prevents the building industry from having a proper tool for parametric LCA?

Happy for all answers!
Thanks

Hi @Johnhaddal,
If you happen to know publicly available resources on LCA information for materials, please share and we would be interested in creating workflows around it. This questions has been asked before and we remain interested in integrating LCA in Honeybee workflows.

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Just adding my two cents here.

There is a plugin for grasshopper developed by ETH which contains LCA information for materials. It is called bombbyx. Maybe you might be interested.

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Thanks for sharing @ncatunda, I assume that this tool only works with Swiss materials. I could find their code base on Github and I will look into this. We would ideally need material databases for the North American region to start something on this front.

Yes, it is based on Swiss standards. The data was centralized in the Ecoinvent project, as far as I know. If anyone is curious, here is the link https://www.ecoinvent.org/

A little bit about it:

“The material and energy balances for the large number of building materials come from various companies, associations and research institutes in Germany and abroad. They were harmonised as part of the ecoinvent project, a joint initiative of the ETH Domain and Swiss federal offices [2] and prepared in a userfriendly manner by KBOB, eco-bau and IPB [3].”

source: SIA 2032 - Swiss standard about grey energy

There is another database I know, but it is also European (https://www.buildingtransparency.org/en/). The materials on this one are classified as “Environmental Product Declarations (EPDs)”, which apparently is different from the method that Ecoinvent uses, but I honestly know too litlle to really discuss more about it.

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hi,

this is awesome, I’m doing my thesis at the moment and I’m struggling to find a reliable source for LCA related building material data.

some problems I encountered:

changing the insulation thickness in the material example file won’t change the U-value for certain materials (e.g. Foam glass gravel (137.5 kg/m3) | 10.013)., only the GWP output - is it a missing thermal conductivity causing this (the last line was 0 from the KBOB Material component)? I guess the default setting in the material file was an unfortunate coincidence, the rest I’ve checked has a lambda assigned.

how is the U-value calculated? I assumed 1/sum(Ri), where Ri = sum(d_i/lambda_i) for the layers and 1/h_i + 1/h_e for the bounding surfaces, the latter being predetermined based on the Functionality input? I’ve checked the Github repository for Bombyx, but I’m struggling to read C# (I’m rather new to energy modelling and programming) to decode the whole property passing process.

I cannot figure out the order of these parameters:

are they related to these properties? (Found in ImpactLayer.cs on Github)

I’ve tried matching them:

at the component impact why are the two densities added? I assumed that component output would indicate properties to the component level, in this case rho_avg = d1/(d1+d2)*rho_1 + d2/(d1+d2)*rho_2?

I’m confused :frowning: …also not familiar with the ecoinvent database (familiarity could mean I don’t have these questions…), and I only have a vague undertanding of LCA in general, I would be appreciate having some guidance where to look/what to read first to understand what Bombyx is actually doing! :slight_smile:

20190409_Bombyx_material_example_fb.gh (22.7 KB)

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Hi @furtonb

Unfortunately I cannot help answering the questions. I also found the other day some weird U values, not sure if the component is putting another values in the middle or just a bug. Maybe you would want to send an email to bombyx@ibi.baug.ethz.ch. Hopefully someone there answer your questions :slight_smile:

PS: please let me know if they do, cause I am also curious :slight_smile:

This is a very interesting and timely discussion.
I believe the developer of cove tool (which I have not had the time to fully test yet) have integrated - not sure if via an API - the EC3 database

The EC3 tool is open source and good as a starting point, however it appears to be US-focused mainly, which is a bit of a limitation for someone based in EU/UK like myself.

Would it not be a matter of writing components that link to existing, open databases?

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@ncatunda Thanks, I contacted them. If I get an update, I will keep you updated.
I also linked this thread and suggested that they reply here - we’ll see.