RICS whole life carbon assessment standard – how does it support the industry?

At over 200 pages, the RICS Professional Standard Whole Life Carbon Assessment for the Built Environment builds extensively on the 2017 original. But what does it clarify and how will it support the industry in completing Whole Life Carbon Assessments (WLCAs) properly?

As the 2^nd edition of the standard has come into effect (from 1st July 2024)  RICS members are expected to follow all requirements specified for the relevant project phase and type.

Carbon consultant Simon Sturgis RIBA, and lead author of the updated 2023 standard, discusses the opportunity it presents and how he hopes it will steer the UK closer to its net zero objectives.

Why does the industry need a new standard?

Back in 2017, the RICS standard was a first for the industry.  It provided the industry with a tangible method for estimating the amount of carbon emitted throughout the life cycle of a constructed asset, over the various stages of a project – from the upfront carbon, released as a result of the sourcing of materials, transport and construction, through the ‘in use’ phase, to the deconstruction and demolition involved in the end-of-life phase.

The need to put more focus on embodied carbon had already been highlighted by several leading figures in the industry. But it tended to be an overlooked part of the process. Since then, the context has changed dramatically.

As Sturgis says: ‘From the introduction of UK government net zero legislation in 2019 to the Glasgow Climate Agreement at COP26, we had a clearer set of objectives for what the built environment needed to achieve. We needed a new version of the 2017 standard to reflect that.’

There was also a growing body of evidence regarding the contribution that embodied carbon (also known as Scope 3 emissions) makes to total greenhouse gas emissions. In 2021, UKGBC reported that annual embodied carbon emissions in the UK originating from the construction, maintenance and demolition of buildings amounted to 40-50 million tonnes of CO2 – more than the combined emissions from aviation and shipping. A more recent report in 2023 by Akerlof, Carbon Blond Spots, estimated that Scope 3 emissions account for 94-98% of Tier 1 contractors’ emissions.

And while the High Court recently overturned Michael Gove’s controversial decision to block the demolition of Marks & Spencer’s flagship Oxford Street store, Westminster Council is the latest to ask for WLCAs for all major redevelopment schemes.  The latter confirms the industry needs to get better at assessing, evaluating and comparing the carbon impact of both retrofit and new builds.

What differentiates the new standard?

One of the great challenges in the industry for reporting carbon emissions was finding a way to consistently measure and report them – in fact, the original idea for the update was called the Consistency Project.

Over the past seven years, the industry has made substantial progress in overcoming many of the challenges involved in measuring, reporting and benchmarking carbon, which thwarted earlier attempts to tackle the issue of embodied carbon.

Over that time, several professional institutions, including IStructE, RIBA and CIBSE have produced guidance in their specific areas. For example, CIBSE’s ‘TM65 Embodied carbon in building services’ presents a calculation methodology for calculating embodied carbon in building services engineering. Typically, energy is assessed in kilowatt hours. The new RICS standard, however, includes a methodology for translating energy into carbon, which means every asset can now be assessed in terms of carbon emissions both operational and embodied, for the first time.

Sturgis says: ‘This is particularly important as it enables carbon cost/benefit analyses. It means it’s easier to answer questions, such as – ‘what is the embodied carbon cost of installing more insulation compared to the corresponding carbon benefit in reduced energy use?’ He adds: ‘These types of calculations can help to ensure the design stage becomes more efficient and streamlined, saving time and money in the long term.’

The scope of the updated standard is far broader than the 2017 edition. Where the original version focused mainly on offices, the second 2023 version covers all building types and includes retrofit, refurbishment and fit-out. It also covers a comprehensive list of infrastructure asset types – both local; roads, drainage and national; railways, dams, reservoirs, and airports. This means calculations for all are using the same methodology. And just as traditional cost plans have a contingency figure, the standard introduces a contingency based on project stage, reliability of carbon data and reliability of quantities data.

The guidance recommends that all WLCAs follow a modular structure for carbon reporting, which breaks down the built asset’s life cycle into stages and modules (see figure below). This has been adapted from the European Standard EN 15978 that assesses the sustainability of construction works.  With the built environment responsible for around 40% of global carbon emissions, it’s crucial for all countries to have a globally consistent method for whole life carbon reporting, as well as a methodology for all building and infrastructure construction projects. Therefore, the standard is also aligned with The International Cost Management Standard 3 (ICMS3).

Do WLCAs help or hinder communication throughout a project?

If completed properly, a WLCA could help to identify any potential problem areas and gather vital information, with greater accuracy and speed, that could benefit all parties.

Sturgis highlights any challenges that could arise from initial assumptions. ‘If they’re calculated incorrectly, the distorted figures can place unnecessary pressure on other materials and resources – in terms of reducing their cost or carbon values.’

Sturgis cites the example of a new build office project where they discovered a disproportionate amount of ‘carbon’ below ground level after undertaking a whole life carbon assessment.  This was due to the foundation cost assumptions that were based on the longest, fattest pile multiplied across the site, which distorted the overall figures and meant there was undue pressure on the cladding and in other areas. This had occurred to give the quantity surveyor an undeclared additional contingency. The carbon assessment therefore helped provide greater precision, both in terms of carbon values and financial accuracy.

Sturgis says: ‘We’re still in ‘new terrain’ and assessors will require ongoing training to get to grips with the four modules in the standard – product and construction, in use, end-of-life, and reuse and recycling.’

He offers a word of caution: ‘It may be more difficult for a less experienced assessor to make accurate assessments of life cycle replacements, which will of course vary from project to project.’ He adds: ‘But with time and experience, it should be possible to develop reasonable scenarios for the maintenance, repair, replacement, refurbishment and operation of the built asset – as long as it’s based on project-specific information and is in consultation with the project team.’

He acknowledges that although it may be tempting to ‘improve the figures,’ assessors need to be realistic and transparent about their assessments for all major components, including life cycle costs. This is especially important to ensure their clients are future-proofed against stranded assets or the possibility of failing environmental standards or green audits. However, ‘the onus is also on industry bodies to provide adequate training for assessors.’

Is the tide turning for embodied carbon?

Sturgis emphasises the standard isn’t a strongarming device to force anyone into lowering carbon emissions, rather it’s ‘guidance’ for professionals who want to arm themselves with the necessary tools. However, he feels the tide is turning in the industry, as more developers are now concerned about embodied carbon alongside operational carbon. We’ve seen this recently as many more are considering retrofit over demolish and rebuild, even if their development plans have been accepted.  And, as a recent survey by the construction consultancy firm RLB found, 33% of contractors are being asked by clients to provide whole life carbon assessments on schemes, a substantial increase from last year’s 14%.

Will retrofit-first policies become more commonplace?

As councils across the country strive to reach their net zero targets, it’s likely that ‘retro first’ policies will continue to gain traction as a low carbon strategy.  However, Sturgis maintains there are cases where demolition and rebuild will remain the best option, especially where assets are beyond economically and environmentally viable reuse.

At a RICS debate in March this year, the panel discussed whether the UK should be regulated on the principle of ‘retrofit first.’ Simon Rawlinson, head of strategic research and insight at Arcadis, urged the audience to consider what innovation could have been lost in the decade of recent architectural history had this been policy at the time and what society could stand to lose in the future if it were adopted nationwide.  Henrietta Billings, director of Save Britain’s Heritage stressed the importance of finding a consensus and called for a system that favours mandatory whole-life carbon assessments. If, or indeed when, that happens, the industry now has more tools at its disposal that can provide the data that these decisions require.

Will the standard move us closer to designing and constructing low-carbon buildings?

Yes, because if you can measure you can then reduce. The RICS Standard is encouraging both developers and the supply chain to evolve to achieve lower whole life carbon outcomes.

For example, several architects have constructed buildings using timber, which have, quite rightly, been praised for their low-carbon credentials. However, the carbon values of the material need to be assessed over its entire lifecycle. For example, if the use of timber increases from around 4-5% of construction materials to 25%, this could have a major impact on forestry across Europe and the world. In short, there is no single solution when choosing materials, as each situation must be judged on its own merits.

However, there are general principles for constructing low-carbon buildings that need to be considered when choosing materials – they need to be robust and durable, yet also lightweight, flexible, and adaptable. This is no easy task for today’s designers and engineers as, typically, these specifications conflict and need to be reconciled.  But these are the contradictions Sturgis hopes today’s designers and engineers will be able to resolve with imagination and creativity.

He says: ‘There are no easy answers to our current challenges, but I think they’re a catalyst for innovation in the industry. We must find a way to build 300 000 new homes a year, and this won’t happen through retrofit, alone. Therefore, we must design better, long-lasting buildings for our society that, ideally, won’t contain materials or components that need regular maintenance or replacing. He adds: ‘I hope that the reuse and recycling of parts and components of buildings will become a bigger part of the equation.’

What will the standard achieve?

Sturgis says: ‘I think that the more accurately you can calculate, the more accurately you can reduce carbon emissions. This is crucial if the built environment is to support the UK’s journey to net zero.’ He adds: ‘I hope the standard will ensure that WLCAs become a regular and expected part of every project, which will contribute to the design of buildings that are more cost-effective, more durable and more sustainable.’