Carbon footprint in construction materials: how to calculate it

If you manufacture or distribute construction materials (concrete, steel, insulation, ceramics, paints, glass, aluminium profiles) it is very likely that in recent months you have started receiving questions about the environmental impact of your products. And if you have not been asked yet, the context ahead will make them inevitable.

The construction sector is in the midst of a profound transformation in sustainability. Large developers, construction companies with sustainable building targets and public tenders are starting to ask for something very specific: verifiable data on the carbon footprint of the materials they buy.

They do not want generic sustainability commitments, they want numbers. And those numbers have to come with methodology and documentation. This article explains exactly what they will ask of you and how to prepare to respond.

Why the construction sector is under pressure

According to the European Commission, buildings are responsible for approximately 40% of energy consumption and around 36% of energy-related greenhouse-gas emissions in the EU. A significant share of those emissions does not come from the building's use, but from the manufacturing of the materials it is built with, which is known as embodied carbon.

This means that a developer who wants to reduce their real footprint necessarily has to look at the materials they use. And that directly affects you if you are a manufacturer or supplier of those materials.

Where the regulatory pressure comes from

The demand is arriving from several fronts at once:

• Construction Products Regulation (EU) 2024/3110: the new regulation (which replaces Regulation 305/2011) integrates environmental information into the declaration of performance and conformity. From January 2026, manufacturers of the first product families with updated harmonised standards (among them concrete, steel and insulation) must declare the global warming potential (GWP) of their products, calculated in line with the EN 15804 standard. The set of environmental indicators will expand progressively up to 2030-2032.
• Energy performance of buildings: the revision of the EU's energy-efficiency rules for buildings and the move towards low-emission buildings also push companies to account for the carbon in materials.
• Digital Product Passport: it will carry the environmental data (including EPDs and carbon footprint) of construction materials in a digital, comparable format.
• Green procurement and certifications: public tenders with environmental criteria and sustainable building labels such as LEED, BREEAM or DGNB already require environmental impact data for materials.

What they will ask of you, exactly

This is where many companies get lost. The request can come in very different forms, but at heart it almost always asks for one of these two things, or both at once.

An EPD (Environmental Product Declaration)

The EPD (Environmental Product Declaration) is the standard document in the construction sector for communicating the environmental impact of a product across its life cycle. It is the equivalent of what in other sectors would be the product carbon footprint, but in a specific format regulated by the EN 15804 standard (based on ISO 14025), which must be verified by an independent third party and registered in a recognised database.

An EPD includes several environmental impact indicators (not just CO₂, but also water consumption, waste generation and resource depletion) and covers the different phases of the product's life cycle: from raw-material extraction to end of life, through manufacturing and transport.

Embodied carbon data for a specific project

Sometimes the client does not ask for a full EPD, but for the emissions data from modules A1-A3 (raw-material extraction, transport to factory and manufacturing) expressed in kg of CO₂ equivalent per unit of product. This is what they need to calculate the embodied carbon of the building they are constructing.

If you have a valid EPD, this figure is already there. If you do not, you will have to calculate it another way, and the credibility of the figure without external verification is always lower.

The life-cycle modules you will be asked for most

The EN 15804 standard divides the life cycle of a construction material into modules. The ones that appear most often in requests are:

• A1-A3 (product): raw-material extraction, transport to factory and manufacturing process. This is the core of what is almost always requested.
• A4 (transport to site): emissions from transporting the material from your plant to the client's construction site.
• C (end of life): demolition, transport and treatment of the material at the end of its useful life. An increasing number of tenders include it.
• D (beyond the life cycle): potential for reuse, recycling or energy recovery. Optional in many cases, but viewed positively.

If you are responding to a request for the first time, focus on A1-A3. It is the minimum scope almost any client accepts and a reasonable starting point for any company.

What data you need to gather to get started

Whether you are going to produce a full EPD or a more basic calculation, the starting data is similar. What you will need, per unit of product manufactured:

• Consumption of raw materials and their origin (how much of each material, where it comes from).
• Energy consumption of the manufacturing process, broken down by energy type (electricity, gas, fuel).
• Transport data for raw materials to your plant.
• Waste generated in the production process and how it is managed.
• Where applicable, packaging and transport data for the finished product.

The usual problem is not that this data does not exist, but that it is scattered across different departments and systems, and no one has consolidated it with a product footprint calculation in mind.

If this sounds familiar, the supplier guide from Manglai covers exactly how to organise this process: which data is essential, which can be estimated in a first phase and how to build a traceable, defensible calculation without grinding your operations to a halt.

Download the free guide

The difference between having the data and having an EPD

Having the data calculated internally and having a registered EPD are not the same thing, and it is important to understand the difference.

An internal calculation without verification can be enough to respond to first client requests, for less demanding tenders or to have a baseline estimate. But for building certifications such as LEED or BREEAM, for public tenders with green procurement criteria, or for clients who need auditable data, a verified EPD is the standard that is expected.

The natural path is to first calculate, then structure the process, and once the calculation is solid and repeatable, take the step of external verification and EPD registration. Trying to produce the EPD without first having the internal process organised is the most expensive and slowest way to reach the same place.

The step that makes the difference

The question is not whether you will have to evidence the carbon footprint of your materials. The question is whether you will be ready when they ask you, or whether you will lose time and opportunities reacting to each request from scratch.

The companies that get ahead do not do so because they have more resources. They do so because they understand that structuring this process once is far more efficient than improvising it every time a new request arrives.

Calculating the life cycle of your materials in line with EN 15804 and keeping that data ready for each request is exactly what Manglai's product footprint solution makes possible.

Download the free guide