The construction industry is no stranger to change. In recent years, however, it’s faced a particularly confusing one: an uncoordinated surge in local authority planning requirements for embodied carbon. These efforts, driven by good intentions and aiming to fill the vacuum left by a lack of central regulation, are starting to reveal the cost of this patchwork approach.

Across the UK, nearly two thirds of local authorities now mention “embodied carbon” in their planning documents. That might sound like progress. But dig deeper, and the picture becomes more complicated. Only 20% mention measurable Whole Life Carbon Assessments (WLCAs), and each of these sets of requirements have been individually developed [reference]. The result? A growing web of inconsistent rules that’s placing an increasing burden on developers, consultants, and contractors alike.

This is a classic case of policy fragmentation: councils are acting in isolation because national government has not. One authority might require a WLCA for developments over 1,000m²; another might set the bar at 500m². One sets the limit at 150 homes. Another at 15 homes. Or maybe 5. Another says the requirements only count if you’re developing more than five hectares of land. It all depends where you’re building. Different methodologies are being referenced too – some use LETI targets, others reference RICS, BREEAM, or bespoke toolkits. What was once a shared national challenge is now being tackled with a variety of local interpretations.

The consequences are significant. Companies operating nationally are compelled to familiarise themselves with new rules for every project situated in a different local authority. Major housebuilders, who often replicate the same house designs hundreds (or thousands) of times across the country, may sometimes need to assess embodied carbon, sometimes not, and with varying scopes and targets. I’ve even heard rumours of some developers prioritising developments in certain authorities over others, merely to avoid extraneous paperwork.

This patchwork approach also disadvantages smaller developers and local councils themselves. Large clients with in-house sustainability teams can navigate this landscape; SMEs often cannot. Meanwhile, overstretched planning officers are asked to assess technical submissions that vary in scope and quality from what their neighbouring counterparts are undertaking, with no central training or data against which to benchmark them. It’s a recipe for inconsistency—and one that risks undermining public trust in net zero goals.

Ironically, this messiness is not born of apathy. Quite the opposite. Councils are acting to reduce the nation’s embodied carbon footprint, because central government isn’t. But their piecemeal efforts only reinforce what many in the industry already know: we don’t need more policy; we need more consistent policy. And that means national regulation.

Embodied emissions from construction materials and processes account for over 10% of the UK’s total emissions. More than aviation and shipping combined. Yet there are currently no legal limits on these emissions, and no regulatory requirement to measure them. This needs to change.

The good news is that the groundwork for national regulation has already been laid. The UK Net Zero Carbon Buildings Standard, currently released as a pilot version, has garnered support from across the built environment. Notably, 200 projects are now undertaking formalised pilot testing of the Standard, and 350 expert volunteers have contributed to its creation over two years. It’s a standard developed by the industry, for the industry – and it sets out precise rules for the measurement and reporting of embodied carbon (alongside other metrics), along with limits that projects must meet if they wish to demonstrate compliance.

Alongside it, the proposed Part Z amendment to the Building Regulations offers a ready-to-go policy mechanism. It calls for mandatory Whole Life Carbon Assessments at design and completion stages, and a phased introduction of embodied carbon limits. The proposal is pragmatic, aligned with industry standards like RICS and LETI, and has been endorsed by a broad coalition of firms, trade bodies, and built environment professionals. More than 200 organisations have so far written in support of such regulation.

Meanwhile, other countries are not waiting. The European Union has updated the Energy Performance of Buildings Directive, requiring the reporting of embodied carbon from 2028, and introducing limits two years later. Several European countries, such as France, the Netherlands, Denmark, and Sweden already have such regulations in place. Even major US states are leading on this, despite uncertainty around climate at the federal level.

Maybe it’s fear of complexity that’s holding the UK back. Maybe there’s a preconception that regulation is never desirable. But on this topic, the evidence shows that the opposite is true. Voluntary action has already proven the feasibility of this regulation. The private sector is measuring embodied carbon at scale. WLCAs are embedded in planning processes across the country. Tools like the RICS Professional Standard, or the IStructE’s Structural Carbon Tool are already widely used. We are not starting from scratch. We’re finishing the job.

Councils don’t want to invent bespoke policies; they want consistency. Developers don’t want to navigate 400 different sets of planning requirements; they want a level playing field. And planners don’t want to become carbon accountants; they want clear standards they can point to in policy and practice. This is where Part Z comes in. It’s not just a technical amendment. It’s a signal – to industry, to investors, and to the public – that the UK is serious about delivering net zero in the built environment. It gives us a framework for action, a mechanism for enforcement, and a shared language for progress. And it just so happens to stop the industry wasting time and money keeping up with a plethora of ever-diverging local requirements.

Let’s turn this patchwork of local ambition into a national commitment. Let’s back Part Z, and build a future we can all be proud of. Please head to www.part-z.uk/industry-support to add your company’s support.