In Europe, the Energy Performance of Buildings Directive was recast in 2010, in large part to set more ambitious goals for the energy performance of buildings. As of December 31, 2020, all new – residential and non-residential – buildings will have to be “nearly zero energy.”
Nearly zero energy buildings can completely transform the buildings sector over upcoming decades and will make a major contribution to Europe reducing its GHG emissions. But it will only happen with good planning and rigorous implementation. Here is the state of play:
Definition
The Directive does not clearly define what a “nearly zero energy building” is. Article 2(1a) gives a purely qualitative definition:
A “nearly zero energy building” is a building that has a very high energy performance. The nearly zero or very low amount of energy required should be covered to a very significant extent by energy from renewable sources, including energy from renewable sources produced on-site or nearby.
Deadlines
There are different deadlines for public buildings and for all buildings:
- after 31 December 2018, new buildings occupied and owned by public authorities are to be nearly zero-energy buildings.
- by 31 December 2020, all new buildings are nearly zero-energy buildings.
The national plans for implementing Nearly Zero Energy Buildings (NZEB or sometimes nZEB) are due to be sent to the Commission in early 2012. Informally, the date is June 2012 although that is not in the Directive. What is in the Directive is that the Commission is required to evaluate and comment on the strategies by the end of 2012.
Progress to date
An eceee report, Steering through the maze #2: Your guide to zero energy buildings, summarises the current state of play in member states, showing that many are well on the way:
Selected National Targets for New Buildings
| Country | Target |
| Denmark | 75% by 2020 (c.f. base year 2006) |
| Finland | Passive house standards by 2015 |
| France | By 2020 new buildings are energy-positive |
| Germany | By 2020 buildings should be operating without fossil fuel |
| Hungary | Zero emissions by 2020 |
| Ireland | Net zero energy buildings by 2013 |
| Netherlands | Energy-neutral by 2020 (proposed) |
| Norway | Passive house standards by 2017 |
| UK (England &Wales) | Zero carbon as of 2016 |
Defining the Definition Problem
In November 2011, the Buildings Performance Institute Europe published an important study, Principles for nearly Zero-Energy Buildings, to help MS in the context of the lack of a specific definition. “There is an urgent need to establish common principles and methods to be taken into account by EU Member States for elaborating effective, practical and well thought-out nZEB definitions,” it says.
The study raises important questions concerning the practicalities of a NZEB definition:
- how to keep the nZEB definition sufficiently flexible so as to build upon existing low-energy standards and enable energy-positive buildings?
- how to properly define and set the share of renewable energy?
- how to determine the optimal balance between energy efficiency and renewable energy?
- how to forge the nZEB definition as a ‘silver bullet’ for reaching the same levels of energy and GHG reduction?
- how to link the nZEB definition to cost-optimality principles in order to have convergence and continuity?
The study states that the characteristics of a definition should be:
- To be clear in its aims and terms, to avoid misunderstandings and implementation failures.
- To be technically and financially feasible.
- To be sufficiently flexible and adaptable to local climate conditions, building traditions etc., without compromising the overall aim.
- To build on the existing low-energy standards and practices.
- To allow and even foster open competition between different technologies.
- To be ambitious in terms of environmental impact and to be elaborated as an open concept, able to
- keep pace with the technology development.
- To be elaborated based on a wide agreement of the main stakeholders (politicians, designers, industry, investors, users etc.).
- To be inspiring and to stimulate the appetite for faster adoption.
The BPIE Principles
First nZEB Principle: Energy demand
There should be a clearly defined boundary in the energy flow related to the operation of the building that defines the energy quality of the energy demand with clear guidance on how to assess corresponding values.
Second nZEB Principle:Renewable energy share
There should be a clearly defined boundary in the energy flow related to the operation of the building where the share of renewable energy is calculated or measured with clear guidance on how to assess this share.
Third nZEB Principle: Primary energy and CO2 emissions
There should be a clearly defined boundary in the energy flow related to the operation of the building where the overarching primary energy demand and CO2 emissions are calculated with clear guidance on how to assess these values.
The BPIE study covers many aspects, but constantly refers back to the question of cost. Here is what the BPIE study says:
Financial impacts at EU level
The turnover in the building industry in the EU for non-residential and residential buildings in 2009 was about € 1 trillion, about half of that amount (€ 470 billion) is due to new buildings. Based on several market studies, actual investments in new buildings for heat pumps, pellet heating systems, ventilation systems with heat recovery, triple glazed windows and insulation materials at EU level are estimated to reach about EUR 23 billion. To implement nZEB requirements for every new building, the investments are estimated to reach about € 62 billion per year. The difference of € 39 billion would represent an overall increase of about 9% [EID’s emphasis], being a considerable growth that seems achievable when taking place over the years until 2020 (approx. 1% increase per year).
Reader Exchange
EID got an urgent email a couple of weeks ago reporting that in his country work was underway on a definition and strategy, as required, but there was a very disappointing lack of ambition. This is in a country that is normally seen as proactive and forward thinking. Please let EiD know what is going on in your country. We will share progress and setbacks with the EiD readership.
And please note that World Sustainable Energy Days will be holding a Nearly Zero Energy Buildings Conference on March 1 and 2, 2012, in Wels, Austria. It may be well worth attending.
Energy in Demand - Sustainable Energy - Rod Janssen 