GWP buildings 2026: what changes for developers and contractors

Key data

Real estate developers, contractors and architects operating in Spain and the European Union have a new obligation from 1 January 2026: to calculate the climate impact of their buildings using a common European methodology. The Delegated Regulation (EU) 2026/52, approved on 16 December 2025 and published on 4 May 2026, amends Annex III of the EPBD Directive 2024/1275 and establishes the framework for calculating global warming potential (GWP) throughout the lifecycle of buildings.

The change is significant: until now, Member States could apply their own methodologies. From 2026 onwards, there is a harmonised framework that requires measuring both carbon embedded in materials and the building's operational emissions throughout its entire lifespan.

What does this regulation establish?

Delegated Regulation (EU) 2026/52 updates Annex III of the Energy Performance of Buildings Directive (EPBD 2024/1275) with the following key elements:

The key to the change is harmonisation: any national methodology is no longer acceptable. All building projects in the EU must follow the same framework so that data is comparable between countries and serves to measure progress towards 2050 climate objectives.

Economic and operational impact

The impact is not just technical. Adapting to this new methodology has direct consequences for the operations and costs of any company in the sector:

• Investment in calculation tools: Companies will need to update or acquire specialised software capable of calculating GWP according to the new European methodology. Current tools may not be compatible with the new Annex III framework.
• Training of technical staff: The regulation expressly provides that specialised training may be necessary for architects, engineers and site technicians who must apply the new calculation in their projects.
• Review of design processes: GWP calculation must be integrated into the design and material selection phases, which may extend project timelines or require changes to usual processes.
• Impact on material selection: By having to calculate the carbon embedded in construction materials, the choice of suppliers and materials may be conditioned by their declared carbon footprint.
• Public administrations: Public bodies that promote building must also adapt their specifications and tender criteria to this new methodology.

Who does it affect?

The regulation has a direct impact on all agents in the building sector:

• Real estate developers: Must require and verify that the projects they promote incorporate GWP calculation according to the new methodology.
• Construction companies: Affected in the selection of materials and in the technical documentation of works.
• Architects and architecture firms: Required to integrate lifecycle calculation into their projects from the design phase.
• Public administrations in building: Must adapt their tender, supervision and certification processes for public works.
• Manufacturers and distributors of construction materials: Although not the direct recipient, their clients will require them to provide embedded carbon data (Environmental Product Declarations, EPD) to be able to perform the calculations.

Practical example

A developer that begins in 2026 the development of a residential building with 40 apartments must, from the project phase, calculate the total GWP of the building throughout its lifecycle. This involves:

1. Requesting from each material supplier (concrete, steel, insulation, carpentry) their Environmental Product Declarations (EPD) with embedded carbon data.
2. Entering that data into a calculation tool compatible with the methodology of Regulation (EU) 2026/52 to obtain the building's total GWP.
3. Adding the estimated operational emissions during the building's useful life (heating, cooling, domestic hot water).
4. Documenting the result as part of the project's technical file, for the purpose of obtaining licenses and certifications.

If the developer does not have updated tools or its technicians are not familiar with the new methodology, the project may suffer delays in the administrative processing phase or fail to meet the energy certification requirements required by the EPBD.

What should companies do now?

1. Review whether current or design-phase projects are affected: The entry into force is 1 January 2026, so any project processed from that date must comply with the new methodology.
2. Audit available calculation tools: Verify whether the energy and lifecycle calculation software your team uses is compatible with the new Annex III framework of EPBD 2024/1275. If not, initiate the update or replacement process.
3. Plan training for technical staff: Identify which architects, engineers and technicians need training in the new GWP methodology and seek specialised training programmes.
4. Update material selection processes: Incorporate as a selection criterion the availability of Environmental Product Declarations (EPD) from suppliers, as they are necessary for calculating embedded carbon.
5. Adapt contract models and specifications: If you are a public administration or a developer working with contractors and architecture firms, update contracts to require compliance with the new GWP calculation methodology.
6. Consult with a building regulation specialist: Given that the standard amends Annex III of the EPBD and its practical application may vary depending on the type of project, it is advisable to have specialised technical-legal advice.