According to statistics, 40% of energy consumption in Europe comes from buildings. This has led the European Commission to create Directives on Energy Efficiency that oblige us to improve the energy efficiency of buildings, introducing the concept of NZEB or Near Zero Energy Building. In this article, we explain what exactly an NZEB building is and its importance in sustainable development.
Energy consumption is something that occurs in a wide variety of circumstances and places, but it especially occurs in buildings, either family houses, residential buildings, commercial buildings or factories.
This is why there has been an important emphasis by the EU (European Union), as well as other organizations and countries to reduce the total amount of energy consumed by buildings. Starting with a reduction of the consumption to a considerable low level, until reaching almost zero amount of energy.
In order to reach this goal, models, plans and regulations must be established for both organizations and countries to achieve this goal in a given time frame. Thus, the concept of Nearly Zero-Energy Buildings (NZEB) has emerged.
What are Nearly Zero-Energy Buildings
Before giving a more formal definition of what Nearly Zero-Energy Buildings, or more commonly known as NZEBs are, it is important to clear up a confusion that often arises by just reading the term, and that is …
How could a building not consume energy?
A Nearly Zero-Energy Building isn’t literally an energy-free building. When we talk about nearly zero-energy buildings, we mean buildings that on the one hand consume nearly as much energy as they produce, and this energy, in turn, comes from renewable sources, produced locally or in the surroundings.
This means that NZE Buildings will continue to consume energy, but this energy will have a low impact over the environment, so they won’t consume energy from non-renewable sources such as oil or petroleum, natural gas, coal or uranium.
The official European Commission definition of NZEBs is a building that has 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.
Other terms commonly used instead of NZEB might be:
- Zero-Energy Building (ZE),
- Zero Net Energy (ZNE),
- Net-Zero Energy Build (also NZEB),
- Zero Carbon Building.
Most of them are used more or less interchangeably with Nearly Zero-Energy Buildings, however, some of these might be slightly harder to define.
And what criteria should European buildings follow in order to be nearly-zero energy from 2020 onwards?
In the case of every new building, they should now be built with sustainability in mind. While existing buildings should considerably reduce their energy consumption if they are going through a major renovation.
There are some aspects to be taken into account for buildings to become nearly zero-energy. First of all, it is not only about the sources of energy, but of the building’s energy needs, which makes it much more important for them to be built always taking sustainability and efficiency in mind.
4 Reasons in which NZE Buildings contribute to Sustainable Development
Sustainability can simply not be accomplished if it is not integrated into the life of people, as families, employees, occupants of buildings and members of society. Therefore, starting to build with sustainability criteria as a basis will be a must to achieve sustainability at city and country level.
In this sense, there are many ways in which NZEBs contribute to achieving sustainable development. Here are 4 of them:
1. Making buildings less energy-consuming by design
There are several ways in which we can reduce the amount of energy consumed. Many of these ways come from our own habits and behaviours as energy consumers, while many others come from our actual needs, as humans, and as employees.
As such, making sure of working along with architects and engineers to design building solutions that can better make use of the natural resources, such as sunlight, wind, the heat of the sun, location, among others, will help us reduce our energy consumption without affecting our comfort and needs.
2. Encouraging the adoption of renewable sources of energy
New buildings must be NZEBs by law, which means that the greatest part of the energy required for a building to work properly must use energy generated with renewable sources, mostly generated on-site or nearby.
This really helps changing or improving the perception towards renewable sources of energy, making it look not only as a good alternative but as a viable way of generating energy.
3. Using regulations as a way to ensure sustainable practices for building construction
Initiatives, such as the one from the EU, to transform any new building into NZEB by 2020, making it not only a possibility, but a necessity for building owners to use other techniques and materials that can ensure the reduction of energy consumption while providing occupants with what they need to live comfortably.
4. Creating a framework be followed to build highly efficient buildings
Overall, standardization is important because it helps to make sure that things that work will be predetermined. This way, initiatives for NZEBs can create this framework or guidance with the tools, materials and techniques available for the construction of sustainable and smart buildings.
There are already certifications and standards that help achieve the goals of Near Zero Consumption Buildings or Sustainable Buildings. Among them, the most well-known are:
If you want to know more about them, we leave you this blog-post where you will find a definition of each one.
6 Examples of Sustainable Buildings
When having a goal such as making every new building a nearly zero-energy building within a relatively short amount of time, it is very important to count with examples of successful implementations or pilots for this type of construction.
Seeing what is currently possible, and what has been achieved already, works as a source of inspiration, as well as a motivation boost. NZEBs are not only a dream but a demonstrated reality.
Let’s discover some successful examples of international implementations:
Located at Graz, the second largest city of Austria, this is a complex built to meet the standards of passive house, with the main goal of having common spaces in central locations, as well as several open areas.
It was built with insulated bricks, with triple glazing on the windows to ensure the best air circulation, and the house is heated by district heating.
Technical University – Sofia, University Research Center
In Sofia, the capital of Bulgaria, the infrastructure of the university was improved, which led to an energy performance improvement of around 45% compared to current norms. Brick and concrete with thermal insulation and windows with double glazing were used.
West of Copenhagen, the city of Roskilde in Denmark was the place where the renovation and transformation of a building into a low-level energy consuming building of apartments.
For this, the thermal envelope was improved by using walls with up to 480 mm of insulation, 400 mm for the roof, with three-layer low-energy glazing for windows. The building is also connected to a district heating network and features mechanical ventilation.
Järvenpää Zero Energy House
With the goal of being the first zero-energy house in Finland, this house in Järvenpää has concrete walls with 300 mm insulation walls. It counts with a water-based heating system, low-energy lighting, and a mechanical ventilation system.
With the goal of producing a nearly zero-energy building in France, this single-family house located at the French commune of Niort has brick walls and a roof insulated with mineral wool inside. For heating, a gas-condensing boiler delivered by a floor-heating system is used.
University of London, Stratford New Library
The University of London, in the city of London, England, in the UK, aimed to provide modern library facilities for the students of this university. It uses well-insulated concrete slab for the roof, and two types of walls, insulated bricks, as well as insulated glazed curtain wall. It is heated by Low-Temperature Hot Water.
Even if a few years might be needed before every new building reaches a zero-energy state, and most existing buildings get the necessary renovations to become nearly zero-energy buildings; it is clear that this is one fundamental aspect towards building the cities of the future, and achieving sustainability.
And now that you have all this information, and you have a clear idea about the Nearly Zero Energy Building (NZEB) concept, go a step further and watch our Webinar on “the NZE Building, Microgrids and Photovoltaic trends”: