Sam Patterson, embodied carbon assessor, Atelier Ten, on retrofit, realism & supporting material innovators in crossing ‘Death Valley’.

As our focus on the race to reduce carbon in the built environment continues, we pick the brains of Sam Patterson, embodied carbon assessor at engineering consultancy, Atelier Ten.

The theme for this interview was initially sparked during a chat we had with Sam, in which we discussed low-carbon materials. He referred to the challenge for material innovators in getting their products to market as being like “crossing Death Valley”. A sentiment which resonated with us, having heard of the many hurdles faced by biomaterial designers, for example, the likes of the exhibitors in our own exhibitions, over the last 5-years.

To achieve the net zero targets, supported by the new UK Net Zero Carbon Buildings Standard though, materiality plays a crucial role. “Tinkering with business-as-usual materials”, Sam says, just isn’t going to cut it.

In this week’s interview, we consider the low carbon innovations that should be brought to the fore – and how that might happen, the positive force that is NZCBS, and the ESG domino effect catalysed by funders.

Firstly Sam, please can you tell us about your role at Atelier Ten?

“Within the Environmental Team of Atelier Ten I undertake Carbon Assessments from small optioneering tasks to full Whole Life Carbon assessments, and work with clients and design teams to identify viable carbon reductions.

“I am most passionate about how we adapt the business case for the circular economy and regenerative building materials to ready ourselves for a decade of declining carbon limits.”

What does embodied carbon assessment involve day-to-day?

“Embodied Carbon Assessments can vary in scope. A Whole Life Carbon Assessment requires you to investigate all aspects of a building, looking at environmental impacts at the product stage, construction stage, whilst in use, end of life scenarios and the circularity of the materials.

“In practice, this can be a lot of time in Excel quantifying a design using cost plans, design access statements, drawing packs and gathering data from the design team on energy demand and water consumption.

“A Whole Life Carbon Assessment is time intensive - the more time you put in, the more accurate the result will be. But indicative outcomes can be made from high level calculations. The process is meant to inform better decision making but currently more time gets spent on completing an assessment for compliance than working collaboratively on how to achieve significant reductions.”

What's your initial reaction to the new UK Net Zero Carbon Buildings Standard?

“The NZCBS will have a positive impact primarily for two reasons. The first is the reach of the standard, its has not been developed in isolation, with a high level of stake holder engagement and there are several professional bodies poised to adopt it. This creates a shared ownership that builds resilience.

“The second reason for its success is that it brings clarity on Net Zero alignment to national targets while considering a wider number of building types. Each building typology has its own annual limits with a pass/fail mechanism that I believe leaves less room for greenwashing. Is there room for improvement? Always. And this is built into the pilot process.”

How is the NZCBS affecting your project work?

“Projects that are already mid process are working to existing frameworks and targets, so our duty is to highlight the pilot version of the NZCBS to clients and understand how existing designs fair, and whether future proofing is required for when the standard is officially published and adopted as a non-voluntary requirement.”

Is carbon a consideration on every project?

“It depends… Carbon is now established in the consciousness of clients and design teams but there is a spectrum of responses. ‘It’s not important to this project’. ‘It’s not a requirement’. ‘My fees don’t cover it’. ‘We now need a whole life carbon result for a funder’. ‘We will tick the boxes’. ‘We can use the assessment to improve the design’. ‘We are considering carbon impacts during concept optioneering’. ‘We want to be an exemplar of Net Zero construction, what innovation can we adopt?’ Fortunately, we tend to work with more enlightened clients who want to understand and manage their impacts.

“Funding requirements will drive the early adopters in the public sector or with investor requirements. Planning requirements will drive the early and late majority in the belle curve diagram. But some projects may just be too small to undertake a Whole Life Carbon Assessment, in which case we should rely upon best practices guides, for say domestic retrofit, and apply principles of low carbon design.”

And how does this compare over time?

“Every Kg of CO2e that can be avoided today is one less to be removed tomorrow. As such, the harshest carbon reductions are over the next ten years and this is the time it takes to plan, develop and construct significant projects.

”The time is now. If you must build, build well. It is a carbon investment in the future.”

“However, we can’t be idealistic about only accepting say mass timber buildings or thinking that everybody wants a straw bale house. Materials need to be economical, available in volume, and considered safe for their purpose or building type.

“The speed at which new construction products become available on the market can be painfully slow, requiring large supply chains to be improved or constructed before you get to marketing a product with the necessary testing and environmental data.”

How is it being tackled?

“Operational Energy has been the priority in recent years. It was more readily quantifiable and affected running costs, but low energy bills doesn’t always mean low carbon emissions, as metals, critical minerals, refrigerants and replacement cycles of new technologies require highly refined materials and typically energy intensive processes. A balance is required, and you need to have the data to come to the lowest carbon option, this is why I prefer early stage optioneering.

“Embodied carbon emissions are harder to address, in my opinion. To expand on a previous point, the time it takes for the construction industry to conceive, test, accredit, adopt and mainstream a new material, especially one that is a departure from the existing tried and tested practices, can take over a decade to bring to market and that is before you get to a market share that starts displacing the need for high carbon materials.

“The circular economy can have a significant impact by ensuring that we Reduce, Reuse, Recycle and Recover existing materials, decreasing our reliance on virgin resources, and products with Cradle-to-Cradle credentials can maximise reuse by closing the loop, or Cradle to Grave products and be cascaded in multiple downcycled products.

“The goal, keep it in the loop as long as possible.”

“The UK is reliant on a European supply chain for a lot of our construction materials. Currently 60% of the steel in the UK is imported. In 2023, the UK produced 5.9m cubic metres of sawn timber and timber panels but consumed 14.1m cubic metres of sawn timber and timber panels, importing the 58% short fall. The UK produced 8,393 mega tonnes of cement in 2023, and consumed 12,010 mega tonnes, relying on 30% imports. So, we are most self-sufficient on concrete as a primary building material.

“I would like to see the UK become a remanufacturing economy, an island nation with a high level of self-reliance because we use our fair share of resources that we are able to create, it’s good for the economy and it’s good for carbon.”

When we last spoke, you referred to innovators getting to market as being like 'Crossing Death Valley' - can you elaborate on that for our readers?

“Tinkering with business-as-usual materials is not enough. Focus is shifting to how material choices can be restorative and regenerative with a positive impact on all of the planetary boundaries.

“UK nurtured innovators, with disruptive product innovations, who are successful in receiving academic support, public grant funding still must cross the valley of death and attract enough private investment to establishing manufacturing and bringing a product to market.

"The best way for the industry to overcome the valley of death is to evidence a commercial pipeline for investors by exploring new suppliers, discussing risk, and specifying appropriate low carbon materials.

“Can your project adopt and champion a material or product that has non-traditional project benefits, where you give the design team the time to fully explore the risks and opportunities? It’s difficult to break the Time/Cost/Quality trifactor. Quite often though, you will find added value from.”

There are challenges with using what could be perceived as 'risky' materials - what's your experience of that?

“Asbestos and Reinforced Autoclaved Aerated Concrete are maybe the two high profile materials where opinion and performance has changed over time. If you look at the early marketing materials for asbestos there are some great claims, but they missed the long-term health impacts which took time to manifest.

“If you are looking at a novel building material, there is always a risk of unintended consequences as current testing requirements can only provide results against existing standards - and new standards may be needed. These take time and cost money, which is why the burden falls to the manufacturer to prove themselves, but they need the opportunity to prove themselves with suitable demonstrator projects backed with academic and regulator support.

“If you consider the circular economy, the use of pre-consumer and post-consumer waste to increase the recycled content of a new product requires the manufacturer to be confident that their supply of recycled material is not contaminated and is available in sufficient volume. Accepting recycled materials from a variety of sources introduces more variables when compared to petrochemical derived products that have relied on a high volume of highly refined substances.”

Timber you highlighted as the 'litmus test' for combustible materials…

“Timber has a low ignition temperature when compared to steel, concrete, or glass, making it a combustible product, and the UK is exceptionally sensitive to fire risk following the fire at Grenfell that led to significant loss of life. Timber products have a significant presence in the current UK construction industry and the media tend to use timber as a worst-case scenario using imagery of domestic house fires. In European markets, we tend to see more ambitious use of biobased materials to meet carbon emission reductions with new companies receiving public support to bring regenerative materials to market.

“I refer to timber as a litmus test for bio based materials because there is an understandable aversion to specifying combustible products without looking at the associated risks. Of all the biobased materials, timber must have the most amount of research as the small details matter, how do different species of timber perform, how do different species from different countries perform, what impact does the coatings of adhesives have and the depth of knowledge is increasing, helping design teams develop better building systems?

“Sitting in the shadow of timber is hemp, straw, miscanthus, flax, cork, seaweed and other harvestable crops that are typically made of cellulose, like trees but can sequester carbon on an annual cycle without the land use implications of timber plantations. It would be great to value our farming heritage and support rural communities to create food and raw materials.”

As architects, designers, and property professionals, what can be done to support innovators?

“Use carbon targets and our planetary boundaries to advocate for change in the way we shape our buildings.

“Work with the supply chain to understand the Environmental Product Declarations and the social and environmental value of materials.

“Find the opportunities for demonstrator projects and learning opportunities in projects that can seed change.

“Be patient, it’s not all going to happen at once, and nor should it. Overnight change does not create a fair and just transition to a low carbon economy - time, research, skills training, and collaboration are needed.”

Can you tell us about some of the innovators you're keen to support?

“This is going to be extremely unfair, and many of them already feature in your This Is No Longer Speculative exhibition, so I’m just going to say, find the materials with a social value story and those that have considered their own impacts across the supply chain.

“The materials of the future will leave a positive impact.”

What do you think are the next steps in bridging the gap between innovators and industry?

“More collaborative projects using a mix of public funding and private funding to scale up the current UK support network.”

Are you hopeful for the future of the built environment?

“I am hopeful, as I see that change is possible - and I’m more afraid of the consequences of inaction.”