The Recast EPBD Article 9 requires Member States to ensure that all new buildings are nearly zero-energy buildings (NZEBs) by 31 December 2020, and new buildings occupied and owned by public authorities are NZEBs after 31 December 2018. Furthermore, Member States are required to draw up national plans that include the countries' detailed application in practice. The deadlines are moving closer and many Member States have legally established a national definition of NZEB. But which national definitions are ready and what do they look like?
Basic definition of the Recast EPBD
Article 2.2 defines the NZEB as “a building that has a very high energy performance, as determined in accordance with Annex I. The nearly zero or very low amount of energy required should be covered to a very significant extent from renewable sources, including energy from renewable sources produced on-site or nearby.”
Timing for the national definition of NZEB
National NZEB plans shall contain the national application of this general definition. They shall be sent to the European Commission every three years, contributing to a Commission report on the Member States’ progress toward increasing the number of NZEBs. Three years have now passed since the adoption of the Recast EPBD, and most national NZEB plans have been sent and assessed in a progress report. Some of these plans, however, only include the wording of Article 2.2 of the Recast EPBD as a national definition. Why is that?
The defined NZEB requirements will become national Energy Performance (EP) requirements for all new buildings in 2021, and for new public buildings in 2019. Many countries are setting EP requirements under the precondition that these requirements are cost-efficient for the building owner over a certain building lifetime. The EPBD follows this approach, by calculating cost-optimal levels of minimum energy performance requirements (Recast EPBD Article 5), in order to assess the national requirements.
However, many parameters including energy prices, costs of technologies, primary energy factors for electricity and district heating and cooling cannot be reliably predicted for 2019/2021, and therefore detailed NZEB definitions fixed early on could be either too tight or too loose. This makes some countries wait until developments are clearer before establishing a detailed NZEB definition. Other countries have tried to get around this challenge by including the possibility of adapting the current NZEB definitions later on. The advantage of this approach is that the relevant industry and planners already have an insight into what requirements are expected in the coming years, and can thus make appropriate decisions for future technologies and designs. Nevertheless, even for countries without an established NZEB definition, the road towards more efficient buildings and increased use of renewable energy is clear.
The work of the Concerted Action EPBD
The Concerted Action on the Energy Performance of Buildings Directive (CA EPBD) was launched by the European Commission to support the implementation of the Directive through promoting dialogue and the exchange of best practices. It is an active forum of national authorities from the 28 EU Member States plus Norway, with a focus on finding common and effective approaches. During the third phase of CA EPBD (2011-2015), one of the seven core themes focussed on NZEBs. Throughout the 4-year working period, much effort was spent analysing the initial approaches to establishing national NZEB definitions, exchanging experiences with high performance buildings and following up on the increasing number of legally established national NZEB definitions. At the end of this project phase, a report was published which includes the status of national NZEB definitions as of April 2015. The information included is based on the national NZEB plans, the work in CA EPBD and the review of the CA EPBD delegates.
The report shows that at that time about 60 percent of EU Member States had established a detailed and legally supported NZEB definition. This could take the form of a national regulation such as an energy decree or an act, a law, or simply that the national NZEB plan was sent to the Commission. However, the report also shows that the national definitions tend to differ between countries in all major areas:
- requirements for “very high performance” and limits for “nearly zero or very low amount of energy required”;
- requirements for “very significant extent of renewable energy”;
- primary energy indicator.
For example, the primary energy indicator, explicitly requested in kWh/m²year, is not part of all NZEB definitions. Some countries have set a CO2 indicator, use final energy as a main requirement or use primary energy in relation to a reference level, which leads to a different unit than kWh/m²year. There are, however, developments underway that might lead to using primary energy as an additional or future indicator.
The national NZEB definitions have been developed in many countries on the basis of studies including cost-optimal analyses and have been subject to public or industry consultations. A few countries like Denmark, Ireland, Latvia, Lithuania and Bulgaria use the NZEB as a voluntary building class, already included in the current energy performance certificate.
While several countries’ NZEB requirements include a percentage of renewable energy or a minimum amount of renewable energy in kWh/m²year, others include only indirect requirements for renewable energy. They state that due to the low maximum value of primary energy use allowed for NZEBs, the use of energy generated from renewable energy sources is implied.
Note: The author, Heike Erhorn-Kluttig from the Fraunhofer Institute for Building Physics, is part of the NZEB core theme lead in the Concerted Action EPBD.