Carbon thresholds are changing construction material selection by setting maximum allowable embodied carbon limits on building products, which pushes specifiers and procurement teams to favour materials with lower carbon footprints over those with higher emissions. Regulations, green building certification schemes, and client sustainability requirements are driving this shift across Europe and beyond. The questions below unpack how these limits work, which materials feel the pressure most, and where the rules are heading.
How do carbon thresholds actually work in construction procurement?
Carbon thresholds in construction procurement are maximum embodied carbon limits assigned to building products or whole buildings, expressed in kilograms of CO₂ equivalent per unit of material or per square metre of floor area. When a product’s Environmental Product Declaration (EPD) shows a carbon footprint above the threshold, it either fails to qualify for a project or attracts additional scrutiny from specifiers and clients.
In practice, thresholds operate at several levels. National building regulations in countries such as the Netherlands, Denmark, and France now require whole-life carbon assessments as part of planning approval, with specific limits on embodied carbon. Green building certification schemes add another layer, rewarding projects that use materials below defined carbon benchmarks. Increasingly, large public procurement bodies set their own carbon limits as contract conditions, meaning suppliers must demonstrate compliance through verified EPD data before they can bid.
The verification chain matters here. A threshold is only as meaningful as the data behind it. Manufacturers need independently verified EPDs that reflect actual production conditions, not generic industry averages. This requirement is gradually separating manufacturers who invest in precise measurement from those who rely on conservative estimates.
Which construction materials are most affected by carbon limits?
Concrete, steel, and aluminium face the most direct pressure from carbon thresholds because they are produced at high volume and carry significant embodied carbon per tonne. Among these, concrete draws particular attention because it is the most widely used construction material in the world, and the cement used to bind it accounts for a substantial share of global industrial CO₂ emissions.
Within the concrete sector, standard Portland cement mixes are the most exposed. Their carbon footprint is well documented in EPDs, making it straightforward for specifiers to compare them against lower-carbon alternatives. Precast concrete products, which are manufactured under controlled factory conditions, are well positioned to respond because production parameters can be adjusted systematically, something that is much harder to achieve on a ready-mix site.
Structural timber and cross-laminated timber are sometimes presented as straightforward alternatives, but they carry their own constraints: availability, structural span limitations, fire performance requirements, and the need for careful moisture management. Steel faces pressure too, though electric arc furnace production using scrap metal significantly reduces its carbon footprint compared with primary steelmaking. The net effect is that no single material escapes scrutiny, and procurement teams must evaluate carbon performance alongside structural, durability, and cost criteria.
What’s the difference between embodied carbon limits and operational carbon limits?
Embodied carbon limits apply to the carbon emitted during the extraction, manufacture, transport, and installation of building materials, covering what is often called modules A1 to A5 in lifecycle assessment terminology. Operational carbon limits apply to the carbon emitted by a building while it is in use, primarily through heating, cooling, ventilation, and lighting over its service life.
For most of the past two decades, energy efficiency regulations focused almost entirely on operational carbon. Insulation standards, boiler efficiency requirements, and renewable energy mandates all target the energy a building consumes once occupied. These measures have been effective enough that operational carbon now represents a smaller proportion of a building’s total lifecycle emissions than it once did, which has brought embodied carbon into sharper focus.
The distinction matters for material selection because the levers are different. Reducing operational carbon means designing efficient building services and envelopes. Reducing embodied carbon means changing what materials are specified and how they are made. Concrete manufacturers, for example, have no influence over operational carbon once their product leaves the factory, but they have direct control over embodied carbon through cement content, mix design, and curing methods. Procurement teams now need to address both dimensions separately, using lifecycle assessment tools that distinguish clearly between the two.
How are carbon thresholds pushing concrete manufacturers to innovate?
Carbon thresholds are pushing concrete manufacturers to reduce cement content, adopt supplementary cementitious materials (SCMs), and explore alternative curing methods that lower the carbon footprint of their products without compromising structural performance. The pressure is direct: if a product’s EPD exceeds the threshold set by a specifier or regulator, it loses commercial viability on that project.
SCMs such as ground granulated blast furnace slag and fly ash have been used for decades to partially replace Portland cement. Their appeal has grown as carbon limits tighten, because replacing cement with these materials reduces the carbon intensity of the concrete mix. However, SCMs still require some cement for activation, and their availability varies by region, which limits how far substitution can go in practice.
Carbon dioxide curing is an approach that addresses both cement reduction and carbon storage simultaneously. In this process, CO₂ is introduced into the curing environment of precast concrete, where it mineralises into the concrete structure as stable carbonates. This accelerates strength development, which in turn allows cement content to be reduced without sacrificing early-age performance. The CO₂ introduced during curing is permanently stored in the product, contributing a measurable negative emission that improves the product’s EPD.
We at Carbonaide developed our CO₂ curing system specifically for precast concrete producers operating in separate curing chambers, which is the standard setup for precast production. The Carbonaide CO₂ Curing System integrates with existing or new curing chambers and is managed through the Carbonaide Service Platform, which tracks CO₂ flow in real time and generates the verified carbon storage data needed for EPD updates and carbon credit certification. The result is concrete with a measurably lower, and in some cases negative, carbon footprint, which is precisely what carbon threshold compliance requires.
Should specifiers choose low-carbon concrete or alternative structural materials?
Specifiers should evaluate low-carbon concrete and alternative structural materials based on project-specific structural requirements, carbon performance data, cost, and supply chain reliability rather than applying a blanket preference for one material category. In most mainstream construction projects, concrete with a reduced carbon footprint remains the most practical choice because it meets structural, fire, acoustic, and durability requirements that alternatives often cannot match at scale.
Structural timber performs well in certain building typologies, particularly low-to-medium-rise residential and commercial buildings, but it has span limitations, requires careful detailing to manage moisture, and depends on certified sustainable forestry supply chains. Its embodied carbon advantage over conventional concrete narrows considerably when transportation distances are long or when the building’s structural demands require additional engineered timber components.
Steel, particularly from electric arc furnace production, can achieve a lower embodied carbon footprint than primary steel, but it still carries higher carbon intensity per tonne than concrete with mineralised CO₂ storage. For foundations, ground-floor slabs, retaining structures, and precast infrastructure products, concrete has no practical structural alternative at present.
The more productive question for specifiers is not which material category to choose, but how to specify concrete that meets the carbon threshold. Requiring EPD-verified carbon footprint data, specifying mixes that use SCMs or carbon dioxide curing, and working with manufacturers who can demonstrate measured CO₂ mineralisation all move the needle without requiring a change of structural system. This approach keeps the structural and cost advantages of concrete while meeting the carbon limits that procurement now demands.
Where are carbon thresholds heading in the next decade?
Carbon thresholds in construction are heading toward stricter limits, broader regulatory coverage, and greater standardisation of measurement methods across national markets. The trajectory is clear: limits that were voluntary in 2020 are becoming mandatory, and limits that currently apply to public buildings are extending to private development and infrastructure.
Several European markets are already moving in this direction. Whole-life carbon assessments are becoming standard planning requirements rather than optional additions. Procurement bodies are tightening the maximum allowable embodied carbon per square metre with each revision of their guidelines. At the EU level, the Energy Performance of Buildings Directive and the Construction Products Regulation are both moving toward requiring lifecycle carbon data as a condition of market access.
For concrete manufacturers, the direction of travel means that products without verified EPDs will face growing barriers to specification, and products with high embodied carbon will become progressively harder to sell into regulated markets. Manufacturers who invest now in measurement infrastructure, mix optimisation, and carbon storage verification are building a commercial advantage that will compound as thresholds tighten.
The most significant shift over the next decade may be the move from carbon limits to carbon credits as a parallel mechanism. As regulations require lower embodied carbon, voluntary carbon markets are creating revenue streams for manufacturers who store more CO₂ than regulations require. CO₂ mineralisation in concrete is one of the few carbon dioxide removal methods that is durable, measurable, and integrated into an existing industrial process, which positions it well as carbon credit standards become more rigorous. Concrete manufacturers who can demonstrate permanent CO₂ storage through verified mineralisation data will be able to participate in both the regulated compliance market and the voluntary carbon removal market simultaneously.
