Policy status:Superseded
Policy Type:Regulatory Instruments>Codes and standards
Energy Efficiency Policy Targets:Buildings, Building Type, Residential, Multi-Sectoral Policy
Agency:Bruxelles Environnement (Brussels Capital Region Ministry of Environment)
Energy Efficiency Description:

Regarding EPB standards, the Calls for Exemplary Buildings have served as a test bench: they have provided confirmation that the passive standard is fully accessible and does not lead to major increased costs in residential buildings, schools or offices, in new construction and sometimes even in renovations.

Nowadays, Brussels already counts 1,511 passive units, which represents a total surface of 770,000m².
Following this experience, Brussels has decided that the passive standard (15 kWh/m²/year) will be implemented in January 2015 for any new construction. The Brussels-Capital Region will be the first European region to impose this degree of requirement.

The heating component of EPB is the one that will probably have the most impact. Reduction of CO2 emissions is estimated up to 166,000 tons in 2020. The air, climate and energy plan also foresees a strengthening of the EPB standards for simple renovations.


The main insulation standards for new buildings and retrofitting in the residential and tertiary sector currently being implemented in the three regions are as follows:


  • For new residential buildings (including hospitals, hotels, boarding schools, barracks, prisons) either the K55 standard (see definition below) or the Be 450 standard is enforced. In both cases, k max values for various building shells and a ventilation rate are enforced.
  • For new non-commercial tertiary buildings (offices, schools) K65 standard, k max values and a ventilation rate are enforced.
  • In the case of retrofitting of lodgement and non-commercial tertiary buildings with change of allotment, the K65 and K70 standards respectively are enforced, together with k max values and a ventilation rate. When retrofitting the above type of buildings with no change of allotment, only k max values for the retrofitted elements are enforced. For rooms with retrofitted windows, a ventilation rate is enforced.


  • For new residential buildings in the Flemish Region, the K55 standard is enforced as well as different k max values for various building shells.
  • For new buildings in the tertiary sector, i.e. hospitals, hotels, boarding schools, barracks and prisons, the Flemish Region enforces the K55 standard and k max values.
  • In retrofitting residential buildings, the Flemish Region implements k max values.
  • For buildings the use of which is changed the Flemish Region enforces k max values.



  • Since 1 January 2000, in the Region Brussels-Capital, the thermal insulation standards of buildings are similar to those in force in Wallonia.


The Belgian National Programme for Reducing CO2 Emissions calls for strengthening the thermal insulation of new buildings through the mandatory adoption of the K55 insulation standard in the residential and tertiary sector of the three regions. Before a building permit can be issued, the calculation of the K ratio is checked by the regional administration of town planning. There are no official inspections to check compliance with this regulation. Severe problems are associated with the enforcement of the building standards. According to a study carried out in Flanders, only 1/8 of the individual houses and 1/3 of apartment buildings constructed after the introduction of the standard meet the requirements. To address the problem of poor achievement, the number of inspections has been increased and additional measures are under consideration to ensure rigorous enforcement of the standards. As the Flemish Region has decided to introduce energy performance regulation in the near future, this problem will be tackled within this system from the start in order to avoid the errors of the past.



  • The K ratio concerns the total level of thermal insulation calculated on the basis of a technical standard established by the Belgian Institute for Standardisation (IBN). It takes into account mainly the insulation of the various shells but neither solar heat, nor occupant behaviour nor the efficiency of heating. The lower the K factor the better the total insulation of a dwelling.
  • The Be ratio concerns the calculation of the net needs for energy for heating, which means taking into account the free inputs of solar heat. The calculation of the Be ratio is published in the "Arrêtés" of the Walloon Government of 15 February 1996, "Moniteur belge" of 30 April 1996 and 9 May 1996.
  • A "k value" designates a heat loss coefficient of a wall system of a building. It allows the calculation of the specific heat loss of a wall while the K65 or K55 (note the capital K) is the heat loss value of a whole building. The current regulation in Belgium refers to a ?k maximum value? for every type of wall used in a building. Consequently, it is easier to use a "k value" for a wall in the case of a renovation project as the regulation would apply only to the walls that were renovated.
This record is superseded by:Flanders: Energy Performance of Buildings regulation

Last modified: Mon, 26 Sep 2016 11:50:23 CEST