CPW supports Part Z – legislation is the only way

Following the Carbon Emissions (Buildings) Bill being brought back to the House of Commons for a second reading, our Director Dr Stephen Ball explores the potential impacts of Part Z, the amendment on which the Bill is based, being incorporated into UK Building Regulations.

The built environment is currently responsible for 25% of total UK greenhouse gas emissions, according to the UK Green Building Council. Our industry has a huge role to play in reducing UK carbon emissions, and while many of us are already working to existing standards and targets from professional bodies such as RICS and RIBA, legislation is the only way to make a significant impact on the sector. We need Part Z.

Part Z is an industry-proposed amendment to UK Building Regulations which would introduce mandatory reporting of carbon emissions in the built environment as part of a comprehensive whole life carbon assessment, as well as limiting embodied carbon emissions on construction projects.

Operational vs embodied carbon

But what do we mean when we talk about whole life carbon? Whole life carbon looks at the total emissions from a construction project, from cradle-to-grave (also known as the building life-cycle). This is made up of operational carbon and embodied carbon.

Operational carbon refers to the carbon that’s emitted while the building is in use, such as through heating, cooling, lighting, ventilation and equipment/processes. This is easily measured. Until recently, operational carbon has been responsible for the majority of building emissions. However, with the rise of low carbon energy solutions, energy-efficient designs and the decarbonisation of the grid, operational carbon emissions are dropping.

Embodied carbon, on the other hand, is the carbon that’s emitted in the production and demolition of a building, including the extraction and transportation of materials. Embodied carbon emissions now make up more than half of the total carbon emitted across a building’s expected lifetime. However, this is more tricky to measure. You need to rely on manufacturers, suppliers and contractors accurately measuring and reporting on emissions at each stage of the process.

Supply chain considerations

While we completely support Part Z and believe the time for action is now if we are ever going to meet the UK Net Zero targets, we need to consider the role of the supply chain.

Do we really believe international supply chains are at a stage where they would be happy to measure and report on their embodied carbon? What is their motivation to meet UK standards? Will there be a process for checking the accuracy of this reporting?

We need to be realistic about the extent to which we can influence practices in other countries. Perhaps this will impact product availability and cost. Perhaps this is an opportunity for British industries that work to these standards to thrive – time will tell.

Competitive construction laws

Though we may not be able to influence suppliers abroad, our construction colleagues in other countries are ploughing ahead. Currently, we are at risk of falling behind. Denmark, Finland, France, the Netherlands and Sweden have already passed laws to regulate whole-life carbon emissions from buildings. The European Commission is also considering a proposal which would require EU member states to report on whole-life carbon for new buildings as of 2030.

The London Plan already requires whole life carbon assessments to be undertaken as part of the planning application, which is a great move in the right direction, but the rest of the country mustn’t be left behind.

For the UK building sector to remain a big player in sustainable construction, we need to ensure our legislation is keeping pace.

Achieving a circular economy

Sustainability it at the heart of what we do at CPW. A key vision for us for the future is to work towards a circular economy. Part Z will help us achieve this.

It’s time we stop the smash. In the future, building with sustainable materials and using sustainable energy sources will not be enough – we will need to stop demolishing buildings and sending vital resources to landfill. In order to do this, we need to start designing with the view that the materials will need to be removed and reused at the end of the usable life of the building. We need to plan for extraction methods that don’t damage resources and ensure clients are on board with how this may affect timelines.

Implementing Part Z will increase the motivation to use reclaimed and recycled materials by rewarding the reduced embodied carbon output of the building materials. Nothing motivates you more than the risk of not being granted planning permission. Without this, it’s a hard sell to encourage clients to utilise second-hand materials that may take longer to source or to consider alternatives to demolition that may be more costly or time-consuming.

Towards legislation

Part L, which seeks to reduce operational carbon through the conservation of fuel and power, has been so effective at improving energy performance that a similar intervention for embodied carbon will almost certainly help to tackle the lifetime carbon emissions of buildings.

In June 2022, Part Z took the first steps towards legislation as MP Jerome Mayhew introduced the Carbon Emissions (Buildings) Bill to Parliament. With the second reading of the bill stalling, it is time again for the industry to show our support for this amendment to ensure all carbon emissions are taken seriously and not just those that are more easily measured.

MP Jerome Mayhew in his speech addressing the House of Commons highlighted that embodied carbon in construction represents 50 million tonnes of emissions each year, greater than the emissions of all the United Kingdom’s aviation and shipping industries combined. These are figures we cannot ignore; we need action in our industry.

Without legislation, all work towards whole life carbon targets and recommendations becomes purely academic. We await further embodied carbon discussions in the House of Commons. We are hopeful for change.

Find out more about CPW’s mission to deliver zero carbon buildings for a better future.