Burenberg duurzaam project Leuven

If you had a Nearly Zero Energy Building (NZEB) constructed five years ago, you were ahead of the curve, but nowadays NZEBs are the norm. Since 2021, it has been mandatory in Flanders for all new builds to consume nearly zero energy. This is a positive trend, because NZEBs require very little energy for heating, ventilation, cooling and hot water. And the energy they consume comes from green sources as much as possible. This is not just good for the environment, but also for your monthly energy bill.

Brikkerij 4 privépark

The NZEB standard

In 2006, a European energy performance standard was laid down setting the E level for new builds at 30 or below from 2021 onwards. The E level is a score that indicates how energy-efficient a building is in standard conditions. The lower the E level is, the better. In the past, ensuring that we met the standard was a challenge, but nowadays this is perfectly possible thanks to new (insulation) techniques, energy generation principles and smart design.

In addition to the E level, NZEBs have to comply with the following requirements:

  • An E level of 30 or below (this expresses the energy efficiency of a building)
  • An S level of 31 or below (this expresses the energy efficiency of the building envelope)
  • A net energy demand for heating of maximum 70 kWh/m2
  • A few statutory rules concerning the risk of overheating


The lower energy bill and reduced dependence on fossil fuels are not the only interesting aspects. The subsidies you are entitled to are also worthwhile. If the E level of your home is considerably lower than the standard, you will automatically get a property tax reduction. Under certain conditions, it is even possible to get a grant from grid operator Fluvius.

What does ION do?

Of course, we do what it takes to innovate and not be overtaken by developments. For instance, we have built housing units with an E level of 0 by investing in (communal) solar panels and geothermal heat pumps. This means that these homes generate as much energy as they consume, which makes them energy neutral. Note: this does not mean that the energy cost will be zero. What is does mean is that this cost will be considerably lower, because the energy you consume is in balance with the energy you generate.

What is a geothermal heat pump?


A geothermal or ground-source heat pump ensures that a heat-carrying fluid circulates through an underground tube system. As the natural heat of the soil raises the temperature of the fluid in the tubes, we obtain added energy. The district heating network in Suikerpark Veurne, where homes are heated with waste heat from a PepsiCo factory, is another contemporary example of a sustainable solution.

At ION, we continue to look ahead and innovate. We are fully committed to a sustainable world!

Take a look at the residential projects that have been planned!


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