From Green Claims to Green Evidence

What the EU’s new anti-greenwashing rules mean for real estate developers and owners

27 September 2026 marks an important change in the way environmental and sustainability claims can be communicated across the European Union.

From this date, the new rules introduced by the Empowering Consumers for the Green Transition Directive (EU) 2024/825 apply. The Directive strengthens consumer protection against misleading environmental claims and introduces new rules covering generic green claims, sustainability labels, carbon-offsetting claims and statements about future environmental performance.

For real estate, this matters.

Sustainability has become an increasingly important part of how buildings are designed, financed, certified, sold and operated. Developers and owners routinely communicate about energy efficiency, renewable energy, carbon emissions, green certifications and future sustainability targets.

The question is increasingly no longer simply:

“Is this building sustainable / green?”

but:

“Can we substantiate what we are saying about this building?”

That shift — from green claims to the evidence supporting those claims — could become one of the important changes in sustainability communication for the real estate sector.

What has changed?

The ECGT Directive amends existing EU consumer-protection legislation, particularly the Unfair Commercial Practices Directive. Member States were required to transpose the Directive into national law by 27 March 2026, with the new rules applying from 27 September 2026.

In Hungary, the new requirements have been incorporated through amendments to the relevant consumer-protection legislation, and the Hungarian National Trade and Consumer Protection Authority (NKFH) has also published guidance on the new rules concerning green claims. The legislation is fundamentally focused on consumer protection, so in real estate its most direct relevance is to consumer-facing activities such as residential development and sales.

However, the underlying principle is relevant across the sector: environmental and sustainability claims need to be specific, credible and supported by appropriate evidence.

From “sustainable” to specific and verifiable

One of the most visible changes concerns generic environmental claims. Terms such as “green”, “eco-friendly”, “environmentally friendly”, “climate-friendly” and other similarly broad claims can be problematic when they create an impression of excellent environmental performance without sufficient substantiation. The Directive restricts such generic environmental claims where the party making the claim cannot demonstrate recognised excellent environmental performance relevant to the claim.

For real estate, this raises a simple question:

• What does “sustainable building” actually mean?

• Does it refer to energy consumption?

• Renewable energy?

• Embodied carbon?

• Water use? Biodiversity?

• Climate resilience?

• Indoor environmental quality?

• Or the overall environmental performance of the asset?
  

A statement such as:

“A sustainable residential development designed for a greener future.”

creates a broad impression of environmental performance without making clear what was actually measured or substantiated to support the claim. By contrast, communication based on a specific certification, energy performance, carbon metric or other measurable characteristic can be much clearer.

The important point is not that the word “sustainable” can never be used.

It is that the broader the environmental claim, the stronger and more relevant the evidence behind it needs to be.

One green feature does not make the whole building green

This is particularly important in property marketing. The Directive addresses situations where an environmental claim about an entire product or business is based only on a particular aspect of it.

In real estate, this distinction can be highly relevant.

A building may have photovoltaic panels, use recycled materials or have excellent operational energy performance. However, these individual characteristics do not necessarily demonstrate that the entire building is environmentally friendly or low-carbon.

Similarly, a certification provides evidence for the areas it actually assesses. A BREEAM, LEED or DGNB certification can provide valuable third-party assessed evidence of certain aspects of building performance, but it should not automatically be used as evidence for unrelated environmental claims.

For example, BREEAM assesses ten separate categories, and performance is rarely uniform across all of them. It also matters whether the certification applies to the design stage or the completed building, and, for commercial properties, whether it covers the shell and core or fully fitted-out state, common areas or individual tenant spaces. Similarly, when discussing energy performance, a distinction should be made between nominal technical specifications and actual consumption data from building use.

For developers and owners, the message is straightforward: the scope of the claim should not be broader than the scope of the evidence supporting it.

Carbon neutrality: reduction is not the same as offsetting

Climate-related claims deserve particular attention. The Directive specifically addresses claims that a product has a neutral, reduced or positive environmental impact in terms of greenhouse-gas emissions where such claims are based on offsetting.

For real estate, this reinforces an important distinction: reducing the actual emissions associated with a building and compensating for emissions elsewhere are not the same thing. This makes the underlying carbon data even more important, including operational carbon, embodied carbon and whole-life carbon, as well as the methodology used to calculate them.

A claim such as “carbon-neutral development” therefore requires considerably more scrutiny than simply asking whether the developer has purchased carbon credits. For projects with ambitious decarbonisation targets, the focus should increasingly be on measurable emissions reductions and a transparent pathway to delivery, rather than on the claim itself.

Future sustainability commitments also need a credible pathway

Perhaps one of the most interesting questions for developers and owners is not only what we claim today, but also what we promise for the future.

Real estate marketing increasingly includes statements such as:

“Net zero by 2030."

“Carbon-neutral operations.”

“Climate-positive development.”

Ambition itself is not the problem. The question is whether there is a credible implementation plan behind it. The new rules introduce requirements for future environmental performance claims, including clear, objective and verifiable commitments, measurable and time-bound targets, a realistic implementation plan and appropriate resources. The implementation of such commitments must also be regularly verified by an independent third-party expert.

This creates a much stronger connection between sustainability strategy → design → construction → operation → monitoring → communication.

A future sustainability target is therefore increasingly more than a marketing message: it needs to be supported by a credible pathway to delivery.

What should developers and owners do now?

For most organisations, the first step is not to stop communicating about sustainability altogether. Rather, it is to ask: what exactly are we claiming, and what evidence supports it?

1. Review your existing claims

Review project and corporate websites, brochures, sales materials, digital advertising, social media, property listings and materials used by sales partners. It is also important to review visual communication: environmental claims can be conveyed through images, symbols, labels and other visual elements, not only through written text.

2. Match every claim with evidence

For each significant environmental claim, ask:

• What exactly does the claim mean?

• What evidence supports it?

• Who produced or verified that evidence?

• How current is it?

• Does it apply to the entire building, or only to one part of it?

  
  

The aim is to establish a simple internal link between each communication claim and the relevant calculations, assessments, certifications or technical documentation supporting it.

3. Review future targets

If an organisation communicates a net-zero, carbon, energy or other environmental target, it should be supported by a realistic implementation plan and measurable milestones. A target alone does not necessarily constitute a credible strategy.

4. Establish an internal approval process

Environmental claims should not necessarily be left solely to the marketing team. A simple Marketing → Sustainability/Technical → Legal/Compliance process can help ensure that external communication remains consistent with the underlying technical evidence.

The bigger change: sustainability increasingly becomes evidence

The ECGT Directive does not mean that developers can no longer communicate about sustainability. On the contrary, developers and owners should continue to communicate their environmental performance. The change is in how they do so.

A building may have strong energy performance and ambitious carbon-reduction targets. But when it is presented to a buyer, tenant or other consumer, an increasingly important question is: Can the claim made in the marketing material be traced back to reliable evidence?

Assessments carried out by independent experts, such as BREEAM certification, EU Taxonomy compliance assessments or life-cycle assessments (LCA), can provide a strong foundation for credible communication. Nevertheless, precise wording remains essential. The fact that an assessment or study has been carried out can itself be communicated, but the emphasis should be on clearly and accurately presenting its results: making clear exactly which areas the assessment covered and what specific findings were reached.

Sustainability data therefore increasingly goes beyond certification or reporting. The evidence behind it becomes part of what a company can credibly say about its buildings. The future of green real estate marketing may therefore be less about finding better sustainability language — and more about having better, more reliable sustainability evidence.

Because a green claim is only as strong as the evidence behind it.

This article provides general information on the potential implications of EU Directive 2024/825 for the real estate sector and does not constitute legal advice. Specific obligations may vary depending on the nature of the communication, the target audience and the applicable national legislation.