Carbon Offsetting

Carbon offsetting is a purchase of greenhouse gas reductions made by another project, counted against your own emissions. It can also buy removals. Examples are reforestation, a renewable energy installation or a methane capture scheme. The buyer's own footprint does not shrink. What the buyer holds is a carbon credit, a unit that normally stands for one tonne of CO2 equivalent. EU Regulation 2024/3012, for example, defines a certified removal unit as one metric tonne of CO2 equivalent of certified net benefit.

What is carbon offsetting in a building project?

In a building project, offsetting is a step that comes after the calculation. A client or developer works out the remaining emissions, for example the embodied carbon of materials and construction, and then pays for credits against that figure. The credits are a separate transaction. They change nothing in the design, the structure or the calculated result.

How is carbon offsetting different from reducing embodied carbon?

The two are often mixed up because both appear in the same sustainability reports. Reducing embodied carbon changes what the building is made of and how it is built, so the emissions never occur. Offsetting leaves the building as it is and pays for emissions to be avoided or removed somewhere else. Only the first lowers the number that the building itself causes.

Question	Reducing embodied carbon	Carbon offsetting
Where the change happens	Inside the building: materials, structure, transport and site works	Outside the building, in a project the buyer does not control
Effect on the calculated figure	Lowers it	Leaves it unchanged
When it can be done	In early design, while material choices are open	Only once the remaining emissions are known
What is checked	The life-cycle calculation of the actual design	The credit and the project behind it
Risk of reversal	None once the material is not used	Stored carbon can return to the atmosphere

What does the EU rule on offset claims say?

The clearest legal line comes from Directive (EU) 2024/825 on empowering consumers for the green transition. It amends the Unfair Commercial Practices Directive 2005/29/EC, which covers unfair business-to-consumer commercial practices. The new point 4c in Annex I to that directive adds one practice to the list of those that are always unfair. The practice is a claim of a neutral, reduced or positive greenhouse gas impact for a product. It is banned when the claim rests on offsetting.

Member States had to adopt the national measures by 27 March 2026. They apply those measures from 27 September 2026 (Article 4(1) of the directive). The directive covers commercial practices aimed at consumers. A claim made only to business clients is outside it.

Recital 12 gives the reason. Claims such as "climate neutral", "carbon positive", "climate compensated" and "reduced climate impact" may only rest on the actual lifecycle impact of the product. A claim based on offsetting outside the value chain is not equivalent. The recital says that "product" means a good or a service.

Such a prohibition should not prevent companies from advertising their investments in environmental initiatives, including carbon credit projects, as long as they provide such information in a way that is not misleading and that complies with the requirements laid down in Union law.

That sentence matters for design studios. Naming a carbon credit project as an investment is allowed. Implying that the building itself is neutral because of the credit is not.

Are carbon offsets reliable?

Quality is the main debate about offsets. A credit pays for a result that nobody can observe directly, so a buyer has to test the project behind it. EU Regulation 2024/3012 sets up a voluntary certification framework for carbon removals and soil emission reductions. Its recitals describe the same tests that a careful buyer applies to any credit.

Question to ask	Why it matters
Would the reduction have happened anyway?	An activity should go beyond standard practice and beyond what the law already requires. If it would happen without the credit income, the credit pays for nothing new. This is additionality (recital 20).
Will the stored carbon stay stored?	Carbon that is captured and stored risks being released back into the atmosphere from natural or human causes. This is reversal, and it needs monitoring (recital 22).
Has the same tonne been sold twice?	Fraud can include more than one certificate for the same activity. A registry that tracks each unit reduces the risk of double counting (recital 36).
Is the baseline realistic?	The benefit is counted above a baseline, so the baseline must reflect standard performance in similar conditions (recitals 14 and 21).

A logo or a sticker proves very little on its own. Ask for the project documents and the registry entry for the credit.

Can a building be carbon neutral by buying offsets?

A building can be paired with offsets, but that does not make it a low-carbon building. A sound sequence is to calculate the whole-life figure and reduce it in design. Then report any credits separately, naming the project, the registry and the year. Offsets cannot stand in for design choices that were never made.

Before you write "net zero" in a brief or a marketing text, check how the client or the net-zero carbon building standard defines it. If the wording is aimed at consumers, point 4c may apply to it.

How does the EPBD measure whole-life emissions?

Directive (EU) 2024/1275, the recast Energy Performance of Buildings Directive, defines whole-life-cycle greenhouse gas emissions in Article 2, point 24. They are the emissions that occur over the whole life cycle of a building. The definition includes the production and transport of construction products and construction-site activities. It also includes the use of energy in the building and the replacement of construction products. The last items are demolition, waste transport and management, reuse, recycling and final disposal.

Under Article 7(2), Member States must ensure that the life-cycle global warming potential is calculated under Annex III. They must also ensure that it is disclosed in the energy performance certificate. The dates are 1 January 2028 for all new buildings with a useful floor area larger than 1 000 m2, and 1 January 2030 for all new buildings.

The definition lists contributions along the life cycle and does not mention credits. The calculated figure therefore stands on its own. Any offset belongs beside it as a separate disclosure. A life-cycle assessment of the design produces the figure that offsets are meant to balance, so it comes first.

How should a practice describe offsets to clients?

1. Calculate the building's emissions first, and state the method and the system boundary.
2. Show the reductions made in design, with their figures and sources.
3. Report any offset as a separate purchase: project name, registry, year and tonnes.
4. Avoid words such as "neutral" or "positive" when they rest on credits and the client will pass them to consumers. Directive 2024/825 treats that wording as an unfair practice.

Offsetting is a financial step at the end of a project. It does not replace the material and design decisions that lower the emissions of the building itself.