How Life Cycle Assessment will help us ‘Build Back Better’

How Life Cycle Assessment will help us ‘Build Back Better’

How Life Cycle Assessment will help us ‘Build Back Better’ 2000 1428 Greengage Environmental

As we begin to emerge from the COVID-19 lockdown there is a growing call that we ‘build back better’.  One of the steps to ensure this is to take a holistic, whole life approach to designing developments with a reduced overall carbon footprint. To do this, we must start to engage fully with the process of the Life Cycle Assessment (LCA). 

What is Life Cycle Assessment?

LCA is a method for quantifying the environmental impact of processes and products during their life cycle. This methodology can be used to determine the embodied carbon associated with the stages as detailed in the figure below.

The LCA takes into account the total equivalent carbon emissions of all materials within a development, from raw building material extraction (Stage A1) to its eventual disposal (Stage C4) and potential end of life applications (Stage D).

The EN 15978 system boundaries, demonstrating the stages constituting a whole life carbon assessment (source: LETI Embodied Carbon Primer)

Have we not been doing it before?

The life cycle impact of building materials has been assessed for some time using the BRE’s simplified Green Guide Rating system, however the completion of a quantified embodied carbon assessment was, until recently, far from common practice. An increased industry understanding of the environmental impacts embodied within the materiality of buildings, alongside the release of BREEAM New Construction 2018 and the impending adoption of the new London Plan, has led to an increase in the application of LCA’s to better understand the embodied carbon associated with new developments.

Greengage has noted this significant increase in demand for completion of LCA’s on projects. The value realised from the process can vary significantly dependent on how early in the design process the exercise is completed and the ability of a design team to make significant design changes in response to the results.

The value of undertaking an LCA

Firstly, it enables design teams to quantify the embodied carbon associated with their building and subsequently put in place steps to reduce this. Examining individual components of a building at the early design stages can offer benefits such as driving material innovation, identifying opportunities for modern methods of construction and highlighting potential for material reuse and resource efficient design which can deliver subsequent cost savings.

Accounting for embodied carbon can also make a valuable contribution as part of a business’s CSR reporting, demonstrating a greater level of accountability in addressing this critical element in the pathway toward net zero.

In practice, the critical factor to realise the potential benefits identified above is engaging with the LCA process at the earliest opportunity in the design stage. However, it is also worth noting that while completing an LCA represents good practice in fully understanding the environmental impacts of a development, unless practical steps are taken to utilise the LCA data, then the benefits can be limited. This outcome is most common in scenarios where an LCA is being undertaken for compliance and there is limited enforcement of the outcomes. While the exercise is typically completed at the pre-planning the level of engagement with the results can be limited.

In contrast, Greengage are working with a range of clients who are proactively reviewing existing building stock and future developments to identify the most effective options for reducing embodied carbon within their buildings. To maximise the benefits available to a project this not only requires the LCA to be completed at the earliest opportunity but also requires a structured approach and buy-in from the client and design team. This joined up strategy allows a wide range of building design and material options to be modelled and reviewed to understand the full scope of impacts of design decisions.

To maximise the value of undertaking an LCA it is therefore critical to both undertake the exercise during the concept design phase and also in a practical and structured process that allows the whole design team to provide practical input toward developing the optimum design solution with embodied carbon as a key consideration.

A number of accredited bodies and independent organisations have produced practical guidance and methodologies for addressing embodied carbon in developments and act as a valuable resource:

In addition to the above guidance, a number of software providers offer tools to simplify the process. Greengage are actively engaged with these organisations and have developed significant experience which is allowing us to optimise the process of reducing embodied carbon in developments.

If you would like to talk to Greengage about any of the above please get in touch with Greengage Associate Rob Miller.