From 1 January 2027, every tonne of steel, cement, and aluminium imported into the UK will carry a new kind of price tag: a carbon one. The UK's Carbon Border Adjustment Mechanism, or CBAM, is coming, and for an industry that depends heavily on imported materials, its implications are significant.[1]
The principle is straightforward. UK manufacturers already pay a carbon price through the Emissions Trading Scheme. Overseas producers, in many cases, do not. The CBAM is designed to level that playing field by placing an equivalent carbon cost on imported goods from emission-intensive sectors. For construction, three of the five sectors in scope are foundational: steel, cement, and aluminium.
How It Works
Any business importing more than GBP 50,000 of CBAM goods over a 12-month period will need to register with HMRC as a CBAM declarant.[2] They will be required to submit returns detailing the weight, commodity code, embodied emissions, and country of origin of every consignment. The charge itself is calculated by multiplying the imported embodied emissions by a government-set CBAM rate, minus any carbon price relief where the exporting country already applies its own carbon pricing.
The first accounting period runs the full calendar year of 2027, with returns and payments not due until 31 May 2028. After that, the system moves to quarterly reporting.[1] Importers can use either actual emissions data from their supply chain or government-published default values. In practice, those who invest in accurate supply chain data will likely pay less, because default values tend to be conservative.
Why Construction Should Pay Attention
Steel and cement are the backbone of construction. The UK imports substantial volumes of both, and the carbon intensity of these imports varies enormously depending on their country of origin and production method. A tonne of steel from a country with minimal carbon pricing will attract a higher CBAM charge than the same product from a jurisdiction with equivalent pricing to the UK ETS.
For contractors and quantity surveyors, this has direct cost implications. Procurement decisions will increasingly need to factor in not just unit price and lead time, but carbon intensity and country of origin. Sourcing purely on price may become more expensive once the CBAM charge is applied. Firms already tracking embodied carbon for sustainability reporting will find themselves better positioned than those starting from scratch.
This also intersects with the broader Construction Products Reform White Paper, published in February 2026, which proposes mandatory digital product information and unique product identifiers for all construction products.[2] The direction is clear: the days of opaque supply chains in construction are numbered.
The Data and AI Opportunity
CBAM compliance will demand something that construction has historically struggled with: granular, verifiable data flowing through the supply chain. Importers will need to track embodied emissions per consignment, maintain records for six years, and submit detailed quarterly returns to HMRC.
This is where technology can make a genuine difference. AI-powered tools are already being used to map supply chain emissions, cross-reference Environmental Product Declarations, and flag anomalies in reported data. For quantity surveying firms, integrating carbon cost modelling into early-stage cost planning will become a competitive advantage. The firms that can tell a client not just what a project will cost in pounds, but what it will cost in carbon and associated levies, will be the ones winning work in 2027 and beyond.
But as with any AI deployment, governance matters. Carbon data is only useful if it is accurate, traceable, and subject to verification. ISO 42001 provides a framework for responsible AI management, and any firm using automated tools to calculate or report CBAM liabilities should ensure those tools meet appropriate standards of transparency and auditability.
Preparing Now
January 2027 is nine months away. That sounds like plenty of time, but for firms that need to audit their import volumes, engage with overseas suppliers on emissions data, and build internal reporting processes, it is not as comfortable as it seems.[1]
The practical steps are clear. First, map your exposure: which of your regularly imported materials fall within CBAM scope, and from where? Second, assess whether you cross the GBP 50,000 threshold. Third, start conversations with key suppliers about the emissions data they can provide. And fourth, consider how your cost planning and procurement processes need to evolve to account for carbon costs as a material input, not an afterthought.
The CBAM is not a burden to be absorbed. It is a signal that the economics of construction are changing. Those who treat it as an opportunity to build more transparent, data-driven supply chains will find themselves ahead. Those who wait will find themselves paying more, both in carbon levies and in lost competitiveness.
