In this article, whole life carbon assessment expert Daniel Doran takes us through what whole life carbon assessment is, why and how is it done, and explores how it relates to fit-out and interiors.

Whole life carbon
Buildings cause carbon emissions over their whole life from initial construction, through operation and at the end-of-life. The term ‘whole life carbon’ (often abbreviated to WLC) refers to the total emissions due to the building over its life. WLC covers both embodied carbon (due to construction products) and operational carbon (due to energy and water used by the building).

WLC assessment is the principal way to work out and reduce WLC emissions. Assessment at the design stage are useful for evaluating alternative designs options to reduce carbon, and for an early indication of performance against targets or benchmarks. Assessment after construction demonstrate as-built and operational performance, and can indicate the amount of carbon to offset to claim net zero carbon.

WLC assessment is based on building life cycle assessment (LCA), which has been around for longer. Whereas building LCA can give results for a whole range of environmental issues, WLC focuses on, you’ve guessed it, carbon. It would of course be much better to consider other environmental issues too but, with the climate crisis unfolding before our eyes and awareness and uptake of building LCA still low, concentrating on carbon seems reasonable. It means a single metric to focus on, rather than the confusion of keeping track of, and trying to improve, tens of metrics with difficult to understand units (eutrophication anyone?). Plus, the industry has data for carbon, from essential carbon data for products to benchmarks for different building types, along with reasonably well-developed measurement standards and guidance for designing out carbon. In addition, concentrating on carbon may increase the chances of new regulation in this area.

Whole life carbon assessment process
In a nutshell, WLC assessment involves entering most of the construction products and quantities in a building design into a building LCA tool, along with other factors like predicted annual energy use (usually from the energy modelling results). This process is governed by LCA and WLC standards, particularly the RICS Professional Standard ‘Whole life carbon assessment for the built environment’[1] (RICS PS) arguably the de facto standard for WLC in the UK. The RICS PS has recently undergone a major overhaul, including specific requirements for fit-outs (more on this later).

Sounds relatively simple, but the standards are detailed with aspects that building LCA tools cannot automate. For example, many products still have no environmental product declaration (EPD), so reasonable generic or proxy data needs to be identified and sometimes adapted (building services is a particular headache). There are often issues getting sufficient data from the design team or contractor – with the level of detail increasing at each project stage. Reasonable assumptions may need developing per product for things like wastage rates and replacement, along with potential routes for reuse, recycling or disposal at the end-of-life. Once an assessment is done, the results are not always easy to understand and how to reduce carbon is not immediately obvious, so careful analysis and interpretation by an experienced WLC assessor is essential.

Despite these challenges, many now see the importance of WLC assessment to understand and reduce carbon. So, forward thinking organisations are routinely working with external WLC assessors or developing in-house capability.

Currently, building regulations on whole life carbon (particularly its key component embodied carbon) are lacking. Apart from a seeming reluctance to regulate, there may be a lack of understanding that WLC is now relatively well developed in terms of standards and data, not to mention an apparent willingness from the sector to do it. Happily, some recent parliamentary activity[2] means there is a glimmer of hope that WLC regulation is at least being considered.

Meanwhile, local authorities have been taking matters into their own hands. Arguably the leader here is the Greater London Authority (GLA). The GLA began their journey into ‘regulating’ whole life carbon when developing the current London Plan. It is now a planning requirement that some larger projects do WLC assessment according to GLA’s detailed requirements as part of a planning application, and again after completion of the project. While there are no hard targets to meet, GLA do require reporting against a benchmark and evidence that attempts have been made to reduce carbon emissions.

Other local authorities have taken a lead in this area too. Some London boroughs, such as Camden[3], require WLC assessment to show that, where an existing building is present, a proposed demolition and new build scheme is lower carbon than refurbishment. These ideas are spreading further, with places like Bath consulting on it[4].

Happily, good quality guidance and tools for WLC have built up over the last ten years or so. Some of the organisations behind this are now creating the standards and tools that future regulation could be based on. A good example of this is the UK Net Zero Carbon Building Standard[5], due to be launched this year, supported by many influential organisations from the construction and property sector. If all goes to plan, it will be hard to talk credibly about a building being net zero carbon (or any similar description) if not backed-up by an assessment conforming to this standard. WLC assessment is centre stage in this.

Interiors and fit-out
Interior elements are a significant source of carbon emissions. The RICS PS and GLA’s WLC guidance both require that almost all construction products installed are included in the scope of assessments, including in the following interior elements (taken from the GLA guidance):-

  • Stairs and ramps
  • Internal walls and partitions
  • Internal doors
  • Wall finishes
  • Floor finishes
  • Ceiling finishes
  • Fittings, furnishings and equipment (FFE)
  • Building services/MEP

If you are involved in bigger projects as a client, construction product manufacturer/supplier, contractor or designer, particularly in the London area, you are likely to be involved to some extent in WLC assessment in the near future, if not already.

However, it is probably fair to say that WLC is still often overlooked on standalone fit-out projects, or where there are no planning requirement. Example elephants in the room are office, retail and hospitality fit-outs – major culprits for installing and stripping-out at an alarming rate. Most are probably aware that this is a very significant source of largely unchecked carbon emissions, but can’t see how this rapid, minimum time to think, way doing things is going to change. Nonetheless, forward thinking clients, spurred on by corporate sustainability drivers and increasing demands from switched-on tenants, are starting to require WLC assessment on their fit-outs. Some, like GPE[6], have their own targets. Plus, campaigners and the media are on the case, as the reaction to the recent Oxford Street M&S proposals demonstrated[7].

The updated RICS WLC standard – fit-out
While including interior elements has been required for a while, the latest version of the RICS PS has moved things on by including information on how standalone fit-outs should be handled in terms of elements to include (based around category A and B scopes) and the number of years assumed for a life of a fit-out, known as the ‘study period’.

The study period makes a big difference to the results. For example, a floor finish with a service life of 10 years assessed with a study period of 60 years will likely show 3 times more impact compared with a study period of 20 years (i.e. 6 installations and waste vs 2). To promote fair comparisons, the RICS PS generally requires the standard 60-year study period that the industry settled upon for buildings some time ago.

Unfortunately, while 60 years may be reasonable for much of the superstructure, it is often a problem for interiors because of the like-for-like assumption of replacement of space planning, products and finishes etc. over the 60 years. This is often detached from reality, where interiors change substantially as occupants needs and fashions change. There is a risk that a 60-year study period could influence the specification of interior products with unnecessarily long service lives – longer than the likely life of the fit-out itself. Where these longer service life products are also higher in carbon, higher overall carbon emissions could be an unintended consequence.

The recent update of the RICS PS, while still generally requiring 60 years (including for fit-out when installed as part of the same project as the rest of the building), comes some way to acknowledging that a shorter period may be more appropriate. The assessments of standalone fit-outs are required to include two sets of results – over 20 and 60 years. Although, this does beg the question: Which set of results takes precedence?

Making it count
Where teams have new requirements imposed on them without being given the required extra resources, time or training, a box-ticking mentality can be the result. Even with the best drafted regulations and standards, overlooking the purpose and finding the path of least resistance isn’t unusual. For WLC assessment this often means it becomes a siloed one-off exercise rather than being integrated into the design process – a missed opportunity for significant carbon reduction.

Successful whole life carbon reduction means having the will – at all levels – to do it well. With the right leadership, resourcing, training and access to expertise, project teams should respond very positively to WLC assessment. Delivering genuinely net zero carbon projects should be the norm not the exception.

Daniel Doran is a building LCA and whole life carbon expert who worked at BRE for many years, is a BSI and CEN committee member developing construction sustainability standards and is the founder