Assessment of the feasibility and potential impact of adding additional ecolabel criteria for global warming impacts of buildings and building materials

Weidema B P, Trolle T S (2020)

Publication info

Executive summary

What are the options for Nordic Ecolabelling to support the reduction of global warming from buildings by adding more requirements for specific building materials or building parts, e.g. by requiring calculations of the global warming impact for either a part for the entire life cycle of the buildings? We investigate this question by reviewing the current landscape of life-cycle based standards, methods and tools available for designers and producers of buildings and building materials. We identify a number of ambiguities in the standards that cause inconsistencies in their interpretation and practical implementation, resulting in a limited comparability of results from different databases and tools.

We conclude that the current consistency and comparability of life-cycle based calculations for construction products are insufficient to be the basis for the Nordic Ecolabelling programme to require such calculations as part of their criteria. In spite of this, we identify three areas where ecolabelling criteria would currently be verifiable:
• Requirements on specific construction products with identical functionality, where greenhouse gas emission reductions are clearly verifiable, e.g. when obtained through light-weighting.
• Requirements aiming at increasing recycling, such as design for disassembly and minimum recycling targets specified by material type.
• Requirements to reduce overall material demand over the forecasted service life of the building under well-specified, realistic use scenarios.

It is obviously not the role of the ecolabelling programmes to rectify the current consistency and comparability problems of life-cycle based calculations or the ambiguities in the standards. Nevertheless, to incentivise radical building design changes, it is imperative to seek cooperation with other stakeholders that have similar interests in obtaining consistent and comparable results from life-cycle based calculations, an issue that is not limited to building materials. We recommend a cooperation of stakeholders with the aim of establishing a common open database that:
• Has globally complete system boundaries,
• Links unit processes according to verifiable cause-effect relationships,
• Enforces a strict completeness requirement on the included unit processes, using mass and monetary balancing,
• Includes future scenarios based on realistic and transparent procedures,
• Requires activities, and thus flows, to be clearly specified in time, and
• Requires all flows to be provided with uncertainty.

All of these aims can be seen as supported by the current standards. Once a database with the above specifications has been established, we recommend that Nordic Ecolabelling requires LCA calculations to be performed with data from this database, unless the user can provide improved data.

We recommend that such calculations be required at the whole building level, in a phased approach comparable to that currently applied in the Norwegian FutureBuilt programme. Here, a total of four calculations are required:
• A baseline calculation, following detailed, unambiguous rules,
• The targeted building, where a reduction criterion relative to the baseline building must be met,
• For the completed building, as built, for the building after 2 years of operation, with data for realised consumption and transport patterns of users.

An additional calculation is also recommended for the choice of demolition of any pre-existing building and building new versus renovation of the pre-existing building.

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