Great Portland Estates – BNG and Embodied Carbon

Great Portland Estates plc (GPE) commissioned Greengage to help set a biodiversity net gain and embodied carbon KPI, baseline, and strategy. This was incorporated along with one other sustainability related KPI within the first ESG-linked revolving credit facility to be issued by a UK REIT.

Greengage’s input forms a fundamental part of the overall strategy for the GPE sustainability ambitions. The four pillars of the “The Time is Now” sustainability commitment made in May 2020 set out requirements to:

  • Decarbonise to become net zero by 2030
  • Design climate change resilient and adaptable spaces
  • Create a lasting positive social impact in communities
  • Put health and wellbeing front and centre of the group’s operations

Embodied Carbon

With worldwide carbon budgets rapidly depleting, the carbon associated with development up to practical completion is a huge challenge for the construction industry to remedy. However, with poor available data and a sporadic understanding within supply chains, fully measuring the impact of development and setting strategies for improvement is challenging.

LETI Embodied Carbon Primer – Breakdown of carbon emissions across lifecycle

Greengage undertook a review of the embodied carbon performance of multiple GPE developments, currently under construction in central London. As part of this review we worked with various stakeholders in the construction of the building, including the design team, contractor, and suppliers. Our work aimed to:

  • Establish an Embodied Carbon Baseline for current GPE projects through an understanding of materials quantities.
  • Assess the level of accuracy of information provided.
  • Identify the availability of data in the current design and construction process.
  • Understand where the significant savings in embodied carbon need to be made in order to achieve future targets.

Following this Greengage worked with GPE to set out interim targets for reducing embodied carbon across their upcoming design and construction projects, over a 10 year programme. As part of this targeting the ‘big-hitters’ to make rapid reductions, especially around structural design.

Our work showed that GPE are already leading performance in embodied carbon, maximising opportunities for the use of BIM, reusing existing structure and façade, and working with educated and proactive design teams and contractors.

Biodiversity Net Gain

To undertake this assessment, Greengage firstly assessed the biodiversity and ecosystem service delivery baseline of GPE’s existing assets. This allowed for actions to be prescribed for each asset to enable predicted uplifts in both biodiversity units and ecosystem service provision to be calculated. Both baseline conditions and predicted changes were measured using the DEFRA Metric 2.0 methodology and a bespoke qualitative assessment for ecosystem service delivery. GPE are a member of Wild West End and therefore it was also key to ensure that methodology aligned with criteria from the Wild West End functional matrix for the quality of green spaces.

Greengage also proposed interventions for each property which if implemented will lead to significant uplifts in biodiversity units and ecosystem service delivery including the provision of habitat connectivity, water management and air quality improvements.

An annual review of biodiversity net gain across the GPE portfolio will be undertaken to enable the measurement of progress year on year against the targeted percentage uplift, which will be disclosed to its lenders and also reported publicly.

“The Time is Now to create climate change resilient spaces. With Greengage’s support we have been able to create firm baselines for our embodied carbon and biodiversity net gain KPIs against which we can measure our performance as we look to decarbonise our business and create climate change resilient spaces. These KPIs will not only support our improved performance, but will drive change in our supply chain and help improve health and wellbeing for our local communities.” Janine Cole, Director of Sustainability