The strategies adopted by Nordic countries in the implementation of limit values differ in several respects. Regarding the coverage of carbon limit values, particular building types or sizes might be excluded, and different building types may have different limit values. The pace of the respective decarbonisation strategies (initial limit value and trajectory for its future revision) also differs. Denmark at first introduced a single limit value for all buildings exceeding 1,000 m2, with an easily achievable initial level, followed by a planned biennial revision. Based on the experiences gained from this initial limit value introduction, updated limit values, differentiated by building type and covering 85% of new construction in terms of building types and sizes, will be valid from July 2025. Sweden initially introduced a mandatory declaration without a limit value, which will be followed from July 2025 with ambitious limit values differentiated by building type, updated every five years.
Multiple differences are also apparent in the life cycle assessment (LCA) methods used in each country. As a result, comparing assessments becomes more challenging, but there are numerous opportunities for harmonisation. The most important methodological differences relate to:
Covered assessment scope: the required scope for a declaration and a limit value may differ as a declaration can drive learning and include a more extended scope, while a strict limit value requires higher assessment quality and precision to ensure robust compliance with the regulation. Regarding building parts, the inclusion or exclusion of deep foundations, soil stabilisation, external works, internal finishes, fixed furniture and building services causes considerable variability. According to the revised EPBD, Level(s), which is currently undergoing some updates, will set the minimum requirements for the building model scope at least for the mandatory climate declarations from 2028, which might be further specified in a Delegated Act. It is unclear whether the binding carbon limits should be subject to the same minimum scope as declarations when they are introduced on an EU level in 2030. The definition and inclusion or exclusion or elements in the limit value scope may have an impact on the localisation of a new build. Thus, we find that particularly deep foundations and external works are aspects that warrant consideration with more detailed clauses in further updates of Level(s). In relation to the covered life cycle modules, most current declarations and limit values exclude some modules of the life cycle. A striking example is the Swedish declaration, which explicitly focuses on upfront embodied carbon (module A) in its first implementation. However, some countries have already planned to expand this scope, which also aligns with EPBD’s requirement for a full life cycle scope disclosure from 2028.
Building floor area definition: national floor area definitions differ in whether they include basements, balconies, circulation areas and external wall thickness. The EPBD and Level(s) framework use the notion of “useful floor area”, not yet used in any Nordic national framework.
Treatment of exported energy: The allocation of impacts and benefits from exported onsite energy production is expected to have two options according to the EN 15978 revision. The Nordics and Estonia can achieve harmonisation by choosing a common option.
Biogenic carbon reporting: Among the countries with a carbon declaration already in place, Sweden and Norway explicitly exclude biogenic emissions from the scope of the declaration, as they do not include C modules (end-of-life stage), while Denmark includes them (showing a negative value in module A and a corresponding positive value in module C). This is primarily a matter of transparency, as the total life cycle impact is similar (in the absence of discounting factors). However, it is unclear whether the Nordic countries will decide to introduce biogenic carbon reporting as separate information in future revisions of declaration methods, and whether this will be an aspect also addressed in the Delegated Act expected by mid of 2025. The revised EPBD text state that information on carbon removals associated with the temporary storage of carbon in or on buildings along the life cycle global warming potential (GWP) indicator may be declared in the energy efficiency certificate (see EPBD, Annex V).
Which future scenario(s) are considered for modules B and C: it is common to include a decarbonisation scenario for the energy mix in module B6, but assumptions taken as part of this scenario can affect the assessment results considerably. No Nordic national method considers future scenarios for the embodied part of B and C stages, but these have been considered in other initiatives. Relatedly, discounting factors can also be used to give a higher weight to emissions the earlier they happen, which considerably favours temporary biogenic carbon storage. Although this approach is not used in the Nordics, the French national method implements it.
Definition of conservative standard values for building systems and generic values for products: considerable differences are found between the various Nordic databases of generic product emission factors. Some of these differences can reflect actual differences in the supply chains of products used in each national market, but differences can partly be explained by how conservative generic factors are defined. For instance, Estonia and Finland use the average of a product sample plus 20%, Norway and Sweden use a 25% factor, and Denmark uses the upper quartile of an EPD sample instead.
As for bottom-up building stock monitoring, the level of national limit values for buildings’ GWP can be derived from LCA cases using an archetype approach or a sampling approach. It is particularly important to use a building sample that is representative of new construction to be able to draw reliable conclusions. Limit values can be defined as the X% percentile of the sample results, thus defining a certain share of current projects which would have to alter their design or material choice to meet the target. This is the rationale followed in Denmark, where the initial limit value was set as the 90th percentile of a building sample (i.e., 1/10 buildings must perform better), and the updated value for 2025 corresponds to the 15th percentile of an updated representative sample (i.e. 17/20 buildings must perform better). Considering that the recently established limits for 2025 are already within the range of current good practices, the latest agreement suggests that the limits for 2027 and 2029 will be lowered by approximately 10% compared to the previous limits, until more data is available regarding the impact of regulation.
The introduction and tightening of carbon limit values may have various complex economic, social and environmental consequences that require careful consideration. One direct consequence is the change in design and material choices in building projects. As limit values become stricter, optimised versions of conventional products will need to be developed, such as using alternative binders in concrete and changing production processes. However, if limit values are set too low to be achieved with optimised products, designers will have to alter the building designs. This can entail avoiding balconies or making changes to interior layouts. Importantly, there may be a shift towards using alternative materials, particularly bio-based materials, and an increase in timber construction if mineral materials cannot be sufficiently decarbonised. This has potential consequences for architectural identity, as well as for environmental indicators other than climate change, although data quality was found to be too low to draw robust conclusions for other impact categories. Importantly, to address the increased demand for wood products complementary policies and incentives are needed to mitigate potential adverse effects on land use, biodiversity and forest carbon storage. Efficient use of wood in construction would entail a cascading use of wood products, prioritising the use of timber in high-value engineered products and ensuring the possibility of future reuse and recycling by using reversible joints and non-chemical connections. Incineration should only be considered as a last resort. This should be combined with sufficiency measures on the demand side in order to avoid unnecessary material use. Finally, such changes also carry socio-economic implications, including potential cost increases in development projects and fluctuations in economic activity for construction material suppliers. For example, in Denmark, it is estimated that the construction cost for reducing the climate impacts of typical buildings to comply with the tighter limit values to be in effect in 2025 will lead to an increase of DKK 220/m2 (i.e. EUR 30/m2). The socio-economic consequences of such policy proposals must therefore be assessed on a case-by-case basis, and complementary measures to secure stakeholder support might play an important role when developing decarbonisation policies.