FAQ

The energy performance certificate (EPC) or energy passport is the quality label that defines the energy performance of a residential building. The certificate provides information on the energy efficiency of residential buildings and thus allows comparisons to be made with other residential buildings. Thus, even without technical knowledge, the consumer can assess the energy quality of a residential building.

The obligated parties have a certain degree of freedom in their choice of energy efficiency measures. In order to guide their services, they can achieve energy savings either through standardised measures or specific measures. The standardised measures set out different example cases and set flat-rate energy saving values for the following families of measures:

•  Thermal envelope of buildings (walls, windows, roofs, slabs)
• Heat production
• Mechanical ventilation
• Household appliances
• Office equipment
• Lighting
• Transversal industrial techniques (motors, pumps, ventilation, compressed air, boilers, refrigeration)
• Management energy
• Transport (replacement of cars).

Energy efficiency measures not included in the catalogue of measures are to be considered as specific measures, which cannot be accounted for by the obligated parties in case of certain calculation principles and if no standardised measures are applicable.

In order to claim for energy efficiency measures, the obligated parties must demonstrate that they have played an incentive role in carrying out the measures. This means that they must support the consumer who carries out the measure in question with a direct contribution. For example, this incentive might take the form of advice, technical support or a financial contribution. These incentives must be provided before the consumer orders the measure in question.

The obligated parties are electricity and natural gas suppliers active in Luxembourg.
Please check the website of the Luxembourg Regulatory Institute for a complete list of these suppliers.

To initiate energy efficiency measures, the obligated parties are free to act themselves or to use third party implementers.

In principle, the energy savings that can be accounted for by the obligated parties can be in any energy carrier, including fuels, oil, natural gas and electricity.

In principle, all energy consumers are affected, whether households, businesses or the public sector.

The implementation of this obligation mechanism was born out of the desire to achieve the objectives set out in the national energy policy on energy efficiency more effectively.

This measure allows the obligated parties to seize the opportunity to expand their business models and offer energy services to consumers. The experiences of other EU Member States that have already implemented such a mechanism have shown that this approach, based on sound regulation, makes possible the subsequent deployment of energy efficiency measures.

In principle, a wall does not breathe. Air renewal and moisture removal are only achieved by ventilation (via windows or a mechanical ventilation system). The effect of 'breathing' as mentioned above refers to the transfer of moisture by the diffusion of water vapour. In practice, this is minimal and does not play any role in the removal of moisture. On the other hand, it is important for interior plaster to be able to absorb moisture from the air and release it back into the interior after ventilation. The moisture regulation effect therefore only operates within the first few centimetres (on the interior side) of a wall. For example, clay plaster on internal walls provides excellent moisture regulation.

It is often façade insulation systems that are implicated and pilloried for this. It is true that on insulated walls the outer render layer has a lower temperature and slows down the drying of rainwater and condensed water. However, in order to determine the origin of the spread of micro-organisms, various factors have to be taken into consideration: weathering, orientation, proximity of trees or bushes and the lack of protection provided by protruding building elements (roof overhang, window sill, projection, eaves, etc.).

For new builds, weather protection should ideally be provided from the outset. Similarly, by opting for a thicker finishing coat, higher surface temperatures can be obtained.