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Changing our calculations to put carbon reduction first

September 24, 2021

By Josh Grantham

Built environment consultants have a choice – to drive climate positive change, or to enable the status quo

Across development sites, contractors are appointed to carry out the carbon-intensive heavy lifting such as earthworks, roadworks, foundations, drainage, utilities and building construction. The carbon footprint that developers are considered responsible for, is lower in comparison. We already have standards in place such as PAS 2080 which allow us to measure the carbon intensity of each project, across materials, processes and associated CO2 emissions. In theory it’s an easy calculation and is being used across major infrastructure schemes, but are we doing enough, or using carbon calculations enough to change behaviours and build infrastructure fit for the future? Or.. are we just counting for counting’s sake?

It’s time the construction industry made a concerted effort to measure and manage carbon in infrastructure. This will not only inform our design decisions, material choices, construction methods and suppliers, but will lead us to unlocking cost and carbon savings which are, more often than not, being missed with current design practices. We can then embed these lessons into our ways of working via current and emerging technology and/or design software.

We need to include carbon calculation, and reduction as an intrinsic part of our work at all scales, from strategic highway schemes to local housing developments.

Can we think carbon first?

At the moment, we calculate the total carbon emissions and embodied carbon involved in major projects and identify potential reductions. But would looking at this from another perspective drive change—by setting policies at the start. Could we set a carbon quota that projects and developers need to meet, and drive a shift change in thinking ‘carbon first’? 

Another shift would be managing the remit of civil engineers and project management better and involving key stakeholders earlier. The biggest opportunities to reduce embodied carbon are at the start of a project, where the big strategic decisions are first made. Engineers need to be front and centre for early decision making, but as designers, we’re often not brought in till a later design stage. Consequently, we’re missing a huge opportunity to calculate further reductions and drive change.

Engineering change in the design process

To what extent do our civil engineering teams know how much embodied carbon can be reduced? We must train our engineers and give them the confidence to inform and challenge clients on how we can do things differently. There’s a trait that often occurs in engineering, where a problem is only considered to be solved by adding a solution. Rather than reconsidering the problem, this can build up, where the previous solution needs another solution—and we overburden the problem. We need to simplify and reduce the danger of over-specification so that all solutions serve a purpose. In many instances, we could apply a ‘do minimum and manage’ approach to design. 

Our current system doesn’t allow us to think of the bigger picture and we let our designers get caught up in the detail. For example, when we design roads, the focus is on durability, and not carbon reduction—we know the road will last. We play the game of adoption, and the job is complete when the Highway Authority approves the drawing pack. This means we often miss opportunities to create better design outcomes, only to the detriment of future communities.

Finding quick wins, then building on them

Across our infrastructure, there are a number of quick measures to reduce embodied carbon, some of which are already being rolled out.

On our roads for example, we can reduce carbon by up to 30% by lowering the temperature of surfacing. We can change our choice of materials—by recycling, using aggregate concrete, and ensuring we use a local supply of materials synonymous with the region where the project is being constructed.

On its own, the process of changing materials can have a high impact – or it can be more of an incremental change where the materials’ overall contribution to the project could be merely a small percentage. Either way, we need to continue rolling out all the measures at our disposal—everyone doing something to reduce carbon at all stages is far more effective than just one area of intervention. As designers, we should also consider operations maintenance and decommissioning—any carbon considerations should be covered in the whole life assessment.

Eyes on us as enablers

Our new infrastructure programmes should be carried out with a low carbon future in mind. While it’s important that we set our own sustainability and carbon neutrality targets, as individuals and an organisation, we need to remember we’re enablers of more embodied carbon through our designs as consultants to the construction industry. It’s our responsibility to keep carbon management and the forefront of our minds with an aim to keep carbon impact as low as possible and to realign the way we design and build our projects. With each project, are we considering if our actions will have to be inherited by someone else in the future? Are we giving future generations the greatest chance of tackling the big issues?

It’s our responsibility to keep carbon impact low and to realign the way we design and build our projects. Are we giving future generations the greatest chance of tackling the big issues?

Whether we’re working on a major infrastructure scheme, or supporting a small housing development, this future thinking shouldn’t be an oversight. As enablers of significant carbon emissions, we have a duty to change our behaviours, own up to the consequences of our work, and always seek lower carbon methods. Do we always need a new road? How can we help change social behaviours and shift the demand?

As enablers of significant carbon emissions, we have a duty to change our behaviours, own up to the consequences of our work, and always seek lower carbon methods.

Caught between a crisis and a hard place

The dilemma is carbon intensive growth versus climate emergency—we can’t build developments without carbon, even if they are net zero ready. The UK currently needs 300,000 new homes annually. We’re faced with the paradox of needing to deliver sustainable growth – how do we rapidly build, heat, and power the thousands of homes required to solve the housing crisis, while also meeting challenging net zero targets?

One of the many ways is to review the UK ownership model which makes us consumerists: marking personal success by owning a car, and a house. How we strive to own these after years of saving, without questioning our motivation: do you want to purchase a car or mobility, a building or a home? 

We’re faced with the paradox of needing to deliver sustainable growth – how do we rapidly build, heat, and power the thousands of homes required to solve the housing crisis, while also meeting challenging net zero targets?

We need to assess the quality and longevity of the houses we’re building in the first place. The property market may value a house at £400,000, but the value of the materials almost worthless—something that a single sale price cannot reflect. Can we revalue a house by assessing the land position, the material value, and its suitable for the future? If we don’t do this, we may over value a property, missing then the opportunity to redevelop sites that would enable us to meet the low carbon housing need.

The new Building Regulations part L set to be introduced later this year looks to ensure the UK builds zero carbon ready. But this is only in principle—these houses may still have gas boilers. They might also come with two or three car parking spaces required through policy; yet this doesn’t align with the transport agenda to encourage more public transport users, or the current trends of ownership (and financial barriers) in younger people. Such regulations might aim to be future ready, but with just 29 years until our net zero target, this really isn’t enough.

Publicly conscious, conscious public

A lot of carbon is really hard to spot, and some activities don’t feel or appear damaging or carbon intensive. Take for example, fumes being pumped out of a car – bad. Building a wall or pouring concrete? Bad…? In the world of embodied carbon, they’re the same. An Electric Vehicle might alleviate a driver’s environmental guilt, but its

manufacturing process is still hugely carbon intensive, and no EV is truly green if the electricity used to power it isn’t.

We’re seeing the most conscious developers now talking about lifestyle changes and how for the next generation, the principle of ownership is dead. Their future looks at communal buildings, cinemas, gyms, and shared green spaces. We need to change the fabric of our cities, which are stuck within a paradigm of ownership—of housing, cars, gardens etc. The issue of sustainability and active travel is certainly not fixed by just adding a cycle lane adjacent to a highway. We need more all-encompassing thinking and perhaps a paradigm shift.

Celebrating change

Currently there’s the narrative that to do something for the environment, you lose out personally—that my life will change drastically (and negatively) for the good of the planet. As enablers of future developments, it’s our responsibility to demonstrate how a low carbon future can be socially beneficial. We should celebrate when the infrastructure we build is better for both humans and the environment. At the moment, being on budget or schedule is the main cause for celebration.

The way we have lived, worked, and moved has shifted substantially over decades, with transport revolutions, trends and demands. Even before the pandemic, the younger generation were exhibiting significantly different travel behaviours than the older generation – with young men travelling almost 50% less by car than their counterparts 20 years ago. We can, and must, have the discussion, assess new demands of humans and the planet, and make sure our new infrastructure meets them. Change is possible, and essential. 

About the Author
Josh is senior sustainability urban consultant and works with infrastructure development clients to assess and reduce carbon across a project life cycle. 

  • Josh Grantham

    As a senior urban infrastructure engineer, Josh has a skillset that blends engineering, urban design, transport planning, sustainable development, and active travel design.

    Contact Josh
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