Table of Contents
What is embodied carbon?
Upfront embodied carbon refers to the emissions associated with all the activities of procuring, mining, harvesting raw materials, transforming these materials into construction products, transporting them to site and incorporating them into a building, and subsequently maintaining, replacing and removing and disposing at the end of their life.
Why does this matter?
Eleven percent of global emissions are associated with upfront embodied CO₂ emissions from new construction.
With the introduction of the revised Nearly Zero Energy standard through Part L of the Building in regulations in 2019 for both residential and non-residential buildings, the upfront embodied carbon now represents a much greater part of the whole life cycle carbon of the building, in some cases up to 50% This means that from now on the upfront embodied carbon is now as important to calculate for new buildings as the operational carbon.
What standards are relevant to calculation of embodied carbon?
There are a number of standards relevant to the calculation of the embodied carbon and other impacts of buildings. EN15978 sets out how the full life cycle carbon and other environmental impacts should be calculated setting out the modules relevant to each part of the building lifecycle.
Are embodied carbon emissions of buildings in Ireland regulated?
There are currently no definitive plans in Ireland for regulations but there are a number of positive indicators that this is likely to happen over the next five years. Holland and France have already introduced regulations, with Finland introducing regulations in 2025 and other countries likely to follow.
Changes to the EU Construction Products Directive will likely see a requirement for use of ecological footprinting of products through either EPD or Product Environmental Footprint (PEF). The EU commission has introduced the Level(s) framework.
So what is driving interest in embodied carbon calculation at the moment?
Ireland’s national certification scheme for homes – Home Performance Index awards credits for embodied carbon calculation and LCA. The international certification schemes for non residential buildings LEED and BREEAM also award credits for the calculation of Life Cycle Assessment and embodied carbon. This is driving interest amongst professionals in calculation.
However, there is also an increasing interest from the investment community in embodied carbon and this is likely to grow over the coming years.
What tools are available to use?
There are a number of tools that can used to calculate embodied carbon such as One Click LCA. This is a proprietary cloud-based tool with an annual licence fee. However, they have recently made a free version One Click LCA Planetary. This provides data for the most of the high impact products used in construction and contains all of the data from IGBC’s EPD Ireland programme.
Also, the IGBC developed Carbon Designer for Ireland, a free early-stage whole life cycle carbon assessment tool for the Irish region.Check the Carbon Designer now!
What data can I use for Ireland?
IGBC has developed the EPD Ireland programme to allow Irish manufacturers to publish verified Environmental Product Declarations (EPD). These provide the data on Global Warming potential and other environmental impacts used in the calculations. For more information www.epdireland.org. Virtually all insulation manufacturers in Ireland have now developed EPD with some gaps in other materials such as cement. You can help encourage these sectors to produce verified data by signing up to the EPD commitment.
You can also find generic data for Ireland here. Generic data is used where there is no verified manufacturer data for a product.
Where can I get training?
IGBC or its partners such as OneClick LCA provides training on the use calculation of embodied carbon and LCA.
If you want to learn how to quantify the carbon emissions associated with your building designs, register for IGBC’s “Whole Life Carbon” Training here.
See learning hub for online videos.
What is a Life Cycle?
A lifecycle of a product can be described as the extraction or harvesting of its material, the manipulation of that material into the product (or manufacturing), its release into society, its use and finally its disposal as waste. Some of that waste is then reused in one form or another but mostly it is discarded to landfill or incinerated. Products flow through society, mostly in one direction, taken from our natural environment as raw materials and returned back to our environment as emissions and waste via incinerators and landfill sites – this is the usual process in linear economics and we have reached a stage where we are realising that it cannot continue indefinitely.
What is Life Cycle Assessment (LCA)?
Life Cycle Assessment takes a process and quantifies the environmental impacts of it in order to provide meaningful data that can be compared against other processes. It does this by measuring the inputs and outputs of each step of the process. In the case of most industrial activity inputs are usually raw materials, either virgin or recycled, energy for extraction, transport and factory processing and the use of tools needed for the job. Outputs, alongside the product itself, are emissions and waste. LCA can be applied to any process at any scale, what is important is that the scope of the process that is being analysed is understood and defined at the outset, so we know the boundaries of our study.
LCA methodology and framework is covered in detail in the standards ISO 14040 – 44 – Environmental management Life cycle assessment — Requirements and guidelines
Life Cycle Assessment in the Built Environment
In the built environment the scope is usually understood and defined as the acquiring of raw materials either by extracting virgin materials from the earth or using recycled materials, manufacturing components, constructing a building, operating the building during its useful life and finally disposing of it.
These are the steps of a Life Cycle Analysis:
- Define the goal and scope of the study – what needs to be known and within what context?
- The goal is usually to define the environmental impact of producing one thing – what we call the Functional unit. It could be a simple thing, like a brick, more complex like a window with certain quantities of different materials and multiple processes, or very complex, like a building that fulfils a particular function. To produce this thing requires a process, and that is what we need to investigate.
- The scope – asks us to define this process. What are the boundaries of the system in which your process takes place? For example, if you are quarrying stone, do you include or exclude all the manufacture of the machinery and trucks? Usually you would exclude, as they are also used for other projects too, so you would probably only include the fuel used to run them during your analysis – that would be your system boundary, and it’s important that you can explain it.
- With a defined scope in place, you can then begin to quantify everything within that scope to produce an inventory that can be measured.
- Analysis and assessment – assign impact values to the inventory – if you think of things like car emissions measured in grams of CO2e per kilometre, the same can be done for grams of CO2eper kWh of energy used in a production process or kilos of CO2e per kilo of cement production. Unless it is running on 100% renewable energy, any sub-process will have an associated emissions cost.
- The interpretation is where you explain the analysis – answering questions like how does it compare to other processes? As getting perfect data is almost always impossible, what assumptions have you made? What are the limitations of your analysis? Where are the highest impacts? The hotspots? Are they justifiable/unavoidable? Is there an alternative route to lower result? Where should we focus our efforts?
- Finally, the Normalisation – breaking the study down into a comparable unit so it can be compared to other processes that produce the same output, or to put it into the context of the rest of the world, so for example if you say producing this building cost 100 tonnes of CO2e and the building is 100 square metres then that is 1 tonne, or 1000kgCO2e per square meter, and you can compare this to other buildings. You can compare it to the average person’s annual output of 8 tonnes, that gives you an idea of how it compares with other things – building this building is the equivalent of 12.5 people’s annual emissions.
Why use LCA?
In the built environment, performing an LCA provides several benefits:
- Highlighting hotspots to focus efforts on
- Can bring focus to development of a project
- Compare possible design choices for optimisation
- Gain credits in LEED, BREEAM, Home Performance Index and many other certification schemes.
- Transparency – demonstrating your efforts to reduce your impacts
- To differentiate your product in the market
- Potential future legislation, carbon tax
LCA can be time consuming and inconsistent. To counter this, standards like EN15804 for products, and EN15978 for buildings impose rules on the scope of an LCA study depending on the category of the product being analysed – PCRs. At the building level, RICS, BREEAM and LEED all have their own scopes based on EN15978, and Level(s) has a similar one we are aiming to promote across the EU. A verification process to ensure buildings measured using Levels are measured consistently is being developed, to ensure we are always using the same methodology and scope
What is Whole Life Carbon Analysis?
The entire carbon emissions associated with a building over its whole life from cradle to grave/cradle.
This includes the carbon emissions associated with the sourcing of raw materials, processing them into products or building materials, bringing them to site, construction itself, operating a building throughout its useful life and finally deconstructing it.