How to reduce carbon emissions in the construction sector

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This video is a direct recording of the webinar, which includes footage of the speakers as they talk. There are also some slides provided by the represented companies interspersed throughout this webinar.

Audio - Gordon Harcourt

Tēnā koutou, tēnā koutou katoa. Nau mai, nau mai haere mai ko Gordon Harcourt ahau. Kia ora, welcome, I'm Gordon Harcourt. I'm the communications lead for the Construction Sector Accord. Welcome to this, the latest in a series of webinars towards higher performance.

Now the Accord of course, is a partnership between government and industry trying to fix the many challenges our sector faces today. Carbon emissions in construction, how do we reduce them? Our industry of course, is a major contributor to carbon emissions from producing materials, constructing buildings, the energy that those buildings use. So, we do need to play a major part if New Zealand is to reach its climate change goals, including of course a net zero carbon by 2050.

Today, we want to give you a real practical advice on reducing carbon emissions in construction and we've got a really substantial lineup of speakers for you from the Accord, from the Government's Building for Climate Change Programme, Jasmax, Warren and Mahoney Architects, Holmes Consulting and Naylor Love.

First up today, Richard Stone. My colleague at the Accord is currently the Accord's Acting Director for Construction Procurement Transformation, and he oversaw the writing of this document, the guide reducing carbon emissions in building and construction. Kia ora, Richard, welcome.

Audio - Richard Stone

Thank you, Gordon. I'm here to talk briefly about the New Zealand government's recently launched procurement guide to reducing carbon emissions in building and construction. The guide follows direction from government last year that the procurement of government buildings should lead the way in accelerating change towards a net zero carbon construction sector.

The guide offers practical guidance and tips to those involved in procuring construction work to think about how they can influence positive change through the procurement process and is primarily focused on the planning and design phase where most of the key decisions that have the biggest impact on carbon emissions are made. You may or may not be aware that the Building for Climate Change Programme is already considering regulating carbon through the building consent process. So, the guide can help those in the sector that are less familiar in this space to develop their capabilities and be better prepared for potential changes. The guide is part of the New Zealand government's construction procurement guidelines agencies that are mandated under the government procurement roles are required to apply the guides for new construction works with an estimated value of $9 million or more.

This particular guide requires a three-step approach to be taken by agencies during the design process, which includes developing a carbon brief, assessing the relative carbon impacts of different design options that are being considered and reporting on the decisions made during the design process. The template carbon brief is also provided for those less familiar in this space to set out the key focus areas of a building project to reduce carbon and also to out the reporting and assessing requirements of the design team. Chief executive sign-off is required, if a government agency decides to proceed with a design option, that is not the lowest carbon option, all things considered when looking at the project brief.

But enough about the guide, we have some fantastic speakers lined up today to share their experiences and views on how we can successfully work together to reduce carbon. For example, we have Katie Symons from MB, who'll talk about her work on the building for climate change programme and the really interesting areas that they're focusing on. We'll have Chris Scott of Jasmax, he'll share his thoughts on how we might need to think differently about design in terms of how we might repurpose existing assets. We have Graham Finlay of Warren and Mahoney who will talk to us about their bold move to publish carbon targets on their website. And talk more about how they're actually going to achieve that. And then Lisa Holmes of Holmes Consulting, talk about how engineers can influence change through approaches to the structural design and last but not least Naylor Love to talk about their carbon calculator and some of the reasons that they took on developing this.

The guide is a great step forward, but for the Accord, the real value is in the collaboration and sharing of ideas across the sector so that we can make a real difference. I hope you enjoy the webinar today.

Audio - Gordon Harcourt

Thanks so much. That really sets the scene for today. Next up, Katie Symons from the Governance's Building for Climate Change Programme. Kia ora, Katie.

Audio - Katie Symons

Thank you very much for having me.

Audio - Gordon Harcourt

So, Katie, the Building for Climate Change Programme aiming to drive transformational change in the sector to meet the challenges posed by climate change and to meet the government's target of being a net zero emission nation by 2050. First off, what role do you think this document, the guide to reducing carbon emissions in building and construction, what role can these guidelines play in reducing carbon emissions in the sector?

Audio - Katie Symons

So, there's new procurement guidelines from government property group are really, really great, and they were really good tool for a bit of a comment change programme in terms of our government leading the way ideas.

The idea is that we're going to be bringing in these changes to encourage change of behaviour that reduce emissions, both operational and embodied emissions from buildings. And these procurement guidelines are a really good signal that public sector buildings will be adopting these changes first earlier, and demonstrating to the rest of the sector, how these changes can be achieved. So it's a really good way to demonstrate to the rest of the sector that these changes are possible.

Audio - Gordon Harcourt

So, you are part of course, of the building for change programme. What are some of the key initiatives?

Audio - Katie Symons

In the two frameworks that we published in 2020 that looked at separately how to reduce operational emissions, that emissions from heating, cooling, lighting a building, and embodied emissions there, the emissions to do with the stuff that the physical materials and products in a building, we had those two frameworks to address those two types of emissions. Really the headline of those frameworks is that the proposals are that in order to get a building consent, you will have to have thought about those emissions.

Initially you have to declare what those emissions will be for new buildings, so what the operational emissions will be every year of operation and what the embodied emissions will be over the whole life. So initially there's just a mandatory disclosure phase where you just have to say what those emissions will be for the new building, but eventually we'll be bringing in caps, the proposals are to bring in caps so that in order to get a building consent, those two types of emissions you'll have to come below a cap that will be set and then over time.

Those caps will gradually decrease in line with our requirements to reduce emissions across the building and construction sector in line with the requirements to reduce emissions across the New Zealand economy to be zero carbon by 2050.

Audio - Gordon Harcourt

One of the things you focused on is increased carbon literacy. Can you tell us more about that?

Audio - Katie Symons

Sure. How I like to describe carbon literacy is having a gut feeling for what the carbon emissions associated with a building or what they are both those embodied and operational emissions. And that's particularly is a bit more challenging from embodied emissions because those emissions that they're kind of, "You might call them hidden." You don't see those emissions when you buy your steel, your concrete, your timber, they happen further up the supply chain, but nevertheless they've happened and they've occurred, and if we want to reduce them, we need to be more familiar and get used to thinking about what those emissions are and estimating them just in the same way that everybody who's involved in a new building needs to think about the cost of that building in dollars.

What carbon literacy is, is people being able to have a gut feeling for, as well as what the cost of something is, what the carbon emissions associated with that thing is. And really, it's about everybody involved in designing, procuring, building a new building, being able to quantify that impact in terms of carbon, they might quantify their impact in terms of cost, and how they think about that in decision that they make in their work to make that new building happen.

So, whether it's a design decision, what kind of material you're using or how you might build it or manage the construction on site just thinking about the emissions associated with the options as you make those decisions.

Audio - Gordon Harcourt

Carbon reduction, really the great challenge of our time, what are some of the key challenges in new solutions on new technologies? What can the industry do to support change?

Audio - Katie Symons

To reduce emissions across all areas of the economy to the extent that we need to, to become zero carbon by 2050, will require big changes. So, let's not kind of shy away from that, but perhaps some of the solutions, they might not be new. It might not be new technology. It might just be doing things differently to the way that we've done things before.

So, making a change is always challenging, but if we can really put carbon at the forefront of the decisions that we make and we make new buildings, procure build design new buildings, I think we might find that some of the solutions are already there. It might be using less material. It might be making use of existing buildings rather than building a new one. It might be building buildings to last longer, to be more resilient. If we put carbon in the forefront of our mind as we make those decisions, it could be that some of the solutions already be there.

And it will be challenging to change the way that we've been doing things in the past. But again, I'm going back to the procurement guidelines, having that carbon brief, if you like the idea of thinking about carbon at every stage of the new building process will help us find those solutions.

Audio - Gordon Harcourt

Thanks very much, Katie, thank you for sharing some of those key initiatives that the ability of a climate change programme is undertaking.

Next up. Chris Scott, he's Principal Architect at architecture and design from Jasmax. Kia ora, Chris, thank you for joining us.

Audio - Chris Scott

Kia ora. It's great to be here and really glad to be part of this.

Audio - Gordon Harcourt

So, carbon of course admitted right through the lifecycle of a building from construction to final disposal, you guys at Jasmax have done some research into the life cycles of your current projects. What are the findings?

Audio - Chris Scott

A year ago, when Jasmax adopted the Royal Institute of British Architects guidelines for getting our carbon emissions down to net zero carbon. We invested in better research to see where our buildings are at the moment and see this kind of where we are on the journey, but also how achievable are those goals that the British Institute of Architects has set for achieving by 2030? And we started off with five buildings. I think we looked at and we commissioned International Carbon Consultancy to do the initial carbon measurements.

We've subsequently done quite a few others as well. So built up quite a big database. But what we've found is that because in Jasmax we've been concentrating on operational energy, reducing operational energy and hence operational carbon for a long time now, we're actually getting down to some pretty low numbers in the operational side, particularly with new Zealand's low carbon electricity and what we're finding with some of our highest performing buildings and including award-winning buildings that have one sustainability at wards, the embodied carbon now makes up significantly more of the total carbon, then the operational carbon, which was quite an eye-opener actually, I mean, just given that the whole industry, industry has been so focused on the operational side and reducing energy consumption.

The fact that there's been this elephant in the room about how much carbon is emitted during the construction, the materials, and the maintenance of the building. But what was encouraging was that three of our projects have actually met those targets for 2030 as set by the British architects. And I can talk more about what's particular about what's particular those buildings as we go on.

Audio - Gordon Harcourt

We've heard the terms embodied and operational carbon a few times today. What is the difference between them in terms of the life cycle of a building?

Audio - Chris Scott

Well, that's the other huge learning actually, as we've gone on to this more and more embodied carbon being, as I said, it's the carbon from materials, construction and maintenance and the assembly at the end of life. This is the operational which is essentially the energy and water. But of course, when you look at the lifecycle of the building that embodied carbon, most of that, or a huge chunk of that happens before the buildings even occupied.

And in fact, we've analysed, I'm just done the analysis on the lifecycle carbon on a school, on a typical primary school and we can kind of show you the graphics, which has kind of similar, I guess to that the appears in the MB document, but it's even more exaggerated than that. So, 40% of the carbon emissions, they're up in the atmosphere before the buildings occupied on that project.

We also did some optioning on that, and we can reduce that down to a kind of 30, 35% without too much work, whereas the rest of the carbon, that other 60% that spread over the other 60 years of a building's life. So, and of course that will reduce sometimes. So, the operational carbon and the maintenance carbon, presumably over the next 60 years, we're going to get better at reducing the carbon content of energy water and the materials that go into maintenance. So, in fact, that 40% initial figure, which is huge anyway, but that's like, could he be in reality a much higher percentage of the title carbon emissions and we can't do anything about that. It's already up in the atmosphere.

Audio - Gordon Harcourt

What are the key principles incorporated into your lowest carbon buildings?

Audio - Chris Scott

If we take the three current projects, that's ones just recently being completed and a couple under construction at the moment, they all have common elements. If you like that enable them to meet those net zero carbon targets. So, first of all, incorporate an element of re-use of the existing, I guess the first principle, probably the biggest principle in terms of reducing carbon is to build less. So, one of the ways we can do that is to use elements of existing buildings rather than demolish the whole building. And so, these three projects, they incorporate an element of a distinct building in quite different ways. And I can talk about that further.

The second principle is to reduce by building lists, seeing principles, what we do build is then to build with lower carbon materials. And again, this kind of means thinking about the project right at the start. And often that's just simple material selection, but it's also how we build and these three projects, there were elements about how we built that responded to the particular requirements of the site, so that they were economic as well as carbon decisions.

The next one is probably just incorporating as many carbon sequestering or low, carbon materials into the building as possible, right through to the end. So, there's an awful lot in the detail that actually makes the difference. So, it's not just about the structural system. In fact, it's very, really just about the structural system, because I think every building has competent structural systems to some degree anyway. So that's also about things like carpet materials finishes right through the building and actually the furniture and everything that goes into the building makes a massive difference as well.

Audio - Gordon Harcourt

You just mentioned using existing buildings, otherwise known as adaptive re-use. Tell us more about that.

Audio - Chris Scott

Well, it's very simple to reduce carbon. We need to build this, that's by far the most effective way of reducing carbon. And that does mean reusing existing buildings, it means retaining heritage buildings, but what we're doing is actually something different. So, the adaptive re-use we're doing is actually reusing building components.

And if you look at those three projects, it's a building for Canterbury University, the Beatrice Tinsley Building where a building was demolished after the earthquake down to its foundations, but by putting a lightweight timber structure building on top of that, we were able to keep all those existing concrete foundations, so we didn't have to rebuild those. So, there's a massive carbon saving there coupled with the low carbon timber structure.

The second project is the project we're doing for AUT university on the North Shore. And again, that one couples your timber structured element on a raft foundation and that's timber structure because we had to build really light because it's poor soil and that enabled us to build more by keeping the weight down, but that's joined to an existing four-story building with a new timber atrium and that existing building, which would be a staged development. So, we basically completely refurbishing that building, so we're gutting it. We're redoing the glazing eventually that will be completely re-cleared and tightly sealed high-performance facade. But it's a combination of those two that actually gives us a low carbon result.

So that adaptive re-use of the existing building with a new building of about the same area or the third projects, even more dramatic, which is the what's known as the B201 building for Orkin university, which is the old human sciences building. Now this is a 20,000 square metre building 50 years old at the end of life. Everything about it was that the end of life, except for the concrete structure, which we're able to give another 50 years basically by taking the weight off it currently, not performing that well, so clear because of the very heavy cleaning, but by lightening that building, we can get that structure another 50 years. And that enables us to put a new lightweight facade, new interior, add on extra area.

So, a benefit there and kind of avoiding a year of demolition destruction, but saving and carbon of having that existing concrete frame and concrete floors, that's huge, that's 50% reduction in carbon on that project and effectively getting a new building at the end of it, which is a state of the art for purpose, a high or low energy consumption, high energy performance. So, it's kind of no negatives in terms of that result. 10 years ago, we probably would have demolished that building, but just thinking about building lists changes the way we think about these projects.

Audio - Gordon Harcourt

Last thing. What are your key learnings, your takeaways from these projects?

Audio - Chris Scott

Yeah, very much so. So, we've been surprised often at where the carbon is actually. So, those key learnings about using carbon-sequestering materials such as timber and adaptive use, those are the easy ones in a way, but what we've discovered is that actually goes all the way through the process. And I guess with those projects than other ones, it's an awful lot of the detail. And for instance, we've just done the analysis on a primary school at the moment, being built for the ministry of education and we looked at carbon reduction at three levels. So, the first way we looked at it was, What's the easy carbon reducing, what's the low hanging fruit without changing the way we build that building?

So, it's basically just materials, substitution, or just changing the specifications. And just doing that enabled us to take, I think about a 20% reduction in the carbon on that building. And then we took it to the next level and looked at it. Can we do a kind of competent steel and timber structure?
And then we looked at, can we do timber floors? And by doing all those things, so that's, I guess, material substitution, the first one, the easy one, change the structural system, look at how can reduce the carbon there and then to get more innovative, I guess those are the three ways we looked at it, but just the gains in that material substitution are huge. And I think we really need to look at that really carefully because that's a matter of making carbon part of the brief right at the start. And then that helps you select the right carpet, just slipping, right?

Carpet can make a massive difference. Selecting the materials all the way through using say, timber LVL purlins rather than your traditional steel DHS purlins. It's really just a light for light substitution. There's usually a small cost impact to these decisions, which is why carbon isn't a part of the brief if you just go for the cheapest price, you won't get there, you've got to make carbon equal emphasis to the cost or part of the criteria along with cost and do that right from the start.

Audio - Gordon Harcourt

Thank you Chris. Some real practical stuff there for the industry on making a carbon emission reduction part of that design phase.

Next up. Graeme Finlay, Chairman and Director of Warren and Mahoney Architects. Kia ora, Graeme. Thank you for joining us.

Audio - Graeme Finlay

Thanks very much for inviting me. I'm very pleased to be here to be able to join in this discussion.

Audio - Gordon Harcourt

So, Graeme, Warren and Mahoney, you've set some big goals on climate change, carbon reduction. What are they and why?

Audio - Graeme Finlay

Yeah, it's always been something that's been on the radar for us. So, we've been carbon neutral as an organisation for actually the last 14 years. So, it is part of who we are, but as designers, we need to be future-focused. We need to be looking at what's happening in the world and what's happening in the market to advise our clients properly. And we have over recent the last year or so, we've been talking with an awful lot of our clients about sustainability and what it means for them. And there's been, I have to say a really significant shift between how they would have responded to these things maybe two years ago and how they're responding now.

So, now the discussion is really about sustainability being a business imperative as opposed to before it might've been social corporate responsibility or something of that nature. So, there's been a very, very big shift in our market. We also feel a responsibility. We are the largest architectural practise in New Zealand and one of the largest in Australasia. Pre-COVID I think our designs to deliver it about $800 million worth of construction across sites in New Zealand and Australia and elsewhere. So, we do feel we have a responsibility to be part of the solution as opposed to problem. And so, I guess a lot of other organisations, we feel it's really important to have clarity, to give clarity and make a statement that gives clarity for our future decision-making, but also to guide our staff. The big surprise for us is what’s happened since we set this.

So, we set this goal maybe about 12 months ago, in the last two years, but really in the last six months, government's representing about 70% of the global economy have signed up for carbon neutrality by 2050 and in the case of China, 2060. So, there's been this enormous shift and I think we all need to recognise this scale of this commitment, we're about to hear a lot more about it as we go to the rerun of the Paris Accord in November, which is going to be in Glasgow I think, where there's the reestablishment of the next 10 years targets for all of these countries. But when we just drill down what carbon neutrality by 2050 means for 70% of the global economy, it really is enormous. So, what it drills down to that is in the next 30 years, there's going to be a redesigning of our energy production systems and supply systems of the transport systems, of the manufacturing systems, of the energy using appliances we use, the way we design our homes and the way we design our building. So, this is gonna be happening across the globe.

So, for us looking at this and seeing what's happening internationally now, it's clear there is an enormous commercial opportunity for business and I'm not sure people really understand that yet. It's also clear that there's a risk for us as designers and for building developers and building owners that they need to be anticipating and understanding the scale and pace of change ahead. So, we need to be thinking when we're designing a building today about how that building will be received, what is completed, but not just when it's completed, in five years after it's been completed, 10 years after it's completed, or 15 years when the world will actually be halfway through its journey to carbon neutrality. So, that's really, I guess, where we're coming from and what we've been learning and seeing in the market.

Audio - Gordon Harcourt

Graeme, one of the goals is for the new projects to be net zero carbon by 2030 plus 50% more energy efficient, 40% less embodied carbon. How are you doing this? What are the challenges?

Audio - Graeme Finlay

When we set the goals, we actually believe that probably a possible, since we've seen the political change globally, we're feeling a bit more confident because we think the landscape has changed dramatically and our goals are really what everyone's going to have to achieve. What are the key challenges for us? We can't do any of this on our own. We have to work with our clients, the other consultants and the contractors that we work with. Everybody's got to be on the same journey to achieve it. And that really goes to, I guess the next challenge for us is we have learned that almost everything in this sphere of sustainability is actually a people challenge not a technology challenge. It's about getting people on board. And one of those people issues is the fear of not being perfect.

And I think that's been one of the greatest barriers to organisations and people starting on a journey to improving their energy efficiency or anything is the fear that they won't be perfect. And when it comes to the environment, I don't think we can allow that to be a barrier. We just have to accept that we're taking a step that will be imperfect and we're on a journey and we're learning on way. And then finally, the challenge for us is probably the type of buildings that we're working on. It's all very well going for carbon neutrality for a house or a community centre or something of that nature and scale but aiming for carbon neutrality in a half a billion dollar hospital or research centre is a very, very different beast and a very, very different challenge.

So, I mean, our challenge is to get there. So, the buildings we're designing in 10 years, we'll meet these targets. We do hope we're going to have other buildings which will exceed these targets on the way and generally as things change in design, there are the four runners and there is the mainstream follows.

Audio - Gordon Harcourt

As a firm, you've recently launched a three-year PhD study to produce a framework for reducing carbon emissions in building design. Tell me about that.

Audio - Graeme Finlay

Yeah. Look, there's this thing about the data being available for us to use and the knowledge being available in the industry is really the first thing we hit. Once we set these goals for ourselves, we realised that actually we have to be involved in helping some of their search happened. Well, the process has been a total eye-opener for us. So, we're working with Victoria University, it's being sponsored by Callahan Innovation. It's being conjunction with brands. And actually, it's been amazing. And we are looking at this and thinking, how can we extend this research programme, because we're finding the benefits already within six months from it.

So, we have a PhD student who's working at the moment. They've got a three-year programme, and there's certain deliverables along the way. These are the first ones identifying and assessing the best sources for data about embodied energy for us to use in New Zealand and our buildings. That's really number one. The next one is reviewing of the embodied carbon design and many measurement tools, which are out there to try and find what are the best tools for designers to use at different stages of the design process.

The next one is reviewing a number of our projects and then working with our project teams to uncover the lessons learned. So, this is sort of the brutal truth of what we're doing right now. We're not pretending we're perfect. We are just learning. And then it's creating really a set of tools to guide designers at different stages, at what stages are the key designs being made, which will affect the embodied energy. And so, these are the things in this information, as it comes out we want to share with the industry. We do think that's really important. And so really that's the focus of, I think we're involved in a little piece. There is a lot of research that is required in this space, both in New Zealand and internationally.

Audio - Gordon Harcourt

Okay. What advice have you got for others in the industry trying to reduce carbon, any helpful tools that you would recommend?

Audio - Graeme Finlay

Yeah, well, I mean, the first one is just start measuring or try to measure what your buildings are using or your operation is using, because the minute you do that, it just opens up a whole world and don't be frightened that what you see doesn't make you happy, but just understand that you have to start measuring, we've got to lift that lead, and once you left that lead, you cannot begin to understand the things that you can improve.

So, that's the first. I think the other is that we shouldn't hold the knowledge to ourselves. I think we need to take a leaf out of the book that we learned during COVID in the development of the vaccines, the sharing of information to accelerate the development of vaccines internationally. As I said, at the start, the speed and the scale of what needs to be done over the next 30 years shouldn't be underestimated and we need to share information so we can get rapid acceleration of knowledge and tools. So that's what I would my first two things.

In terms of tools, I mean, in terms of operational carbon, like we are advocating for neighbours and Greenstar on all our projects. Now that's part of what we're asking our staff and our project leaders to talk with clients for new projects. In fairness, a lot of that is coming from clients. Now that started projects, but those tools, they just open up a different discussion about energy efficiency and carbon use within the builder. So, immediately you make a decision to go with neighbours or go with Greenstar. You've actually opened up a world of discussion for the design team, for the client, about what they want to do. And you can start making decisions based from knowledge rather than just making decisions without realising the decisions you're making.

So, for operational carbon, it's say, use those rating tools, they'll actually change the way you think and understanding. And then 22 has worked with the green building council to develop a rating carbon zero tool and I think we should be looking at that and beginning to look at that for the operation of buildings, that's the scheme that we're certified on, neuroscience as a company. And then there's a number of tools out there for designers.

Now, a lot of them are a bit complex to use and they do need to evolve a bit, but there's a New Zealand, one brands LCAQUICK, which is a tool that can be used for embodied carbon. And then there's another one, an international one being developed called ONECLICKLCA. So, we're looking at both those tools and trialling both those tools at the moment, but it's fair to say it's different tools for different stages of the design process. So, I would say you look at those depending on where you are in the project.

Audio - Gordon Harcourt

Thank you, Graeme. We look forward to hearing more about that PhD study.

Next, Lisa Oliver, she's Project Director at Holmes Consulting. Kia ora, Lisa, thank you for joining us.

Audio - Lisa Oliver

Thank you for the opportunity. I'm looking forward to being part of this discussion.

Audio - Gordon Harcourt

So, Lisa, we've heard from the architects, now, the structural engineers on the spot, what do you think the role of structural engineers is in carbon reduction sustainable design?

Audio - Lisa Oliver

Well, obviously sustainable design needs to be something that is the whole design team works on together, because there will always be things specified by one member of the design team that might have negative impacts on the sustainable aspect from another design team member's perspective and a balance needs to be found. So sustainable structural engineers are definitely part of that collaboration process, but if you split that sustainable design into the embodied carbon and the operational carbon, then really structural engineers are most involved in the creation of the building and the embodied carbon part of that.

So as the knowledge about embodied carbon, or is it operational efficiencies recognised, and the importance of embodied carbon becomes more visible as a way to reduce the overall emissions associated with the building, then that's really an opportunity for our structural engineers to have a greater impact and sustainable design.

Of course, we also need to understand how our design decisions influence the operation of the building, considering things such as where stretching much act as a thermal bridge or alternatively, where it might provide some thermal mess, but really, it's in that calculating the embodied carbon where structural engineers have the most influence because the primary structure is a big component of that.

Audio - Gordon Harcourt

From an engineering point of view, how can we reduce embodied carbon?

Audio - Lisa Oliver

Okay. So, there are two main strategies for reducing embodied carbon, one to use less materials and two to use materials with a lower carbon intensity. So, to use less structural engineers can promote reusing existing structure through adaptive re-use, but we can also make our designs more efficient. Now, every structural engineer I know really strives for efficient designs, but with the edit driver of sustainability, perhaps we can do even more to highlight where these efficiencies can be made, say adding an extra column or a deepest structure where we can highlight to the rest of the design team that doing these things will produce an overall board materially efficient structure.

So increased collaboration with the design team as one way to design more efficiently. Other things the structural engineer can do to use less materials to increase the useful life of structures. So, considering durability, maintenance, and the resilience of the structure. So, designing the structure for potential extreme weather events or earthquakes, we can also reduce the produce the material use by minimising waste associated with the construction. So, considering how the building's going to be built during construction and potentially using things like prefabrication to reduce waste. So, the second strategy to reduce embodied carbon is to use lower carbon materials.

What I mean by this is materials that take less energy and therefore produce lists fewer emissions to produce transport construct and maintain. So, to do this, we need to understand the carbon associated with the different materials. And also, what changes will make the greatest impact. For instance, substituting a floor or foundation will have a much larger impact on the overall embodied carbon and the structure then substituting a few columns. So, we need to be thinking about using each material to its strength and not just going for the lowest carbon material by default, but as this might lead to a converse effect. So, it needs to be this balance of the lowest carbon where appropriate. So timber is a great low carbon material and can be used to create really sustainable buildings.

I love designing with timber, but there will always be a need for steel and concrete as well. And the industry is working towards lowering the embodied carbon of these other materials too, such as improving supply efficiency and making concrete mixes that use less cement.

Audio - Gordon Harcourt

You've touched on adaptive re-use. How can engineers support this, do this?

Audio - Lisa Oliver

Well, yeah, adaptive re-use is one of the top ways that we can reduce emissions contributed to the built environment. So, you might've heard people say that the most efficient building is the building you don't build. Well, adaptive re-use means that you don't need to build, or at least you build less. So, it not only stops the emissions associated with a new building, but also the emissions and waste created from when an existing building as demolished.

Another fact in favour of adaptive re-use is that most buildings that will be around in 2050 when New Zealand that is aiming to be net zero, they're already built. So, if we only concentrate on new builds, it will take a long time to impact the overall emissions. So structural engineers are key to successful adaptive re-use projects. We can assess the existing capacity of structures and look for opportunities to add more levels or open up spaces.

We can develop strengthening schemes to improve the structural performance of the existing structure, the resilience of that structure and prolong the useful life of the building. Now working with the existing structures can be hard work because there's a lot more uncertainty associated with existing structures. And when you're designing a new build, but because the structural engineer plays such a key role in these projects that also really reward it to be involved with.

Audio - Gordon Harcourt

Collaboration in the design phase clearly crucial. How do we make sure it happens? What are the key lessons that you've learned?

Audio - Lisa Oliver

Yes. To really achieve a successful low-carbon building collaboration is vital and the earlier the better. So, I think good collaboration is about good communication and good relationships, and that's the design team. And of course, this isn't unique to sustainable design, but it's really important for a project that's got sustainable design objectives. So, these are really well communicated to the whole team and then everyone's working towards the same goals. And then the team needs to be able to communicate why they're making different decide decisions so that those decisions can be evaluated against the project goals to get the best outcomes, because there are always going to be compromises, but if we're working towards the same goal, then we can find a balance between efficiency and performance. And if you've got a design team that's really communicating well and has a great relationship, then those discussions just work so much better, and you end up with a much more successful project.

Audio - Gordon Harcourt

Kia ora Lisa, thank you. Great to hear from the engineers.

And this finally today, it's been quite a line-up. Finally, Scott Watson, he's the Business Development Director at Naylor Love. Kia ora, Scott.

Audio - Scott Watson

Thank you very much. And I really appreciate the opportunity the construction seat for Accord has given me to have a chat.

Audio - Gordon Harcourt

Scott, Naylor Love recently developed a carbon calculator, compares the emissions of different billing alternatives for a structure. What's the story? Why did you do that?

Audio - Scott Watson

Why was it developed? So, like a lot of companies, we decided to have a look at our own carbon footprint. So as a construction company, quite large, we looked at where the carbon was being used. And we quite quickly came to the conclusion that two or 300 diesel units and a whole lot of international flights, and a lot of bit pack consumption was where our sort of carbon was being utilised or used up.

So, we did the calculations then we set targets to reduce that. And then we sort of sat back and thought, is it the best bang for our buck? So, we commissioned some investigations and we started looking at different carbon materials and what you build your building out of, and what that effect would have. So, it became very apparent very quickly that while we were doing the right thing, in terms of our vehicles, reducing the number of diesels, introducing hybrids, we were putting solar parents, some of the sites and some of the pluses reducing area travel. We would get major payback by simply changing the selection of materials and some buildings. So really it was born out of trying to get best bang for our battle.

Audio - Gordon Harcourt

And has the calculator made a difference for you guys?

Audio - Scott Watson

What it did quite quickly was it allowed us to quickly advise clients of their options and the effects of the materials they selected. So, what our calculator does, it's quite simple, it's quite straightforward and it only measures upfront carbon. So, what it does is it compares the designs of buildings with different materials and measures the carbon content. So, we don't get into a whole lot of detail at this stage in terms of the operational component of the building or the end of life argument. The end-of-life argument of carbon is quite fraught in terms of what happens to the building 50 to 100 years.

So, we've been quite clear that what we're just is comparing two or three different design options, concrete steel, hybrid, timber, etcetera. And then we can show the client, what the difference in the CA two governments are and what the difference in costs are, so they can make an informed decision. So just gave us a whole lot of background information to be able to do that quite quickly.

Audio - Gordon Harcourt

You've since made the tool freely available for others to use, good on you. Why?

Audio - Scott Watson

Yeah. So, what was happening is every time we did a presentation, the first question we could ask afterwards is can we have your carbon calculator? And initially we said, no, you bring all your clients in Naylor Love, and we'll help you out, that quickly got to the point where the carbon calculator has been requested so much and it was in circulation anyway, I think these days when something gets available electronically, it circulates on its own Accord.

But so, what we did is we to control it a little bit, we actually put a slightly different version online and we put a set of guidelines and restrictions around the use of it. So, it was quite clear what you should be using it for. And we just thought it was easier to put it out there in the right format so that everyone can utilise the factors. There'll be other calculators that are on the market and there's other ones that you can utilise. So, we didn't think we were actually losing anything by just making it public.

Audio - Gordon Harcourt

Naylor Love, one of the biggest construction companies. What do you guys see as the key challenges in reducing carbon emissions in construction?

Audio - Scott Watson

So, there's a few things in terms of supply chain and design and standards. And at the moment, the New Zealand industry is used to designing quite rightly its own concrete and steel and the use of say engineered timber is relatively new. So the supply chain also has its issues in terms of there's only one or two manufacturers and certain parts of that engineered timber space. So we've got a ways to go and it doesn't all anti concrete and steel. I mean the concrete and steel industry during their best in terms of looking at recycling and looking at using low carbon concrete with fliers substitutes as well.

We're not saying it's the answer for everything, but the significant advantages news and timber where you can, and we just have to manage that process in terms of making sure that we can get the supply in a timely fashion. So, a bit more planning, a bit more detailing by consultants and design team to make sure the whole shop brewing process is sorted out as early as possible. And so definitely if you can get the procurement sorted at the front end, get the design process advanced a bit further than perhaps you normally would. It is a very quick, efficient, and low carbon way to build.

Audio - Gordon Harcourt

Kia ora, Scott, thank you. And thank you to all our speakers today. Thank you to you for watching the webinar. We really hope you picked up some practical tips, some real understanding of reducing carbon emissions in construction.

Now, if you have any questions, please do email the Construction Sector Accord, the website is on screen now, or visit a website for more information. We hope you'll join us for the next in a series of towards high performance webinars.