How Companies Can Tackle Construction Scope 3 Emissions

Let us paint a picture for you: you’re working a job resurfacing a road at night. Your boss tells you that you are in charge of reducing the greenhouse gas emissions-related activities. You swap out the diesel for a biofuel (hydrogenated vegetable oil); this reduces your Scope 1 emissions. You swap out the lighting with solar-powered versions, reducing your Scope 2 emissions. Everything is going great, then your boss calls you into the office to ask why you haven’t done anything about Scope 3. You’re dumbfounded; what can you do about Scope 3? Well, we are here to help you with this short venture into tackling construction Scope 3 emissions as a construction company.

Read more: Scopes 1, 2, and 3 Defined

What Does Upstream Scope 3 in Construction Businesses Look Like?

For clarity, construction Scope 3 emissions are all activities not classified within Scope 1 and Scope 2. Therefore, it only does not cover the direct release of greenhouse gases by the organisation (Scope 1), such as the case with combustion and refrigerant leakage, for example. As well as any purchased energy (Scope 2) typically present as purchased electricity. Scope 3, as a category, is consequently pretty massive and should be expected to be the majority of most companies emissions. It is also worth pointing out that Scope 3 is particularly in reference to an organisational carbon footprint/business carbon assessment (not a lifecycle assessment). This means that whilst site-specific assessments can be implemented, it is all aggregated on a company-wide basis. Additionally, we should point out that only fossil emissions and removals are considered “in-scope” activities for organisational carbon footprints. All biogenic emissions and removals are “outside of scope”. Herein, we look to explore quantification and reduction of upstream construction Scope 3 emissions. That is all activities occurring from companies you’re buying stuff from.

With all of those particulars and caveats addressed, let’s get into the meat of it: what activities within construction are likely to be the carbon hotspots (areas of most significant greenhouse gas emissions) within upstream Scope 3?

• Firstly, you’ve got all your purchased materials for the job. Bricks, cement, resin, rebar, paint, gravel, timber, This, alongside all other purchases (tools, PPE), is lumped into the useful purchased goods and services subcategory of Scope 3. It is all of the fossil emissions related to upstream processing to produce the tangible (physically there) goods you are working with.
• Next, you may have noticed that the category is purchased goods and services. Now services are more intangible (nothing physically owned); this is in relation to the emissions of those service providers in your upstream supply chain and sits in the same category.
• Additionally, some heavy equipment utilised is a larger purchase or capital expenditure. This is given its own special category to sit in.
• Of course, all of the tangible goods are transported to site. The transportation of which requires the combustion of fuels. This is referred to as upstream transport and distribution. Importantly, it also includes all paid-for transportation of goods.

An average construction organisation should expect that the above categories encompass more than 70% of company-wide emissions. With a particular hotspot on purchased goods and services.

The First Steps in Reduction… Measurement!

So, now you know where your likely hotspots are, lets start engaging the supply chain, buying reclaimed bricks and cement with pozzolanic materials (meaning natural or industrial materials like volcanic ash, fly ash, or silica funme)! It is important to walk before you can run. The first step in reduction of these upstream emissions is quantification. Here, for the baseline assessment you shall be entirely dependent on the current data collection systems implemented within your business.

It can be useful to separate it into primary, secondary, and tertiary data types. In this vein, primary data is what we are aiming for; tonnes of gravel, litres of water. This enables the use of more accurate emission factors related to said primary input data. Next, we have secondary data, typically given as the spend-based data, something we are usually tied to in the case of subcontractors. Lastly, we end up with tertiary data, gross. This is heavily rooted in assumptions, based on company knowledge and specifics of the activities being undertaken. It is sometimes necessary but highlights areas within the business activities which transparency is sub-par. Beyond carbon quantification this can lead to a whole slew of other issues within a business’s operations. Hence, implementing internal systems in these area’s is vital.

Once you have collected all of your data you must quantify your emissions using relevant emission factors to provide you with your baseline carbon footprint. We recommend using internationally recognised standards, as well as using regionally, temporally, and technologically appropriate emission factors from trusted databases. If you have any questions our team of PhD-level scientists are more than happy to help with a cooperative approach. Don’t believe what you have seen on Big Bang Theory, we’re a reasonable bunch.

Reductions, Still Dependent on Data

Now you’ve got your baseline emissions for the carbon hotpots in upstream Scope 3. The approach you can utilise for reductions which are easily monitorable and reportable shall be driven by your activity data measurement. If primary data is collected then you can look at material specific reductions. However, if secondary data is only applicable (as stated the case with subcontractors) then supply chain engagement is the way to go. Let’s have a deeper look at both of these.

Material Specific Reduction

One of the most impactful ways to reduce upstream construction Scope 3 emissions is through material procurement practices. The embodied carbon within tangible goods purchased represents a significant portion of the emissions. If you have tracked metrics for the type of goods and the primary data (tonnes, m3, L) then you can look at sourcing materials with a lower embodied carbon footprint. Generally, these materials are going to have reduced carbon impacts through:

1. Recycling process – Some materials are heavily recycled and can incorporate large amounts of recycled material such as steel and aluminium.
2. Biogenic feedstocks – Often biologically produced material such as timber, can be utilised in construction.
3. Renewable energy during manufacturing – Energy intensive manufacturing processes can be mitigated against by the use of renewable electricity.
4. One-to-one replacement materials – Often carbon intensive materials can be replaced by new materials emerging from technological advancements.
5. Waste utilisation – Some traditional waste materials are being formed into circular economies to make new different goods.

When looking to compare greenhouse gas emissions of different purchased goods from suppliers, Tunley always recommends identifying them by either an Life Cycle Assessment (LCA) or an Environmental Product Declaration (EPD). This would be a lifecycle assessment completed to ISO 14040 & 14044 with the additional product carbon footprint standard ISO 14067. Or through a verified environmental product declaration. Of course, our specialist scientists at Tunley can assist you in obtaining this for your products if your supply chain is asking for them.

Supply Chain Engagement

When you’re stuck with spend-based quantification (secondary data) and there is nowhere else to go, you have to embrace it. Rather than using generic “base” spend-based emission factors you can obtain supplier specific spend-based emission factors by engaging with your supply chain. This is something we have seen from the big tech boys such as Microsoft, requiring all their supply chain to provide quantified carbon footprint data. Tunley would recommend the following as a rough process to engaging with your supply chain:

1. Identify the top suppliers by emissions.
2. Communicate your sustainability journey and emissions.
3. Explain the process of quantification of emissions.
4. Collect and collate all of your supply chains data to get specific emission factors.
5. Re-calculate your carbon footprint accordingly.
6. Work together to reduce all the way up.

Once you have quantified spend-based carbon footprints for your subcontractors (any anyone else) you can bring this into the decision-making process. Even potentially highlighting to one supplier if their emissions are significantly higher than similar services being procuring. In this methodology you can help to reduce their footprint, which reduces yours, or source alternative providers with lower footprints due to more environmentally friendly practices.

Conclusion

Construction companies can significantly impact their carbon footprint by addressing upstream construction Scope 3 emissions. The journey begins with accurate measurement through robust data collection. Companies can then implement targeted strategies like sourcing low-carbon materials and engaging supply chain partners. These efforts not only contribute to environmental goals but also drive industry innovation and efficiency. By proactively tackling construction Scope 3 emissions, construction firms can lead in sustainability, combat climate change, and enhance their competitiveness in an increasingly carbon-conscious market.