Achieving Net Zero Case Study: the UK’s first net zero carbon commercial development

Property developer Landsec is moving forward with plans for what aims to be the UK’s first net zero carbon commercial development. Using innovative building techniques, experts have said that The Forge embodies what the future of construction will look like.

As 40% of the UK’s carbon emissions are attributable to the built environment, the sector needs to be pursuing more aggressive rates of decarbonisation. But there are currently no UK commercial buildings which are considered net zero in both construction and operation, according to the UK Green Building Council’s (UKGBC) net zero carbon buildings framework.

The Forge, previously known as 105 Sumner St, is a 139,000 sq ft office development in LB Southwark which aims to change this. It aspires to be the first commercial building that will be both constructed and operated in line with UKGBC’s framework and associated energy performance targets. Construction has started and is due to finish in 2022.

Picture of what The Forge, the UK's first zero carbon commercial development, will look like.
What the entrance of The Forge will look like. Image courtesy of Landsec.

How do you build a net zero carbon building?

Developing a net zero carbon building means addressing scope 3 emissions. These are the emissions that are a consequence of a company’s actions, but which occur at sources that the company does not own or control directly.

Construction activities account for a large part of the construction industry’s scope 3 emissions. These include: supply-chain emissions that arise from the extraction of resources; manufacturing products; transporting materials; and assembling the building. These are often referred to as ‘embodied carbon’.

The Forge will be one of the most innovative construction sites in the capital. Innovate UK, the UK’s innovation agency, has awarded funding to Landsec, along with tech-led design practice Bryden Wood, and design development and prototyping company Easi-Space, to deliver what will be the world’s first ever office building using a platform-led approach to design and construction.

What’s a platform-led approach and what are the benefits?

The platform system, known as P-DfMA (Platform for Design, Manufacture and Assembly), consists of a set of components that can be combined to produce highly customised structures. This means that different kinds of spaces can be built with just a single ‘kit of parts’. The government has identified this method as key to the transformation of the construction sector.

Landsec, Bryden Wood and Easi-Space led a research and development trial of this approach on a small-scale prototype, at a research centre in Hampshire. You can watch a video explaining the trial below.

The trial had positive results:

  • construction productivity improved by 55%, compared to productivity on a traditional construction site
  • the time it took to install the building was reduced by 30%, compared to using traditional construction techniques
  • the final build achieved 33% cost savings, compared to traditional construction techniques.

The result is a structure that uses less material, creates less waste and has an almost 20% reduction in embodied carbon compared to a traditional build. Further savings have since been made through careful specifications, including high levels of recycled content and cement replacement in the main building materials.

“With its innovative platform technique and ‘kit of parts’ approach [The Forge] embodies what the future of construction will be,” says Sam Stacey, Challenge Director for the Transforming Construction Challenge at UK Research and Innovation. “Such approaches are essential to the transformation of the construction sector.”

How do you operate a net zero building?

Embodied carbon is only a part of the net zero story; operational energy efficiency is also fundamental to achieving a truly net zero carbon building. The Forge uses passive design techniques to reduce the energy demand of the building, and highly efficient air source heat pumps to provide heating and cooling. Once in operation, these will be run on a 100% renewable electricity tariff. An array of photovoltaic panels (solar panels) are provided at roof level. These will offset the annual emergency generator diesel fuel needed for ongoing maintenance.

In order to tackle the ‘performance gap’, the building was modelled using the Design for Performance approach. This allows the team to predict actual energy use and to model different off-axis scenarios to stress-test the system and then finetune it, increasing its efficiency further.

Julie Hirigoyen, Chief Executive at UKGBC, also praised the development: “The Forge is a ground-breaking development and testament to Landsec’s desire to tackle the climate crisis head on. Developers, construction firms, architects and occupiers must start working together at scale to deliver buildings like this that minimise whole life carbon and contribute to meaningful progress in the battle against climate change.”

Lessons for the built environment sector  

In 2016 Landsec became the first property company in the world to adopt a science-based target to tackle emissions and has since launched a five-step plan to become a net zero carbon business by 2030. Using science-based targets will see Landsec reduce absolute carbon emissions by 70% from a 2014 baseline over the next ten years.

And once they complete The Forge, Landsec has committed to building – and operating –  all of its future developments in line with UKGBC’s net zero carbon buildings framework. The hope for the wider built environment sector is that The Forge will act as a ‘demonstrator project’ for other developments, and help make the business case for other developers to commit to more net zero buildings.

Our Achieving Net Zero case studies showcase inspiring examples of best practice, from low-cost interventions to large-scale infrastructure. We want to raise the profile of schemes and organisations doing a great job of working towards the Net Zero ambition, highlighting what we can learn from them.

If you’d like to get involved with our Achieving Net Zero programme, get in touch with Anna Odedun, Head of Knowledge.