References
References that I have used in creating this app.
IStructE - How to Calculate Embodied Carbon
Net Zero Carbon Building Standard (NZCBS)
Inventory of Carbon and Energy (ICE) database
Carbon factors
Many of the embodied carbon factors are based on the Institution of Structural Engineer's (IStructE) report: How to Calculate Embodied Carbon. I have rounded and approximated numbers from there, because for a mobile app like this I think it is more important to have an accessible interface than to have precise numbers. So for example, rather than have 10 different concrete numbers with 3 significant figures, I have provided 3 numbers (structural, high strength, non-structural) with 2 significant figures. The intention is to let you play with the numbers, using reasonable assumptions, not to give you a 'correct' value. I could talk for hours about what 'correct' means in this context, but suffice to say that I don't think it really exists.
I haven't used the ICE numbers directly, though the IStructE numbers make use of them. It is such a foundational piece of work, however, that I think it should be included here as a reference. It is what made embodied carbon calculations in the construction industry feasible in the first place and it remains an invaluable resource. You really should take a look.
The operational carbon numbers are taken from the NZCBS pilot version, using the 2025 energy use intensity limits as the starting point. I have taken those as the Low energy figures for each building type, whilst the General and High figures are 150% and 200% of those numbers respectively. Obviously this is a pretty rough approach, but it gives us something to work with that is based on a reputable and publically available source. You only have to look at the tables in the source document to see that an app like this can never reflect all the nuances without becoming unwieldy. As with the rest of the app, my target was to provide something reasonable and clearly explained rather than try to accommodate all the complexity of real projects. I don't have a number for hospitals, as the category is so broad that any attempt to generalise would be nonsense.
Carbon Footprint Ltd have made global electricity carbon factors available and open source via the Carbon Data Intelligence website. I have selected a few that I assume will be most commonly used within WLCeh? and/or that I think help to show the range of figures (eg France is very low, Germany is pretty high) plus some generic ones, but you can go to the website, or a number of other sources, and overwrite the figure in WLCeh? with your preferred number.
Pexels
The images on this site, and the app, are from pexels.com. Those images are royalty free and without them the whole thing would be a lot more boring to look at. So thanks to pexels.
In particular, I have used images from pixabay, Serhii Bondarchuk, Peter Muscutt. So special thanks goes to them.