Shikha Bhardwaj from Hawkins/Brown says understanding whole life carbon is no longer a choice; it’s essential knowledge for architects on every project. She explains the standards which are emerging to embed carbon measurement into the industry
We are all familiar with counting the calories of what we consume in order to live a healthy life. In a similar way, to improve our planet’s health we need to be mindful about the number of resources we consume, the quantity of emissions we generate, and the other impacts. This is key if we are serious about tackling the climate emergency through urgent action before 2030.
Why is understanding whole life carbon essential?
Hopefully, it is common knowledge by now that the built environment is contributing to 39% of the global emissions that are warming our planet, out of which 11% is from materials (based on UN data). To minimise those emissions, we need to understand the contribution of each life cycle stage, including end of life, and particularly of upfront embodied carbon (which is divided into modules A0-A5).
A well-structured whole life carbon analysis process, integrated into the design process, would help designers to understand the embodied and operational carbon emissions they are creating, and to work to minimise them from the early design stages.
Current industry information about whole life carbon
There is a plethora of information available, which at times can be overwhelming! The key is to break it down and understand what is mandatory and regulatory and what is for guidance. Firstly, there are International ISO and PAS standards governing how to measure and manage carbon emissions. Then there is BS 15978 that details the life cycle stages used to do a whole life cycle assessment (WLCA), and BS BS15804 that governs how Environmental Product Declarations (EPDs) are produced consistently. The RICS Whole Life Carbon Assessment for the Built Environment Standard 2023 translates this into the pragmatics of how to produce the calculation and report it consistently for buildings and infrastructure projects.
Alongside this, there is a lot of industry guidance including the LETI Embodied Carbon Primer, IStructE, RIBA, CWCT, CIBSE TM65 and, soon to be released from the UKGBC, the UK Net Zero Building Standard. It is important to realise this guidance does not replace the RICS standard, it all amplifies the information in that document for a specific audience. There can be mandatory project requirements from certifications such as BREEAM, but it is important to note these calculations do not currently follow the full RICS standard scope. Increasingly, WLCA is mandated by planning regulation. The GLA has required the submission of these calculations for major or referable projects since 2020. They indicate benchmarks but no limits. Other local authorities are following suit, but in different ways, depending on location.
To summarise, it’s fair to say we have all the guidance we need; what’s required is the legal act of making it mandatory and measuring consistently across the UK and upskilling teams to do that. Part Z can help make a start.
What is Part Z & why do we need it now?
While it is well established that measuring and reporting whole life carbon is essential for emission reductions, it is still not a mandatory requirement within the UK Building Regulations. It is clear there is an emerging variance in how it is treated within planning authorities – and hence within design practices. As a result, in 2021, a group of five experts – multidisciplinary sustainability professionals – developed Part Z. This was a proposal for amendments to the Building Regulations to mandate the reporting of WLC and eventually, the limiting of carbon emissions.
The document is available online, and its clear intentions can provide a needed direction to the industry. Part Z1 plans to help normalise the use of WLC assessments within the building design process, to identify easy wins and key contributors early on, and then ways to reduce the WLC impact. Part Z2 is intended to “discourage excessive and unnecessary use of resources within the built environment, by setting a reasonable standard of efficiency for the upfront embodied carbon intensity of the building.” Part Z1 is envisioned to gather quality assessment data as a first step, and use it to determine realistic national targets for upfront embodied carbon for Part Z2.
How could Part Z drive a sustainable built environment?
Key to carbon reduction is consistent measuring with defined scopes, but also using the outcomes to influence design. Part Z would bring a steady approach to measure both operational and embodied carbon, so it becomes part of the design thinking. For better built environments, analysing operational emissions early on would help ensure that buildings are designed using passive principles, with efficient systems, low carbon technologies to minimise energy demand, and hence emissions.
For embodied carbon, iterative analysis could help focus on minimising up-front carbon by using low carbon materials suitable for the building use and requirements, while not ignoring the durability and replacement cycles (Modules B-C and D). Early measurements would help draw attention towards reducing the upfront embodied carbon, which is key in the current climate. It is the largest proportion of embodied emissions in the WLC and will be released in the immediate future for buildings being designed now. However, for a well-informed decision it is essential to take a long-term view – to understand what operation, maintenance and replacement cycles mean through WLC results. Part Z could be used to find that balance, between upfront and WLC and then between embodied and operational.
Furthermore, the improvements and reductions could be fairly compared between different projects regardless of where and who is doing the analysis within the UK; this helps to scale-up. Regulating WLC would further drive the retrofitting of the existing building stock instead of building a new, supporting circular economy.
How is it going to bring challenges and opportunities for key players?
We need to recognise that WLC is a skilled task, therefore one of the key challenges is upskilling. This applies to clients, regulatory bodies, designers, contractors, and manufacturers. For clients it is key to understand what they are committing to, for regulatory bodies to comprehend data and review the proposals presented during planning; for contractors and manufacturers it means upskilling the teams with WLC methodology to allow regular monitoring required on site so set limits can be achieved.
The other challenge is the associated cost, as clients will have to pay for specialist services, and depending on the pace of up-skilling, others might have to rely on limited third party verifiers, hence additional cost.
But the investment brings necessary, long-term benefits. Following this approach will add to certainty in the process and outcomes once the initial phase of introduction is over, and will bring opportunities to incentivise a low carbon material supply chain. When regulation is introduced, it will allow long-term investment to be made. This will directly benefit the innovative products that currently struggle to get traction and certification, due to the large costs involved. This will also mean that existing buildings can be looked at as ‘material banks,’ and the first instinct will be to reuse and not build new.
Part Z’s wider impact
This one act can bring a huge shift in how we design and assemble almost anything. Currently, there is a huge gap as only a small group are following the approach, but with amendments to regulations this will change drastically. This will mean that everyone follows consistent methodologies and there is transparency, and will build up the quality database that the industry urgently needs. But the key transition it will bring is our outlook on the environments we have built already, including use of circular economy principles, using our cities as material banks, and urban mining to reduce the emission figures.
The power of Part Z will be escalating the demand to invest and research into innovative low carbon materials and new techniques of construction (using existing materials) and how we record and use material information. We have seen a huge uplift in discussions and explorations around structural efficiencies, retrofit and low carbon materials such as timber as an outcome of WLC conversations. This needs to be carried forward for our design thinking to expand, and for the phasing out of outdated carbon-intensive construction approaches that are clearly not good for the health of our planet.
To conclude, Part Z can bring a step change, and this regulation of WLC has been supported by more than 100 firms of developers and architects, including ours.
Shikha Bhardwaj is lead sustainability designer at Hawkins/Brown