Thrive In Construction with Darren Evans

Ep. 82 Concrete, Carbon & Change: Nia Bell on Net Zero Construction

• Darren Evans

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Concrete is the backbone of modern construction—but it’s also one of the largest contributors to global carbon emissions.

In this episode of Thrive in Construction, Darren Evans speaks with Nia Bell, Programme Manager at the Climate Group and lead of the ConcreteZero initiative. Nia shares how her team is working with global industry leaders to create a market for low and near net zero carbon concrete, driving real-world change in one of the world’s most carbon-intensive industries.

Key Highlights:
The Carbon Challenge of Concrete: Why cement production accounts for up to 90% of concrete’s emissions, and how innovation can transform this critical material.

ConcreteZero & Global Collaboration: How leading corporates are banding together to demand low-carbon solutions—and why demand signals are the key to industry-wide change.

The Power of Data & Standards: From UK benchmarks to global initiatives like Singapore’s market mapping, Nia explains how data transparency, EPDs, and benchmarks are accelerating progress.

Policy, Procurement & Early Engagement: Why clients, contractors, and engineers must work together early to embed sustainability into projects from day one.

A Global Perspective: The scale of the challenge—a city the size of Paris built every week worldwide—and the urgent need for systemic solutions that go beyond cost alone.

This episode is essential for architects, developers, contractors, sustainability consultants, and policy makers who want to stay ahead of the curve in decarbonizing construction.

If you want to see our other insightful podcasts, click here:https://www.youtube.com/playlist?list=PLOHI_yaqB2U8KWbsfJDPCoYEfOh-TTnip

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LinkedIn: https://www.linkedin.com/showcase/thrive-in-construction-podcast/
Our Website: https://darren-evans.co.uk/

Links:
Nia's LinkedIn: https://www.linkedin.com/in/nia-bell-a6060235/
Climate Group LinkedIn: https://www.linkedin.com/company/the-climate-group/
Climate Group Website: https://www.theclimategroup.org/

#SustainableConstruction #NetZeroConcrete #ThriveInConstruction #ConcreteZero #EmbodiedCarbon #Decarbonisation #BuiltEnvironment #ClimateAction #ConstructionPodcast

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Nia Bell:

So I manage the Concrete Zero Initiative. So the focus is on creating a global market for low and near or net zero carbon concrete. So that's, you know, very not academic. This is ideally realizing change in the real economy through our members who are kind of leading corporates in this space me, through our members who are kind of leading corporates in this space. So yes, there's a lot of people and process and yes, there's some book work, but what we really push for is real world and focus being carbon reduction.

Darren Evans:

So how do you create low carbon or zero carbon concrete?

Nia Bell:

So the material itself. So that's really interesting. And, to be fair, I did listen to one of your earlier podcasts, um, so there was a representative from ceratec who, um, being an innovator in this space, gave some really nice explanations of some of the green chemistry, some of the material science that goes into the development of these concretes. So, yeah, so, so yeah, I can probably give it a little bit of a summary here, but I would also recommend maybe dipping back into that episode. So yeah, the concrete is made up of cement, as well as aggregates, sand and water primarily, and some other additives and some other additives, and it's a carbon impact. Maybe 85 90 percent of it sits within the cement, even though if you were to look at how much cement is in concrete, it's relatively little. So it's, it's the glue that holds everything together. Um, you know it wouldn't be concrete without it, but in terms of mass, it's mostly stone and sand.

Nia Bell:

But this cement is primarily made using very high energy processes heating minerals, rocks, limestone up to really high temperatures, and so there's the fuel in the heating, but there's also a chemical reaction that happens and releases carbon dioxide. So that's the challenge with the ways that material scientists look at reducing the carbon in concrete is to substitute in lower carbon materials instead of the cement. So when I say cement, that instead of the cement. So when I say cement, that's ordinary Portland cement. And the substitutes, there are many. There are some that are kind of common, well used, you know, within current standards, and those include slags from steel production, fly ash from coal-fired power stations. So maybe not your ideal green solutions, but those are the ones that are readily available and there's a lot of energy. And focus now on extending and diversifying the materials that we can use in this way, and that includes clays, um, as well as uh, uh, pozolone, lots of women um.

Darren Evans:

Clays as well as um, different types of minerals and chemicals so, in essence, what you're saying, then, is you take away the cement and you take a by-product, or what some may class as a waste product from something else and use that as a replacement for the cement, and so by doing that, that means the concrete is lower in terms of carbon emissions yes, it's lower, and I would say there's a limit you can get to using these kind of off-the-shelf substitutions that we just talked about.

Nia Bell:

There is a limit to how much of these other materials you can put in, and that's where the more advanced chemistries and interventions are being sought.

Nia Bell:

So there's lots of great thinkers addressing this from the supply side, from the material chemistry side, and I think it's very interesting. We at Concrete Zero are keeping a close eye and we're doing what we can to kind of support that kind of activity that's being led by the innovators and the concrete suppliers and the industry organisations that represent them. Concrete Zero sits in a slightly interesting place, being that our members don't produce concrete or cement. They're the ones that use the materials, and that puts them in a very interesting position in terms of shaping, driving, influencing the market, and I think it's a sort of a very important part of the story. Ultimately, any transition in the concrete material will have to be implemented on construction sites. The people doing that implementation are the constructors and they're obviously been influenced by the decisions of the engineers and the choices of the clients, and that is the space that we at Concrete Zero think is a very important perspective, a very important lever in itself to bring into the conversation around tackling concrete emissions.

Darren Evans:

You mentioned before about the conversation I had with Barney from Ceratec and he went into great detail of his approach. The thing as well that he mentioned is that the industry, as in the cement industry or the concrete industry, have got a very well-established business model that works well financially for them and so that they were really hesitant to have a disruptor come in and disrupt their well-oiled flow of business, well-oiled flow of uh of business. And it's interesting that you mentioned that your clients, or that your members, sorry are actually users of the cement. So is is your? So? First of all, there's two questions. One of them is do you agree with barney? Are the forces at play to try and keep the status quo? Second question would be are you looking to drive a change within the market so that the market is demanding net zero cement as opposed to the current model, which is the market is demanding net zero cement as opposed to the current model, which is the market is just supplied with cement and the whole net zero thing? Well, don't worry about that.

Nia Bell:

Yeah right, I'll take the first question first. So I think the industry is very efficient, the supply chain is very efficient to responding to the demand. So, it isn't just on the supply side. It needs to be hand in hand with a strong, consistent, clear demand signal. So hopefully what we're trying to advance at Concrete Zero will help that answer. Concrete zero will help that, um, what will? What is needed to get to net zero?

Nia Bell:

concrete is going to be a transition and that does include changing the, the physical materials, and that will require shifting the supply chains, so changing the current model. But in terms of who's best place, in many respects, to realize those changes, um, I, I think we've got to give credit to the the depth of expertise in in the current sector, and you know they are the ones that are sort of primed to be able to respond to the shift. Hopefully, because it is urgent, I would say, there is a need to accelerate what is currently being put on the market currently being put on the market, um, so we, we really hope that, um, there there are changes in the market that will result in measurable reductions in what our members can report on their projects, but on overall. So both for the uk and but also in other markets. So what we see in the uk is a relatively mature market.

Nia Bell:

So, um, we're not building that much faster or that much slower than we have been over the you know, previous decades, so it's pretty, uh, consistent. But, um, that is not the case in lots and lots of markets. So, um, there are estimates that say you know, globally, a city the size of paris is being built weekly, so there's a huge amount of concrete. So, if you think globally in developing countries, and obviously concrete is not the only material, but there is sort of a need to support this growth as well as realizing the global sort of net zero ambitions. That might be an only first question to be fair.

Darren Evans:

Yeah, yeah, and and it's interesting that you mentioned that there's a city the size of paris being built, say, weekly. So globally, a city is being constructed the size of paris each week yeah, so know, distributed the building, a building worth of city. Yeah, across the globe. Paris is being built across the globe, but spread out across the globe as opposed to one country.

Nia Bell:

Yeah, and that's significant, though, across the globe major countries where that development is happening includes india. China has obviously had a lot of building and that is slowing but it's still. They're still building very fast. As well as pretty much everywhere in the global south. Um are aspiring or are meeting their housing needs for growing populations and that requires considerable construction materials. So there's concrete decarbonisation globally.

Nia Bell:

But the context is very important. So what we experience in the UK is very different to in other markets. We as Climate Group so to maybe step back, we're an international not-for-profit for profit, so that gives us some ability to start to work in different markets on different topics. So, as I said, I manage the Concrete Zero initiative but I have colleagues who work in renewable energy and transport, steel and food and these are other corporate initiatives that bring leaders together to shape and influence policy and the other requirements they need to realize the lower carbon future in these high intensity areas. And that means I've got colleagues in New York and Amsterdam, India and Beijing as well. So not all working on concrete but working in these different areas and it's definitely a very strong work to pull in to start to understand the context in these different markets.

Darren Evans:

So, going into the second part of my question, which is more around um trying to maintain the status quo, think for these was that not my second?

Nia Bell:

that was the first part, but the second part, I believe it was about the sort of why the demand signal.

Darren Evans:

Okay okay.

Nia Bell:

So yes, Asking, how do you ask for low carbon concrete?

Darren Evans:

Yeah.

Nia Bell:

Some of the work we did in the early days was come up with a definition. When we say low carbon concrete, do you hear the same, do you take away the same meaning as me? And in the UK, where we first established, we were very lucky to be able to pull on some work by a group of volunteers called the Lower Carbon Concrete Group who went through quite an amazing exercise of trying to map the embodied carbon of all the concrete on the UK market. So it's called the Low Carbon Concrete Group Market Benchmark. It's a graph, ultimately, but for different concrete strengths. It shows the distribution. So you're the lowest embodied carbon on the market, the highest, and then the distribution in between. That is really a very, very useful resource to be able to say um, to be able to use um and to be able to say okay. When I say lower carbon concrete, I mean this on this graph. Uk is quite unique in being able to have that resource, um and I have a sort of a lot of respect for the team who developed that first market benchmark um.

Nia Bell:

It's now in its fourth, fifth iteration, so you know that you need to evolve it, you need to maintain it. Every year, hopefully you see an improvement and you need to evolve it. You need to maintain it every year. Hopefully, you see an improvement and you need to track that because we're trying to replicate it in Singapore at the moment. So the learning from the UK team bringing it to Singapore, trying to get them that visibility of what is the embodied carbon on their market, so that the concrete users can ask the suppliers I want this embodied carbon. It looks like you can do it, or I want to be part of the movement driving improvements. Um, so I want you to be able to supply me a concrete with significantly lower carbon than the average, and that's you know, if everybody's asking for better than the average, the average moves down and that's what we really need to see because normally I guess when someone's looking to make a decision on purchasing concrete, the thing that's driving them predominantly would be how much is it per?

Nia Bell:

square. This is another stat which I find quite interesting. So, over a whole project, construction project, concrete may contribute around 2%, 4% I'd say lower single digits to the overall price cost. However, in terms of the carbon impact of that construction project, it's likely to be 40% or more. So that's an order of magnitude shift.

Nia Bell:

So we're finding that, with the realization of the carbon impacts of the concrete, it is shifting more attention onto the choices being made around concrete on construction projects. So, whereas, yeah, they might have only been looking at the price, um, but, to be honest, um, when it's, you know, they may not have been looking that hard if it was, you know, only two percent of the price, we find that it is not unusual for, um, you know, major clients to have no idea how much concrete was used on a project. So, ultimately, why do they need to know? In a way, so the contractors manage the concrete and they do a great job and it is built. So what's the value? Maybe previously, what was the value of really knowing how much concrete was used, but when you realize the carbon impact of that concrete, it sort of makes the case of understanding the concrete a little bit better 100%.

Darren Evans:

And as you're speaking now'm thinking, yeah, actually that rings true, that that would just be picked up by the contractors yeah this is the price that I'm paying for you to deliver this. Go and do it yeah.

Nia Bell:

So we think there's probably a case for, you know, paying more attention to concrete and the choices around it, and so, with our members, we worked to make this demand signal. So we defined low carbon concrete. Another part of the membership is making a commitment to decarbonize it. So those are time bound. So time bound commitments to reduce the embodied carbon of your concrete by such an amount. So we've got a net zero 2050 target, but also introduced interim targets for procuring or specifying or otherwise using different because people, you know, interact with concrete in different capacities.

Nia Bell:

On the demand side, 30% below the threshold, the low carbon threshold 2025, and then 50% by 2030. So those commitments get people to sit up up as well, get people to take notice, um, and question their choices, um, and yeah, so we, we think that is a really strong mechanism for um unlocking some of the I, you know, having, uh, got to know the members I've been in the role a year now um, there's a lot of really ingenious people, people who know concrete, you know backwards, forwards, every which way, and they're very, very knowledgeable, they're very skilled and it's really, you know, enabling them to put some of their focus onto the carbon optimization they already optimize for program and for cost and for multitudes of other performance characteristics. So it is, in a way, absolutely doable, but it's there are sort of probably cultural, organizational, structural, um hurdles that our members are working through. So, and by working through those things, they're obviously at the front edge of what is going to be a industry-wide transition and, yeah, really looking forward to, um, yeah, the progress they're making sustainable construction.

Darren Evans:

Simple terms, terms. What does it mean? Because there was a survey done and we found in this survey that 69% of stakeholders and 60% of the public see sustainable construction as a priority, but in that only 28% of professionals feel that they really understand it. Yeah, I think that's fair. So, within that there, how would you explain sustainable construction so that more than 28% would understand exactly what it means?

Nia Bell:

Yeah, what it means. Yeah, um, this. I think this is sort of more of a it's it's. We're all probably drawn towards what we're more familiar with when that with our in our everyday lives. It's probably more just our human condition that we know what to do in terms of how to save energy in our homes. We know how to make sustainable choices, maybe with our food, we know the basics around reducing the impact of travel choices, but when it comes to choices around the built environment and construction, it is just that little bit further removed from our everyday experience. And I and it's very hard for I'd say this is more general.

Nia Bell:

This is for lay people to really appreciate, um, where to start, what to ask, what to do um, and I think obviously there's a lot of people who work in the construction sector who really want to do the right thing and have a have not not always have have full remit to to follow that through um. So I think there's probably, yeah, an exciting period ahead where, if we can introduce um, the right processes and systems are always very effective in terms of, like, just scaling and getting things done. So that might be one mechanism, but but also just encouraging everyone to care, I think a bit more about it. So it's okay to care about concrete, it's okay, care to question um, it's, there's. I think there's a lot of people who, once you get under the skin of all the different factors that come into, uh, you know, optimizing all the different facets of concrete, it can get very fascinating.

Darren Evans:

So, yeah, what, uh, what is there that people in the industry can do to try and help those outside of the industry bubble to have a better understanding or appreciation?

Nia Bell:

I think that's, yeah, very interesting and something we're very active on at the moment, one reason being that for the construction sector to achieve their potential in this space, it needs the right regulatory framework around it, and that means getting the appropriate information at the appropriate level and fully evidenced to the policymakers who do want to see this shift happen and they want to hear from the industry in how best they can support it. There's a consultation going on over the summer from Desnes in the UK and it's all it's actually. Actually. They're trying to cover a lot, but just on one little topic, um, they want to introduce product classifications, so, um, and this is something, and in quite a of cases, you get good learnings from other sectors. This is like your energy rating on a fridge, where you've got different classifications for energy usage, similarly for embodied carbon, and it's again it's to help in the communication, and that can be within the construction sector, but also outside the construction sector, and I think some of those kind of tools could be really helpful to bringing more people into the conversation.

Darren Evans:

I think that that is really, really important is how do you take something which is viewed by most of the world, or most of the country, is complex, um, and make it digestible? How do you take all of these different data points, of which embodied carbon is one of them, and then turn that into something that means something to someone, as they're passing by and they've got two seconds to take a glance and make a decision do I want this one or do I want that one?

Darren Evans:

yeah, um I've seen that that's what that grass can really do yeah, yeah it is.

Nia Bell:

It's to support that kind of decision making because, yes, if you want to make decisions, you need to be able to process a lot of information, uh, quite quickly yeah, yeah, yeah.

Darren Evans:

that's awesome, and are you involved in that?

Nia Bell:

We're developing a response to that consultation. We're happy to see it come out, because I think quite a good role for the regulatory space is to provide these guardrails of regulatory space, is to provide these guardrails, um sort of the. You know the basic foundations then, which the industry can just like leapfrog that bit and then move on to the implementation and action part, which is probably more pressing.

Darren Evans:

Another stat for you Google searches have increased by 62% around asking this question what is embodied carbon? Now, how would you answer that question what is embodied carbon?

Nia Bell:

Yeah, since when that? That's quite good. Does that mean there's more people caring about it?

Darren Evans:

people are asking the question. Well, more people don't understand it.

Nia Bell:

Yeah, impenetrable lingo, yeah, um your concrete delivered on site. It's all the emissions that happened. Upstream is the lingo term before, before it arrived effectively. So that's primarily, as we touched on at the start, from the cement production that includes transport. It includes the mining and processing of the aggregates and other components as well.

Darren Evans:

And so how can people affect embodied carbon? How can they reduce their embodied carbon?

Nia Bell:

so the I suppose the embodied carbon that they are responsible for um hierarchies. So we're focused on reducing that embodied carbon of the material. But we really believe that you should only be looking at that once you've ruled out not using concrete at all in the first place. And then, once you've realised yes, concrete is the right material for this application, to first look at making sure you're using the right concrete. By that I mean making sure it's not too strong or you haven't over-designed it and added lots of fancy things that aren't really justified or needed for the use of the concrete, and you should try to be smart with the design of the material. And once you've done all of that and you still have to use concrete, then you look to reduce the embodied carbon by finding the supply chain with the lowest associated emissions. So some kilns might be more efficient than the others. Sometimes you don't have to transport the aggregate as far the rocks, and that makes a big difference to the transport mission.

Darren Evans:

And how would I be able to find that out? The supply chains?

Nia Bell:

Yeah, it's an evolving area, so data availability in this space is improving.

Darren Evans:

it's hard but where would I even start, though, if I, if I wanted to find out now. Is there a website that I can go to? Is there something that I can phone? Is there a hotline? Where do I even start? There are databases no, no.

Nia Bell:

Where do I get the?

Darren Evans:

database from, though do I can I just put that in Google Tell me the supply chain of this?

Nia Bell:

For the concrete you order. Yeah yeah, your supplier will know where they got all the constituents from. So the concrete sector in the UK is particularly vertically integrated, so they know a lot about where all the materials come from. Um, in terms of the environmental data, um, they issue uh certificates called environmental product declarations or epds, which are calculated or derived from life cycle analysis, life cycle assessment, lca second one life cycle assessment.

Nia Bell:

That's the one, yeah, that's the one, and they are a big piece of work. They involve not only modelling the carbon impacts but all the other environmental impacts of the entire process, and that includes the embodied carbon, the upstream portion, but also covers the in, use and end of life maze. It's a big and cost of developing these in is a barrier to their availability and there is work undergoing to streamline the development of these data sets. For a little sense, there is in the UK the MPA Sheet 18 Mineral Product Association. They maintain some average values for the UK industry and they put it on a fact sheet which gets updated every now and again. There was an update this year, so for a little pulse check of what the current emissions are, that's a good place to start.

Darren Evans:

And where do you see the future of this?

Nia Bell:

In terms of the data. Yeah, I would you know. Long term, there is a concept around building product passports, and to support that would be a lovely automated, digitalized system that meets the information needs of everybody, from supplier to the whole value chain, up to, potentially, the financiers and investors. That is the dream.

Darren Evans:

See, I think that that is a really quick and easy win, and I know that some people will not agree with me, but I really do think that that's a quick and easy win. And I know that some people will not agree with me, but I really do think that that's a quick and easy win.

Nia Bell:

I would say we're trying to do a little bit of that at the moment and it's not easy, but it is not easy. But I am optimistic because from the little bit we've been able to do so far and we're still working on with members we are realizing value from that data just seen as a like a, a burden, a compliance process and it's you know, tick boxes and nothing else. Just maybe you want to find the total but you don't care about how you got to that total. Um, but our experience is that if you ask the right questions, you can get some really actionable insights. Concrete Zero members commit to a target Great. One thing we have to obviously do is hold them accountable to the target, which involves reporting.

Nia Bell:

So the data element we've piloted a form for that and we've got some promising results and we're evolving it, we're trying to improve it, we're trying to push towards the more supply chain, specific EPDs where available. But we're also looking at the turning all that data into insights that can drive change. So we have members who are contractors and clients and they have visibility or has a concrete used. So that's great. Not just what concrete was used on what project, but what concrete was used on what project but what concrete was used in what element so what type of elements, so, be it a column, a wall, a slab, foundations, piles, etc.

Nia Bell:

And we can find out a lot by maybe looking across all the projects, all the data from our members, and we can see what is best practice and not only feed that back to the members but also make sure that the specifiers, so the engineers and the designers, get early sight of that market data so that they can better specify for lower carbon solutions going forward, hopefully a little virtuous positive feedback loop. So we've got early stage signs that this can not only meet our needs at Concrete Zero of holding members accountable, but can help them make better decisions around concrete. So we'll see. This is quite new for the sector and we're optimistic, but we need to see data come in. So we've had a pilot. That was great.

Darren Evans:

We need to really test this one of the reasons why in at least in my imagination, it's simple is because the blockchain technology exists now, but that hadn't existed.

Darren Evans:

It existed maybe you could say always, but it is usable now versus historically.

Darren Evans:

So put things on the blockchain.

Darren Evans:

You then have that accountability element, because you can't make a transaction without that transaction being recorded, but recorded accurately, especially when so with the sustainability consultancy that has one of the things that we've noticed that when people are doing anything relating to embodied carbon, especially lcas, because the that area is not regulated you can submit a report and if you've got a logo on there and that logo can be anything, um, it's, it's, it's taken as um, as as right and correct, but actually it's not right and correct if you do it properly, um.

Darren Evans:

And so the reason I'm saying it's easy in terms of the using the, the use of blockchain technology, you don't need an overarching body to control and you don't need an auditing process that is manual and an update that's done, that then goes into a booklet that then goes out to everyone else and they need to be trained, and so on and so on. This is just something that once you do this, then there's going to be a cascade chain reaction. That will then say, yes, we agree with what you've done, or no, we don't agree with what you've done.

Nia Bell:

Do it again yeah, I mean I feel it could be doable, but, as you so you, you know there are challenges with the EPD comparability because there's differences in the LCA modelling decisions, so that there's a challenge in that respect. I think digitalisation of the data is also still to be addressed completely.

Nia Bell:

Paper delivery notes with concrete supplies are still common practice, but I know that there's I think some academic groups who are currently looking at little bits of this, including maybe monitoring the concrete deliveries, monitoring the concrete deliveries, being able to start to feed that data into the construction sites. So I hope there'll be improvements soon and really supportive of any kind of automation kind of improvement, of any kind of automation, kind of improvement.

Nia Bell:

So I think if we, through what we still um, still um share with our members as an Excel tool, if we can just get the, the structure right, the questions um that support their decision-making, um, it would be wonderful if their technology savvy software company would like to commercialize it and please don't think let's get it right first.

Darren Evans:

So don't think that anything I'm saying is kind of criticism. You know the fact that lcas aren't done right. You know you go back to when I first set the company up, 2007. These things didn't exist back then, like no one was bothered that. The thought of an lca to be like well, I don't know that acronym, um, I don't know what you're on about or the word embodied carbon wasn't I don't even know that, that that existed, that word there. So huge progress since then. But the way that I see the combination of data and then being able to interpret that data through a filter and that to come out to mean something to someone again. Going back to the, the graph, that sliding scale from a to g or from a to whatever that you want to put it on, it just needs to be okay. I know what that is. A is at the top, it's green, it's good, it's got a plus on it and that's better than g, which is yeah a bit.

Darren Evans:

You know, I don't know, redder or a bit, a bit brown or whatever it is. There's kind of like so. So there's those two indicators there, the letters and the colors that say one is is higher than the other. But but using blockchain technology, at least in my thinking, solves a load of problems. Yeah, if anyone wants to run with that idea, they can kind of coin it as their own.

Nia Bell:

That would be a great outcome.

Darren Evans:

Good. What involvement are you having with government and lobbying and trying to make a shift and a change?

Nia Bell:

Yeah, we don't lobby as an organisation, but we do believe in bringing all the people needed to affect. You know, the pretty massive system-wide change that we need to realize together, and that includes policymakers, and quite often sort of knowledge sharing between industry players and those involved in researching and evidencing and developing policy regulations is a really important part of that. A little practical example is that a couple of years ago there was a group formed to extend the technical standards used for concrete, for concrete um, so there's a class of newer concretes using, uh, alternative binder systems they're called.

Nia Bell:

So these are ones without as much the portland cement in and they fall outside the you know the existing technical codes and in most cases um specifiers are people who decide what concrete is used Say you can use any concrete that's within code. So there was a new class of concrete that wasn't in code and some of our members joined that working group and developed with the British Standards Institute, bsi, the Flex 350 standard and that has been used now. So you know it's being used and updated and there's kind of learnings from that, I think. But you know, getting involved in you know those kind of documents, the development of the standards and the regulations and making sure that the concrete users are at the table, I think is very important. So the supply suppliers, so you, there's a whole different order of magnitude in terms of the sort of the scale and the concentration on the supply and the demand site with concrete. So there are a very small number of very large international concrete suppliers and cement suppliers, whereas even the largest contractors and engineering firms in the world are quite small compared to them. So you really need to bring those demand-side players together and make sure because we aren't a lobbyist but we do want to make sure that they, not us ideally it's the corporates themselves that join these conversations with their expertise and make sure it reflects what they need, not just what the supply side need.

Nia Bell:

We're coming up to our third year anniversary and Canary Wharf Group was one of the founding members three years ago and we had the launch event in their nice swanky offices.

Nia Bell:

So they've been involved in a number of, you know, high-rise developments where they're really pushing the boundary in terms of using the data on live projects, which I think you know we were talking about earlier.

Nia Bell:

But it is um, not just, uh, you know, specifying mixes at the start of a project but responding to different conditions during the project to adapt those mixes and, as you adapt them, to monitor, as the project goes, how you're doing against your carbon target, um, so they they also um, use some quite fancy high-tech kind of monitoring kind of gizmos. I don't know much about that and it's really good to see and I think this is the case with quite a lot of the members. So if we have one member who works in one project team and then they go and work in another project team, you know they take that learning. So in this case, canary Wharf is the client. So on subsequent projects, you know, they know that this can be done and this is what they then require and they push it. So there's the One North Key project that is currently underway where they're further evolving some of that best practice from the earlier project.

Darren Evans:

So that's what a client can possibly do is, yeah, you know, demand more, demand better and if you ask for the data, make sure it's used and I think I know where that project is and there's a lot of concrete there yeah, again, I wouldn't know how much concrete um.

Nia Bell:

Coming here today I was like maybe I need a stat about how much concrete. Would you like to guess how much concrete's in the shard according to?

Darren Evans:

google in the shard.

Nia Bell:

According to google idea 20 000, 50 000 or 100 000 sorry, just give me that number again 2050 or 100 000 meter cubed I go for us, I go for the top one.

Nia Bell:

No, it's 50, supposedly 54 thousand meter cubed, which is about 7 000 concrete delivery trucks okay I think that's quite a lot, but it's. It's really. It's really hard to get your head in on Friday. So maybe it's not a lot. It seems a lot. That's a lot of trucks. Once you work in this space, when you're cycling around London, you're like, oh, another cement mix. Oh, another cement mix, it's a lot of construction.

Darren Evans:

It's a huge amount and I'm just wondering now. This is a really daft question, so excuse the really daft question what did the egyptians do? These pyramids have been up long, long, long time I don't know how did they create the base? I appreciate they've got sand, they've got that in abundance, but you need other elements to to bind it and to bond it together. So what was?

Nia Bell:

I don't know much about the egyptians, but I I quite often see reference to the roman mortars okay, great so pantheon, you know still standing the mortars used um and you know, I think, material scientists are still looking at.

Darren Evans:

You know the chemistries and so do they not know what they're? In no, they do, they do okay, stick it my different microscopes right yeah, so so what was used then? Um, I I don't know, but yeah it's um, because these buildings back then were built to last yeah when they, when they built it, it was predominantly to satisfy someone's ego yeah and that ego was to last as long as possible.

Darren Evans:

Right, but but? But when we, when we build now, it, it doesn't. It doesn't feel that same way. When I look at buildings that were built in the 70s, it screams to me this was built in the 70s, this is dated. But when I look at something that was no, it was built in the 70s, it's dated. Maybe we need to retrofit this or pull it down. Something needs to change. It doesn't quite sit.

Nia Bell:

When I look at something which is significantly older, I look at it and go, wow, that looks beautiful I don't know why that is because, yeah, I, you know, I think it's natural, right or it's something wrong with us generally. But then once it gets to a certain age, then it it just seems, oh, it's just old, and then it's okay. So there's obviously this kind of interim period where we think we need to improve it. But once it gets too old, then we say no, no, no, we should never, ever touch it again.

Darren Evans:

I don't know no-transcript to the way that we think.

Darren Evans:

So the thinking here is linear, right, we start here cradle to graze as opposed to cradle to cradle, or some people will use the phrase cradle to gate.

Darren Evans:

So how can we get to a point where, no matter how much cement is used, no matter how much embodied carbon is there, actually, when we think about it, over the life cycle of the building, which is for hundreds of years, it really is not too much of an issue, because we know that kind of touching a thousand years, this thing is still going to be really serving the people it was designed to. To serve as opposed to. Yeah, we're given the building a um, a life cycle of 60 years, which I think is a like, it's not even the lifetime of a human. You know, maybe back in the 1920s, 1930s, maybe a little bit, maybe in the 1800s, definitely in the 1800s that was, that was a grand old age. But now if someone you know, you read on the paper, on the news or whatever they pass away it, cities like oh they're, they're pretty young, 60s, not that long no, you see buildings getting pulled down before that, which is, yeah, it's a shame, and yeah, no, yeah, ideally we should be looking for that kind of longer term thinking.

Nia Bell:

Not because um yeah, the the waste associated with demolishing buildings is another, you know, huge challenge that I suppose if I sit in the bucket of embodied carbon, I probably I'm going to just leave that somebody else to deal with but, it still needs dealing with.

Darren Evans:

Because when I, when I think about all of this together, I think that actually waste is a better word than embodied carbon or net zero or anything else like that, because effectively, what we're saying is it's taken a lot of energy to create this thing and this thing. That's been created so it can be cement, it could be concrete, could be whatever. It is a building this, so I'll use the word this thing um, all that effort and all that energy has gone into creating this thing. Yeah, then it's going to be wasted. It's not going to last for that long. And if I break that down to something that I know anyone can understand is if I go to the back door of a restaurant and I see loads and loads of food being thrown in the bin or being recycled or whatever, my heart's going to sink. I'm not going to think, yes, look at all of that that's going to be recycled. I'm not going to think that way. I'm going to be like why did they use? Why are they wasting? So?

Darren Evans:

so to me it it seems like a waste issue yeah although it's framed as net zero, net carbon yeah, I don't yeah sorry, zero carbon net zero yeah.

Nia Bell:

So the way we we might respond to food waste, I don't think naturally translates for most people into construction waste, because it's an inert material. It looks like rocks. However, the energy loss it represents is phenomenal. So, yeah, making that connection clearer could be quite powerful. But then do they have the ability to change, or make you know, change it in their everyday lives? It's difficult, though. In the construction sector you do have more of a remit to do that in in lots, in lots of ways. So, yeah, I think it's potentially quite an exciting space to be in I think so and I think that, um, I think any waste really.

Darren Evans:

I'm just thinking of a situation where I see something being wasted and I feel really excited and really happy by that, and I can't think of one no whether that's food or materials or my time or no, no, so it's more, just uh being, yeah, in a waste of a resource. Just, I don't know of anyone that's like, yes, look at all this waste the outer sight, outer mind.

Nia Bell:

The waste sector is very efficient. That's okay getting it. You see the barges going down the Thames. Don't ask what, they are, just taking the waste out. But yeah, it's really interesting.

Darren Evans:

I think that the thing, though, in that is making it understandable, tangible and accessible to people yeah because at the moment there's lots of data points yeah lca, embodied carbon, all of these different things, various certificates, various different yeah programs how can this be bundled together to create something which, just at a glance, I can say okay, yeah yeah, well, there are.

Nia Bell:

There are potential shortcuts. The data can be um. It's a great thing, but it can also get in the way. For example, the most carbon intensive cement product is called sem1. So if you ask for concrete with without sem1, so you say I want something other than sem1, then that will mean um, you get a lower carbon concrete. So these are some two, some three, some four, and the higher numbers generally indicate more of the lower carbon uh. Substitute materials have been added. So you know there is sort of shortcuts. It or even just asking the question what cement is in this product, why? That can also show who you're asking that. This is something that you're thinking about and they need to get a good answer for it.

Darren Evans:

So as an example, then we could, if I was, was a developer, I could say we no longer build with someone.

Nia Bell:

Yeah, that would be a great way to so that is the approach some, some are taking, um, and I think it's kind of a like there's a carrot and stick, so sometimes you need to just say no to cut off maybe that tail of lower performing products, um. But I think what's probably more exciting is how can you incentivize and be supportive of the really groundbreaking. So let's forget standard, you know, putting some slag, putting some flash. Let's think about the really new to market products that we want to see grow, and that isn't necessarily going to happen organically. That needs strong demand signal and it needs support from the demand side, from the demand side and also maybe from the finance industry to identify and develop these kind of innovative materials.

Nia Bell:

There's an interesting project that is called the Advanced Market Commitment. It is Google-able, they have a website they're not quite live yet but they're in sort of pre-launch and it's all about the demand side, um, specifically committing to procuring some of these innovative low carbon materials. So it's more than just saying we commit to getting below a target. It's actually committing to using, if they're brought to market, these products, which then gives the investors confidence to invest in the scaling to meet the demand. So I think it's a really exciting project that's coming online and could be that carrot, that way of growing and pushing forward on those really, really low-carbon materials.

Darren Evans:

I'm wondering what lessons can be learned from other industries.

Nia Bell:

Well, that particular project, that particular project is using a template developed for the covid vaccines. So when the covid vaccines needed to be developed, um, the government in this case, agreed to buy them before they were even available okay so it's that kind of mechanism which then allowed the you know, the scaling and deployment of an insane a number of vaccines in a short period of time. So it's, I think that's very interesting yeah, interesting.

Darren Evans:

The one that was in my mind, though that is a good one. The one that was in my mind is there's been a huge rise of chat GBT. There was a massive take of users in Facebook felt like it happened overnight, but in both instances it didn't. It started with a small group. It was very targeted. Then it went to a larger group. That was very targeted. Then it went to a larger group.

Darren Evans:

That was very targeted, before it went to a larger group yeah and then the fourth stage was okay, this is now open to everybody. But that last stage the that there's a number of people that knew about it and wanted to get involved, but they felt that, well, they weren't able to to gain access because it was just for, okay, a group of people.

Nia Bell:

So that's obviously in the tech space, not in the construction space um, I don't think we want to be putting up any artificial barriers to getting involved in these type of mechanism.

Nia Bell:

All concrete, zero so we are open if you, if you're involved on the demand side, it's it's not an exclusive club um at all. So it's it's all about knowledge sharing, um, pushing best practice, uh, changing the narrative of what can be done now, normalizing it, all of that. So, yeah, I think that it will. You know there will be leaders. I'm very happy to get to work with a lot of them, so that's excellent, um. But yeah, I don't think we want to be putting up barriers to anyone who wants to do anything. So it's, there's no silver bullet with cement and concrete. It's going to take everything and every. You know everybody. So the supply side can't fix it by themselves. The demand side will need to use lots and lots of little levers. You know, over and over again, micro improvements. Sometimes you'll get changes, but it will be this continual optimization process that gets us where we need to be.

Darren Evans:

It's been great having you on the podcast today. I've enjoyed your passion and enjoyed the opportunity to talk to you about concrete and about embodied carbon. I am just wondering here, just as a last parting question, what message you have for the listeners and for the audience that has that would further help you, your cause and what you're trying to achieve.

Nia Bell:

I'd say just find out, educate yourself a little bit more about concrete and don't get put off by the technical content. If you like that kind of thing, there's plenty of it, but I'd say not to be put off by it. And yeah, just look around while you go out and about um, and once you start looking for it, you can't get away from stuff unless you go very far, deep into the mountains. Um, no, but um, we are a young initiative. Three years in, we feel that we're doing good in the market. We're responding to a market needs. We're complementing the strengths and technical expertise of our membership, layering on something a little different.

Nia Bell:

Um, we're open to keep exploring this, getting feedback. There's so much to do. Prioritizing is our main concern. There's different markets, there's different levers, there's different ways we can be supporting our members. So, yeah, talk to us, I'd say, is the most useful thing. Talk to us, I'd say, is the most useful thing, because there's an example where one of our members married um like efficiency, so material efficiency yeah you know whether and how you use concrete.

Nia Bell:

With the material intensity bit, you know what concrete you use and getting that as low as possible. It was an example. It was. It was an example in the bristol university development that happened last year. Okay, um, and it involved actually an engineering members, so barra haphold, as well as a contractor, sir robert mcalpine, and they were, and it is quite often the case. So they want, you know, they were challenged to reduce the cost of the build and it was quite a challenging site.

Nia Bell:

And then both by effectively cutting the amount of concrete, so reducing the amount of concrete used in the structure, as well as early engagement with the supplier.

Nia Bell:

So if they had, just on the first day of the builds, asked the supplier, what have you got for us, their options would have been much more limited.

Nia Bell:

But by going to the supplier a few months in advance and saying, look, we're going to be needing all this concrete in three months, can you give us a silo of this lower carbon material? That opened up an opportunity. So for that particular project, they cut the emissions by a quarter, which is a lot. So those things I think really, you know, being able to put a number on. It makes it seem a bit more, hopefully, worthwhile for others to maybe look at and it's actually one of the slightly positive things we can say about concrete. You know, tackling emissions and concrete at the moment is that it doesn't always come with a price premium and this that is different to steel and other materials. So it's not always the case and when you are pushing the boundary and trying to, you know, scale, new technologies there will be, maybe that there will be sort of implications there, but for some of the off-the-shelf lower carbon materials the price premium is, you know, okay.

Darren Evans:

And this, what you're talking about here, is really easy done. It's really easily achieved.

Nia Bell:

I couldn't do it, but maybe you know a power powerhouse of an engineering consultancy and a leading contractor put their brains together but I don't know.

Darren Evans:

I think, you see, because you know all you need to do is come together early and just communicate that out early, that that concept is simple, that concept isn't going to cost you any more money, it's not going to cost you any more time. I think, in fact, it's going to save you time because you're coming in at an earlier stage to say, giving your heads up, this is what's going to be coming in the future. Can you start the process rolling there for me? And I'm guessing here that they didn't commit strongly as in pay a significant amount of money beforehand, so it didn't did that upset their cash flow in any way, shape or form I don't think that would have been needed.

Nia Bell:

Um, no, no, I. I don't know the exact commercials of the arrangement, but I think there was a commitment to maybe introduce 35% of these lower carbon materials and they actually beat that target in the end. Another practical way people sort of start to look into this is, yes, it's early engagement with suppliers, but also um, to get kind of pre-approval on a suite of mixes. So instead of just having maybe three or four mixes approved by the um engineer at the start of the project, if you have more, then you can. You know you can use them differently and there's a lot more optimisation you can do across the lifetime of the project.

Darren Evans:

So how would that work then, to get multiple mixes approved at the early stage?

Nia Bell:

Yeah, so there's a sort of a process when it comes to making decisions around what concrete use. It's called a specification process. We've put out a bit of a guidance on that. So earlier this year there's um quite a lengthy document on our website, but it's got some good pictures in it.

Nia Bell:

One which I think is quite a useful resource to explore is a matrix, if you like matrices.

Nia Bell:

It's got the different construction stages across the top and it's got the different construction stages across the top and it's got the different roles in a construction project down this side and basically it shows what you can be doing depending on your role and where you're at in the build how you can be questioning, influencing, checking, driving the specification of lower carbon concrete, because traditionally it's been quite linear the engineer specifies the uh, the contractor you know designs the mix, the supplier provides it provides you know the mix and the engineer checks it and that's it.

Nia Bell:

But you know if you really want to unlock the expertise of all of those involved, because ultimately the choices on what concrete use isn't all about how strong you need it to be at the end. There are a lot of other factors um around the construction process come into play and you know, if you're not, you're never going to know that unless you ask the people doing the construction. For example, maybe you don't need the early strength game, maybe they can leave that to cure and do something else in the meantime. You know there's lots of, lots of things and if you don't ask you won't know effectively the other thing is you don't ask, you don't get I wasn't going to say that possibly you don't get.

Nia Bell:

Well, if you don't, you don't know what's possible.

Darren Evans:

Yeah, exactly right, exactly right. And I think just asking that and starting that conversation early, that's just one of the things I'm just a really big advocate for. There's so many good things that happen when you plan early and ask early and just get things done early, even waking up early.

Nia Bell:

So many good things, yeah you're not gonna get me on that but just early engagement is.

Darren Evans:

It just leads to so many good advantages. But just doing things late or when you just need it to be done, or before or just before it needs to be done, it's just you've just lost all your wiggle room yeah, anyway, so hopefully, um, maybe we can put it in the comments or something, but that's quite a useful document yeah, give it. Giving us that, yeah, you can give us, you can give us access to that, can't you?

Nia Bell:

yeah, it's all on our website. We brought a few few of these things.

Darren Evans:

Yeah, that'd be good. Good, definitely, getting up early is good though.

Nia Bell:

Yeah.

Darren Evans:

It's been great having you on the podcast.

Nia Bell:

No problem, darren. Thanks very much, cheers.

Darren Evans:

Thanks for watching to the end. I think that you'll like this. But before you do that, but before you do that, just make sure that you've commented and liked below and also that you've subscribed.