FAQ

When replacing windows, one should take care to ensure that the walls are properly insulated. If the energy quality of the window is higher than that of the wall, humidity can condense on the walls, thus giving rise to the formation of mould. Condensation always appears in the coldest places.

To benefit from Klimabonus support, the performance of the wall insulation must be higher than that of the new window, or the windows must be replaced and controlled mechanical ventilation installed. When replacing windows, it may therefore also be necessary to insulate the façade. Contact your Klima-Agence adviser to determine the insulation performance of your building (free energy assessment).

In any case, after your windows have been replaced, proper daily ventilation must be ensured to maintain a healthy climate in your home.
 

When windows are not properly sealed, it leads to insufficient and unreliable ventilation and generally prevents correct ventilation in a dwelling. Adequate ventilation is achieved by opening windows or using a comfort ventilation system (CMV). On the other hand, windows that are not tightly sealed cause heat loss and draughts on cold days. These factors thus combine to create an unpleasant indoor climate and unnecessarily high heating costs.  

In you are retrofitting, it is advisable to have the new windows installed by a specialist, who will take care to remove any existing thermal bridges.

Mould growth is associated with elevated humidity levels and insufficient ventilation rather than with good insulation practice.

Indeed, the reverse is true: improved insulation quality prevents the formation of mould. This is found to be the case in many energy-efficient homes and buildings that have been retrofitted for energy efficiency. They are perfectly insulated, airtight and completely free of mould. If the external walls are not satisfactorily insulated, air moisture condenses in the cold areas, which favours the formation of mould. Effective thermal insulation of the façade tends to raise the surface temperature of the external wall and thus prevent moisture from accumulating.

It is likewise important to identify and eliminate all thermal bridges in the building (i.e. places where there are gaps in the insulation). Such bridges can be found, among other places, in recesses for radiators or on balconies. In addition, it is not advisable to place furniture in front of external walls, as this prevents the indoor air from circulating freely, meaning that the surfaces behind the furniture cool down.  
 

Benefit from financial support of up to 50% of the investment cost!

Under Article 4(h) of the Law of 31 May 1999, as amended, establishing a fund for the protection of the environmental, municipal administrations, municipal associations and public bodies under the supervision of the municipalities may receive aid covering up to 50% of the investment cost for projects for the rational use of energy and the promotion of new and renewable energy sources. This financial aid is accessible to all municipalities, regardless of their commitment to the climate pact.

Yes, the EPC training courses developed by the Ministry are open to everyone, including municipal employees. They can be booked on the Internet portal www.guichet.lu/experts-energie. In addition, in 2017 a workshop was organised on the subject of site inspections led jointly by the Ministry of the Economy, Klima-Agence and Syvicol. Klima-Agence is also prepared to strengthen its collaboration with the municipalities. If necessary, the municipality can contact the qualified adviser at Klima-Agence. Some additional EPC training courses are also available on the main Luxembourg training portals.

The possibility of developing integrated housing in single-family homes is dealt with in the Particular Development Plan (PAP). For PAGs that have been completely revised since 2011, the development of an integrated dwelling is permitted unless the municipality expressly rejects it in the PAP.

According to the Grand Ducal Regulation in force, an integrated dwelling is defined as additional accommodation forming part of a single-family house and belonging to the owner of the main dwelling. In theory, integrated dwellings allow for a soft densification of existing structures.

Within the framework of the building permit application procedure, it is not within the municipalities’ field of competence to monitor compliance with private property boundaries. The right of ownership is a fundamental right enshrined in the Constitution, therefore any encroachment of the façade insulation (considered as a fixed element of the building) on a neighbouring private property must be covered by the transfer of a real right over the plot of land in question, otherwise there is a risk of legal recourse within 30 years of the work being carried out (acquisitive prescription in real estate matters).

In the context of the building permit application procedure, it is necessary to respect the municipal planning regulations relating to setbacks from neighbouring private properties. The same provisions apply to constructions along the municipal public domain.