EOL Process in building materials

[enesys-202103]

Hello everyone,

My name is Panagiotis and I am currently working on my Master’s dissertation project.

My question is:

In the first photo, for EOL Process, Do nothing has been chosen for the materials.
In the second photo, for EOL Process, Some actions have been chosen for the materials.

Nevertheless, the emissions in the first photo (Do Nothing) are less than the emissions in the second photo (Actions). Theoretically, shouldn’t be the opposite?

Thank you beforehand!

[Bernadette]

Hi Panagiotis,

thank you for your post!

The End-of-life (EOL)-process “Do nothing” assumes that neither transport to a waste plant nor waste treatment/landfilling takes place. If these actions are taken on the other hand, emissions are released. Thus, doing nothing usually has less impact than other EOL-processes.

However, EOL-processes resulting in benefits (e.g. steel recycling), represent negative emissions in the D module and in some certifications, these benefits counteract emissions from other life cycle stages, whilst in others schemes, benefits are reported separately.

Please also note that most materials are usually not simply left on site.

I hope this helps to clarify your question. Please let us know if you have more questions.

[enesys-202103]

Hello Bernadette,

Thank you very much for the clarifications.

In addition, what would you suggest to use for my dissertation project?
“Do nothing” or “Actions” ?

Maybe I should choose “Actions” and explain the reasons why the emissions are more than “Do nothing” option.

Thank you again!

[Bernadette]

Hi Panagiotis,

thanks for your reply.

I don’t know the goal and scope of your dissertation project, but in general, I would advise to

1. Set the LCA-parameters to determine the default EOL-method. These methods are explained in detail here. In general, I would opt for EPD-specific, which falls back to market scenarios if no information is available in the EPD.
2. Review the default EOL-methods for each material. The “Default scenarios and assumptions” section in data cards helps to understand these further.
3. Adjust the default EOL-method if you have more relevant information that opposes this choice.
4. Document any such changes and their reasoning e.g. in the comment of the material, so that you can retrace the calculation at a later stage.

I hope this is helpful to you. Feel free to ask any more questions if there are any.

[enesys-202103]

Hello Bernadette,

Thank you very much for your help. I have proceeded a lot with my dissertation and I would like to ask you one more question.

How could I measure the Embodied Energy of each material I have used in the project (concrete, insulation, steel reinforcement etc.) ?

Thank you berofehand!

Panagiotis

[Bernadette]

Hi Panagiotis,

thank you for your reply. According to the EN15804 standard, EPDs have to report the embodied energy of a product as well. Here is an example, showing impact categories related to energy use (excluding the input of secondary material):

However, please note that these categories are not included in the scope of Level(s) LCA +A1 or +A2 (I assume that you use one of these tools as they are included in the free student license).

If you indeed use Level(s) LCA +A1 or +A2, the workaround would be to extract the information from the EPDs and perform manual calculations. Otherwise, feel free to reach out to us and receive further information about purchasing a tool that covers the scope you want.

[enesys-202103]

Hi Bernadette,

Thank you very much for your help.

I think I am going to perform manual calculations.

Would you mind giving me an example regarding the process of a manual calculation for Embodied Carbon of a material (e.g. Reinforcement steel (rebar), generic, 0% recycled content)?

Thank you in advance.

Panagiotis

[Bernadette]

Hi Panagiotis,

thank you for your reply. The manual calculation of embodied energy would follow the same logic as for other LCA calculations:

Quantity of material * Emission factor = Emissions

The emission factor represents the emissions (in the unit of the impact category) per unit of material’s quantity for a specific life-cycle stage (e.g. A1-A3) and can be found in EPDs.

Generic datapoints don’t provide the emissions factors for the impact categories regarding embodied energy.

Example for an EPD (Reinforcement steel (rebar coils and mesh), 7850 kg/m3 (Fert)):

1. Let’s assume we use 2 tons of this product in our project.
2. We open the data card of this data point in OCL, and click on the green button “Download EPD”.
3. For the PERE (primary energy - renewable) impact indicator regarding A1-A3, we find an emission factor of 852 MJ/t of material in the EPD.
4. We calculate: A1-A3 Emissions of material used = 2 ton * 852 MJ/t = 2*852 MJ = 1704 MJ.

If you want to calculate the embodied carbon (like you mentioned in your post from 18th March), you can do this by adding the data point that you want, adding the quantity used in the respective field, as well as adjusting the values for transport, wastage etc. in the software.

I hope this helps to clarify your question.

[enesys-202103]

Hi Bernadette,

I am really thankful for your help!

Regarding the materials which don’t have EPD in OCL, how could I obtain their Embodied Energy factor?
Should I find it via verified articles/data?

Thank you in advance!

Panagiotis

[Bernadette]

Hi Panagiotis,

thank you for your answer. This topic exceeds our expertise, as it goes beyond what’s included in OCL. With this disclaimer in mind, here is some general advice for such a case:

• You could check the platform where the data was initially published (unless it is a OCL generic data point) to see if it provides the needed information for the data you are interested in
• Research featured in articles or the like could also help
• Clearly state the assumptions and limitations of your LCA calculations

[enesys-202103]

Hi Bernadette,

I really appreciate your help!

I hope the next 2 questions will be the last ones and finally finish my dissertation.

1. Assuming that we have a material (e.g. concrete)
   I suppose the Embodied Energy will be the same whether the EOL process is “Do nothing” or “Actions taken”.
   The EOL stage does not affect the Embodied Energy of the material if I am not mistaken, does it?

2. Assuming that we have the following materials:
   a) Ready-mix concrete, normal-strength, generic, C20/25 (2900/3600 PSI), 0% recycled binders in cement** (240 kg/m3 / 14.98 lbs/ft3)
   b) Ready-mix concrete, normal-strength, generic, C20/25 (2900/3600 PSI), 20% recycled binders in cement (240 kg/m3 / 14.98 lbs/ft3)

Will the Embodied Energy be the same or different because of their difference between the % recycled binders in cement?

Thank you very very much!

Have a nice weekend!

[Bernadette]

Hi Panagiotis,

thank you for your reply.

1. Generally speaking, yes it can affect the embodied energy used. For recycling e.g. steel quite a bit of energy is required, while landfilling typically requires less energy. The EPD will state what these impacts are (and the assumptions around that) - given it is included in EPD’s scope. Here is an example (assumed EOL method is landfilling, therefore only C4 emissions are reported *)
   
   

*Glass wool insulation, faced and unfaced, L = 0.031 W/mK, R = 6.45 m2K/W, 200 mm, 6.3 kg/m2, 31.5 kg/m3, Unifit TI 132 U, Classic 032, Expert LRR 032 U, FHR 032, Unifit 032, TI 432 U (Knauf)

2. Given the two resources are identical in all other specs except the recycled content, I expect that the A1-A3 impacts for the one with recycled content is lower. This is because using recycled materials typically results in lower impacts compared to impacts of virgin materials.

I hope this helps to clarify. All the best with finishing your dissertation!