From a triangle to a square – how construction is evolving

Time, cost and quality – the three essential components of the tried and tested construction triangle form the basic foundation for many a construction project or building. Intrinsically linked, it’s not possible to adjust one without affecting the other two – reduce costs and the quality of the building will be reduced; increase time and the increase in costs will (hopefully!) enhance the quality of the final product.

This construction triangle has worked for many decades but we now have a new kid on the block that’s disrupted the equilibrium – carbon. Although most of us agree it’s time to welcome the shape’s evolution, by factoring in carbon, questions remain over its impact on the other components. For example, lower carbon-intensive materials may take longer to produce or install, which could impact the length of a project. And given the financial hardships the industry has suffered, specifically over recent years, ensuring cash flow remains the primary concern of our clients. Therefore, it’s not surprising we’re continuously asked – how much more will lower carbon cost?

There are several things we need to consider before answering that question.

Where the industry has decades of data to inform its decisions concerning cost, we lack a rich history of carbon data. So, what are the challenges with acquiring more of it?

Availability of data

Currently, we don’t yet have a fully comprehensive set of carbon figures for all the construction materials we use. But the good news is that this is constantly improving. We currently hold 34,000 product Life Cycle Assessments (LCAs) and Environmental Product Declaration (EPDs) in the product database section of the Built Environment Carbon Database (BECD) that date back to 2012. These have been curated by an outside source – sustainability experts Circular Ecology. The good news is that their analysis reveals we’re beginning to see a higher percentage of EPDs being manufactured in recent years. It’s worth noting that EPDs are expensive for manufacturers to produce, a significant barrier to the industry acquiring more carbon data.

BCIS has made significant headway aligning the data with a new materials classification system that falls into Main Categories and Main Building Materials, as shown in the charts below.

Quality of data

Since analysing the data in the BECD, we have observed:

• Even mandated fields aren’t always completed in EPDs.
• Assumptions made within EPDS are often inconsistent, which creates issues if comparing one with another.
• Although the data is verified by a third party, they may lack experience in verifying particular materials.
• Sometimes the source provider has attempted to change the functional unit – this can often lead to more inconsistencies, in terms of how they’ve translated the data and arrived at their calculations.
• In some cases – for example, the Embodied Carbon in Construction Calculator (EC3) – the data is uncertainty adjusted. This means the number reported doesn’t always match to the EPD, which creates problems in translating the data.

Undoubtedly, the biggest impact on ensuring good quality carbon data is the inconsistency of units of measure. For example, some EPDs report carbon numbers per metre squared, or per millilitre. This makes it hard to compare one item with another, without undergoing a longwinded process of translating the data and converting it.

In addition to this, some of the manufacturers will produce one EPD to cover all their products – understandable, given the cost. But this means we need to translate the EPD in several ways to arrive at a unit of measure that will make it easier to compare different products and materials.

Volatility of data

In the cost world, volatility is understood as rapid changes in prices, which we’ve seen over the last four years, especially.

Carbon can experience volatility too, although to a lesser extent. Therefore, it’s important to ensure that your carbon data is regularly updated as EPDs are subject to change. Here’s why:

• Manufacturers change processes to ensure the production of materials has a lower environmental impact, as they realise this is becoming a bigger consideration for the market.
• Decarbonisation of the grid will have an impact on the carbon emissions of certain construction projects that use electricity.
• EPDs expire and can be revised, which means it isn’t possible to rely on the expiry date alone.
• Sample sizes are rapidly changing due to the increase in the amount of EPDs being manufactured. This means the carbon numbers specified in the design stage of the product could also change as the project progresses.

It’s important to ensure the most up-to-date carbon data is reported on a construction project, especially as carbon audits become more prevalent. Otherwise, companies could find themselves accused of greenwashing.

Now we’ve examined the challenges, let’s aim to answer our original question – how much will it cost to balance cost and carbon?

Whether an architect, engineer or designer, we need to speak the same language around specifications, from the start of the design process – ideally armed with the same pieces of information.

The most efficient way to measure and report carbon is to link it to measurement processes that already exist on construction projects – cost estimating, cost reporting and cost control. These typically fall under the remit of cost consultants and quantity surveyors.

It’s not a straightforward process but it’s possible to align cost and carbon by reusing existing cost measurements to help us identify carbon numbers. Currently, the product section of the BCIS Cost and Carbon Database – part of our new service, the Life Cycle Evaluator – holds more than 9,200 materials. 70% of these contain carbon data, with verified EPDs and LCAs and this is continuing to grow and improve in quality.

The service isn’t intended to be a doctrinal tool that strongarms, pressures or shames anyone into reducing their carbon emissions. Rather, it’s intended to serve industry professionals who want a streamlined and efficient process that ensures they can balance their cost and carbon choices more effectively. And until whole life embodied carbon reporting is mandated, it’s likely that cost will remain the main priority driving people’s decision making – not least as many businesses and contractors continue to see their profits squeezed, due to high borrowing costs and inflation.

However, as governments worldwide continue to tighten building regulations to improve energy efficiency, it’s wise to factor this into design choices from the outset. Indeed, there is also increasing evidence that upfront investment in energy-efficient technologies, and more sustainable materials, could lead to lower operational expenditure and increased life cycle longevity.

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