The Importance of Part Z

The proposed Building Regulations amendment ‘Part Z’ and Approved Document Z outline requirements on the assessment of whole life carbon emissions and limiting of embodied carbon emissions, for all major building projects. The proposal introduces mandatory assessments ahead of setting carbon limits, giving time to converge on robust yet ambitious targets.

The Approved Document Z is aligned with the Royal Institution of Chartered Surveyors (RICS)' Professional Statement ‘Whole life carbon assessment for the built environment’ and guidance and recommendations made by the Royal Institute of British Architects (RIBA), the Institution of Structural Engineers (IStructE), the Chartered Institution of Building Services Engineers (CIBSE), the UK Green Building Council (UKGBC) and the London Energy Transformation Initiative (LETI).

If adopted, it would rapidly accelerate the voluntary action occurring across our industry, leading to green investment and green jobs creation across construction. The need to introduce carbon regulation is supported by industry leaders and called for by the Climate Change Committee. It is hoped that Part Z will be seen as an ‘easy win’ for the UK’s roadmap to Net Zero.

In my role as Senior Sustainability Consultant and Circular Economy Leader at Max Fordham, I am a firm supporter of Part Z. To contribute to the conversations about embodied carbon, retrofit and material efficiency, I joined New London Architecture (NLA)’s chair Peter Murray for his interview series with industry personalities.

Read the interview below or watch the video:

Max Fordham has been at the forefront of low carbon design ever since the firm was started. As the industry is becoming more aware of reducing embodied carbon, how does your role fit into the work of the practice?

At the heart of our partnership is our commitment to tackle the climate and biodiversity emergency our world is facing. This requires integrated design thinking, in its true sense, and finding solutions that are both viable and sustainable over the longer term.

Max Fordham's Sustainability Team is multi-disciplinary – ranging from architecture, structural design, material science and wellbeing. I have a background in architectural technology, specialising in sustainability. I joined Max Fordham in 2020, after having worked at BRE for over 10 years during which I had the opportunity to work with brilliant scientists in the areas of materials, energy efficiency, BIM and occupational psychology. Prior to that I was involved in designing and delivering low carbon projects in India. I have always been inspired by creating buildings that truly express what they are intended for – physically and environmentally comfortable spaces for people. Materials are the means that help architects deliver this vision.

Today, I'm overseeing our circular economy and embodied carbon service, as well as leading a number of net zero carbon projects.

It is too often the case that material efficiency and low embodied carbon aspirations are not prioritised during design development. Can you explain the reasons behind that, and how one could integrate these requirements?

Over ¾ of emissions over the lifetime of a building come from material use alone. The construction industry is well aware of the environmental impact of material production and has been working to address this. However, the rate of change needed is urgent – in particular for the UK concrete and steel industries. Only China imports more wood than the UK. We need to rethink how we create green jobs in UK manufacturing by stimulating demand for sustainable building products.

The major constraint on reductions to embodied carbon is that there is currently no requirement within Building Regulations, or within National Planning Policy, for emissions to be measured, reported or reduced. It doesn’t always form part of the client brief. We have EPDs (Environmental Product Declarations) for about 10,000 products, and there is a requirement from the supply chain sector to provide this information. Moreover, there's a skills shortage in creating the quantum of EPDs in a shorter timescale. There's an industry consensus that to meet the 2050 net zero emissions target, we must regulate embodied carbon. Major professional bodies are providing guidance to support design thinking and delivery process. Embodied carbon and resource efficiency is not a peripheral hobby matter anymore - the industry as a whole needs to upskill and collaborate to reduce the environmental impact of construction materials.

Client brief is key – we are working with clients in giving a clear brief for optioneering and demonstrating value from concept design stage. Project teams need to radically think about products we specify, how we price them and how they are installed. Also, the industry needs to step up to deliver low embodied carbon alternatives.

You carry out circular economy and embodied carbon evaluations, something the industry is starting to consider. What are the key lessons you have learnt so far from your work?

• Reduce material demand - Form factor optimisation not only reduces heat loss, but material demand as well.
• Know what you have in hand - A meaningful pre-demolition/ material survey before strip-out is needed. There is still a gap between design ambitions, expectations on commercial return, and incorporation of second-hand materials.
• Engage - We are engaging contractors as part of our working practice to understand what has worked and actively working to develop scalable solutions. In one of our recent projects, the contractor managed to divert 200+ light fittings that would have gone to landfill otherwise. We have reused them in a retrofit project that is aiming for Passivhaus standard and uses natural insulation to improve fabric efficiency.
• Manage risk - With circular material management, managing risk is key – i.e. where to focus effort and how to procure to enable reuse. Early market engagement is key to understand where to source materials from and how to deliver cost effectively.
• We need better data! One can do the carbon analysis, but the results vary significantly. We need better datasets on environmental impact of individual products and to regulate embodied carbon. In addition, we should also look at the wider environmental impact (e.g. biodiversity loss) alongside carbon metrics.
• Go digital - Buildings and recycling centres are material banks. We need digital information that can map resource availability. Within our practice, we are actively incorporating material and asset information that can enable maintenance and longevity of services.

Refurbishment and retrofit is a considerable component of construction industry delivery. How do you think this sector can adopt circular economy approaches?

Approximately 60% of construction output is new build, while 40% is refurbishment and maintenance. The demolition sector output is about £1bn and has a huge potential to support the delivery of circular economy. Design teams need to engage with this sector!

There are practices who are redefining how we perceive aesthetics, minimal finish that allow materials to speak for themselves (e.g. rammed earth or timber). New low carbon products are emerging and social enterprises enabling reuse are growing as well. So think twice before you put together your demolition work package.

We need to not only modernise how we make buildings but also how we demolish them! The Government Green Jobs Task Force estimates there is potential to create over 200,000 low carbon jobs, between now and 2030. But the skills shortage to enable net zero carbon economy is a massive challenge. So, why not target 10% of new low carbon jobs creation to develop a supply chain that enables material reuse, material testing and creates the digital infrastructure for a new circular economy market? This will give the confidence needed by the industry in specifying products with assurance of performance and a supply chain that can meet the demand. Local authorities with huge procurement power are ideally placed to enable local material share hubs and require project teams to actively seek to reuse on-site/off-site as part of the procurement process.