Can we have too much of a good thing when it comes to sustainability standards?

Chocolate, wine, cheese – we all know too much of a good thing can cause problems, but does this translate to how we look at sustainability performance?

In the UK, we have legally binding targets to achieve net zero by 2050 and reduce carbon emissions by 78% by 2035, compared to 1990 levels.

With 25% of UK emissions directly attributable to the built environment, hitting these targets will take a major step-change in how we approach building projects and manage existing stock.

The construction industry is rising to this challenge. Consultants, contractors and materials specialists are all investing time and resources into developing products, services and solutions aligned to the UK’s climate commitments.

At the same time investors, developers and industry bodies are setting their own net zero objectives and developing standards to achieve these.

One consequence of this very welcome activity is that there are now many ways of assessing and grading the sustainability performance of construction and the built environment.

NABERS lets us measure operational energy performance. EPC assessments give us asset ratings. BREEAM assessments use bespoke algorithms.

Meanwhile different industry bodies propose varying performance benchmarks and pathways. This means that understanding and interpreting project performance is now a specialist job.

The complexity is compounded by periodic changes in how we make these assessments, which can dramatically change the results.

For example, the EPC rating of a typical naturally ventilated office building will be very different depending on whether the assessment was carried out before or after June 2022.

In some cases, buildings with an EPC rating of B before the change in methodology will see this rating downgraded to D on reassessment, while other buildings will see their rating upgraded on recertification.

Even where methodologies are unchanged, seemingly innocuous variations in assumptions can result in big changes in results, particularly when looking at the rapidly developing area of embodied carbon assessment.

The sheer number of standards, metrics and methods is creating a challenge for the industry. At times, standards can be contradictory or overlap, leading to confusion, snowballing administration, and inefficiency.

The variety of different definitions also makes it difficult to compare performance between projects confusing the messages to key audiences such as investors and occupiers.

This variation can also impact supply chains and reduce contractors’ ability to scale solutions. This is because a solution, for example heat recovery ventilation, is needed in one situation, but may not be necessary in another.

A common framework of net zero standards would benefit the industry enormously, and it’s encouraging to see that work is already underway in this area.

In June, a collective of leading industry organisations, including LETI, the Carbon Trust, RICS and UKGBC launched a consultation on developing the UK’s first net zero carbon building standard.

Once established, likely in spring 2024, the standard will set out metrics for evaluating net zero carbon building standard performance, as well as performance targets, or limits, that need to be met.

These performance targets will align with science-based trajectories needed to achieve net zero by 2050 and a 78% reduction in carbon emissions by 2035 in the UK.

The UK net zero carbon building standard will bring much needed clarity to the construction industry. However, the industry must also lay the foundations for its success by becoming far more data minded.

Organisations will only be able to comply with the standard if they have an adequate understanding of the operational and embodied carbon emissions of their projects. Yet less that 1% of all new buildings measure whole life carbon impact.

At Currie & Brown, we’re on a mission to change this by championing a whole life cycle approach to decarbonising our built environment. We use a whole life carbon management tool and data and insights on carbon emissions acquired across the full life cycle of various projects. Combining data from both sources, we can evaluate evidence-based design, specification, and construction options, enabling our clients to make informed choices and minimise their projects’ emissions.

Achieving the UK’s ambitious decarbonisation targets will not be easy. To stand a chance, the construction industry must eliminate unnecessary complexity and coalesce around a common approach.

This will give professionals the bandwidth to focus on activities that will drive tangible progress. These include collecting, analysing and applying the data that will help us demonstrably decarbonise our built environment.

Adam Mactavish is the group sustainability director at Currie & Brown