Key Takeaway
An energy performance certificate does more than indicate a property’s current consumption. It also helps assess its improvement potential and anticipate certain future investments.
Why is the energy performance certificate important?
In Luxembourg, a valid energy performance certificate is required when a property is sold. Beyond this requirement, it is a valuable source of information for owners, buyers and investors.
The document can notably help assess:
- The building’s energy performance.
- The quality of its insulation.
- The technical systems installed.
- Theoretical heating consumption.
- Its potential for energy improvement.
- Future investments that may need to be considered.
For a buyer, the certificate can help anticipate future costs more accurately. For a seller, it is often an important part of discussions with prospective buyers.
How is an energy performance certificate organised?
The document contains several pages, each addressing a different question.
| Page | Main content | Why it matters |
|---|---|---|
| Page 1 | General information | Check the building’s reference data |
| Page 2 | The three energy ratings | Understand the property’s performance |
| Page 3 | Technical systems | Assess the heating and hot-water systems |
| Page 4 | Actual consumption | Review observed energy use |
| Page 5 | Recommended improvements | Assess the building’s potential |
Page 1: general information about the building
The first page is often reviewed quickly, even though it contains several important pieces of information.
It notably includes:
- The building’s year of construction.
- Its energy reference area.
- The certificate’s issue date.
- Its expiry date.
Why is this information important?
The year of construction often helps place the building in its technical context. Insulation and energy-efficiency requirements were clearly not the same in the 1970s, the 1990s and today.
The energy reference area also deserves particular attention. It may differ from the living area stated in a property listing. A quick comparison can sometimes help explain certain figures shown in the certificate.
Finally, always check the certificate date. Like other technical documents, the energy performance certificate has a limited validity period.
Key Takeaway
Before reviewing the energy ratings, check that the building’s general information is consistent with the information provided in the sales file.
Page 2: understanding the three energy ratings
This is probably the best-known page of the energy performance certificate. It presents the three ratings that summarise different aspects of the building’s performance.
Many people focus only on these ratings. However, each one measures a different aspect of the property.
The first rating: energy performance
This rating provides an indication of the building’s energy consumption. It depends notably on its insulation and the system used for heating.
In general, technologies such as heat pumps or pellet boilers often achieve better results than systems using fossil fuels.
The second rating: heating requirements
This rating is directly linked to the quality of the building envelope.
It depends notably on:
- Wall insulation.
- Roof insulation.
- The type of glazing.
- The building’s airtightness.
- The ventilation system.
A well-insulated building retains more heat and therefore requires less energy to remain warm.
The third rating: environmental impact
The third rating indicates the CO₂ emissions associated with the building’s calculated energy consumption.
It depends notably on the energy source used for heating and domestic hot-water production. A building heated with gas or oil may therefore receive a less favourable rating for this indicator than a building using an energy source with a lower calculated environmental impact.
This third rating should not be confused with the quality of the insulation. It provides complementary information about the environmental impact of the building’s energy system.
How should the three ratings be interpreted?
- The first rating reflects the building’s calculated overall energy performance.
- The second rating indicates heating requirements and therefore, notably, the thermal quality of the building envelope.
- The third rating indicates the CO₂ emissions associated with calculated energy consumption.
What should a buyer really look at?
The ratings provide a useful summary, but they should not be interpreted in isolation. Two properties with the same energy rating can have very different technical conditions, running costs and renovation potential.
A property rated E or F is therefore not automatically a poor purchase. Its appeal also depends on:
- The asking price in relation to its actual condition.
- The age and condition of the technical systems.
- Work already completed.
- Improvements that remain technically possible.
- The estimated cost of the work.
- The rating the building could reasonably achieve after renovation.
Conversely, a good energy rating does not remove the need to assess the property’s overall condition, installations, observed consumption and any work that may be required.
Key Takeaway
The current rating is a starting point. To assess a property properly, buyers should also examine the reasons behind that rating, the work required and the level of performance the building could realistically achieve.
Page 3: understanding the technical systems
The third page describes the systems used to heat the building and produce domestic hot water. It also contains information relating to their theoretical consumption.
This page helps explain how the property produces and distributes the energy required for its operation.
Information to review
- The main energy source.
- The type of heat generator.
- The domestic hot-water production system.
- The possible presence of several systems.
- The theoretical consumption associated with the equipment.
Why is this page important when buying?
A well-insulated building may still require significant investment if its heating system is old or approaching the end of its service life. Conversely, a recent and efficient system will not always offset major weaknesses in the thermal envelope.
This page should therefore be read alongside the information available in the sales file:
- The installation date of the boiler or heat pump.
- Available maintenance invoices.
- Repairs already completed.
- Energy-renovation work completed after the certificate was issued.
- Investments that may be required in the short or medium term.
The energy performance certificate describes the situation taken into account when it was prepared. If work was completed later, it is important to check whether it appears in the document or must be assessed separately.
Is replacing the heating system enough to achieve a good rating?
Not necessarily. Replacing an old system with a more efficient installation can improve certain indicators, but the result also depends on the building’s energy requirements.
If the walls, roof, windows or airtightness have significant weaknesses, the building will continue to require substantial energy to maintain a comfortable temperature.
A coherent renovation must therefore consider all of the following:
- The thermal quality of the building envelope.
- The heating system.
- Domestic hot-water production.
- Ventilation.
- The technical compatibility of the different improvements.
Page 4: the building’s actual consumption
The fourth page is particularly useful when it has been completed properly. It can show actual consumption recorded during the years following preparation of the energy performance certificate.
This information makes it possible to compare the document’s theoretical calculations with the property’s actual use.
Theoretical and actual consumption: what is the difference?
Theoretical consumption is calculated using the building’s characteristics, its systems and standardised assumptions about use.
Actual consumption corresponds to what was genuinely consumed. It depends not only on the building, but also on the behaviour of its occupants.
Factors that can influence actual consumption
- The number of occupants.
- The preferred room temperature.
- The amount of time the property is occupied.
- Ventilation habits.
- Hot-water use.
- Whether all or only part of the heated area is used.
- Weather conditions during the period reviewed.
A property occupied by one person and heated moderately cannot be compared directly with a similar property occupied by a family maintaining a higher temperature.
Actual consumption is therefore not a guarantee of what the future owner will pay. It nevertheless provides an order of magnitude and can help buyers ask more precise questions.
Which additional documents should be requested?
Where possible, a buyer can ask to review recent heating bills or statements. They must be interpreted carefully, but they provide a practical complement to the energy performance certificate.
- Check the period covered by the documents.
- Identify the energy actually billed.
- Take the number of occupants into account.
- Ask whether every room was heated.
- Check whether any work changed consumption during the period reviewed.
Key Takeaway
Theoretical consumption helps compare the energy characteristics of different buildings. Actual consumption also reflects occupant behaviour. Both are useful, but they do not answer exactly the same question.
Page 5: recommendations and improvement potential
The fifth page is sometimes incomplete or reviewed too quickly. Yet it can be one of the most useful parts of the energy performance certificate.
It presents measures that may improve the building’s performance and can indicate the associated theoretical savings. When several improvements are considered, it may also provide an overview of the expected overall improvement.
Recommendations may notably concern
- Roof insulation.
- External-wall insulation.
- Insulation of floors or surfaces adjoining unheated areas.
- Window replacement.
- Improved airtightness.
- Installation or adaptation of a ventilation system.
- Replacement of the heating system.
- Integration of renewable-energy production.
The current rating is only part of the picture
When buyers compare several properties, they often focus on the current rating. This comparison is useful, but it may be insufficient.
Two houses rated F can have completely different prospects.
| Property | Current position | Potential after renovation |
|---|---|---|
| House A | Rated F, with several clearly identifiable weaknesses. | Coherent improvements could deliver a significant increase in performance. |
| House B | Rated F, with construction constraints that are more difficult to correct. | Major work might result in only limited improvement. |
Both properties have the same rating at the time of sale, but they do not have the same potential or necessarily the same appeal for a buyer planning a renovation.
Can every building reach the highest ratings?
No. Certain characteristics can limit the level of performance a building can reasonably achieve.
The potential depends notably on:
- The building’s original design.
- Its shape and compactness.
- The materials and construction techniques used.
- The possibility of insulating the different surfaces effectively.
- Thermal bridges that are difficult to eliminate.
- Architectural, planning or heritage constraints.
- The space available for new equipment.
- The budget required in relation to the actual improvement achieved.
In some cases, reaching an intermediate rating may be a technically coherent and economically reasonable objective. Systematically aiming for the highest possible rating is not always feasible or proportionate.
Key Takeaway
Two properties with the same energy rating can have completely different renovation potential. Not every building can reach the highest ratings, even after major work.
Why is this page useful to both buyers and sellers?
For a buyer, this page provides an indication of the property’s theoretical potential after renovation. It helps assess whether future investment could significantly improve the property’s energy performance.
For a seller, it can also provide a useful basis for discussion when work has already been completed or when a buyer wants to understand the building’s potential for improvement.
This page is neither a quotation nor a guarantee of results. Nevertheless, it provides valuable information for understanding the property’s scope for improvement.
How can the energy performance certificate affect a property’s value?
Energy performance carries increasing weight among the criteria buyers consider. Heating costs, future renovation work and thermal comfort are now common concerns during a property search.
However, it would be reductive to summarise a property’s value by its energy rating alone.
Many other factors continue to influence the price significantly:
- The property’s location.
- The size of the plot.
- The overall quality of construction.
- Its state of maintenance.
- Renovations already completed.
- Supply and demand in the local market.
The energy performance certificate is therefore one important factor among others. It helps clarify the property, but cannot determine its market value on its own.
Key Takeaway
The energy rating influences buyer perception, but improvement potential and the cost of the required work can sometimes matter just as much as the current rating.
How should the certificate be used during a viewing?
During a viewing, the energy performance certificate can provide a useful framework for asking relevant questions and understanding the building more clearly.
Useful questions to ask
- Was any work completed after the certificate was issued?
- Was the heating system replaced recently?
- Was the insulation improved after the document was issued?
- Is actual consumption data available?
- Have any recommendations in the certificate already been implemented?
- Which improvements are still possible?
The more precise the available information, the better a buyer can assess the property’s energy potential.
FAQ: Energy Performance Certificates in Luxembourg
Is an energy performance certificate required when selling a property?
Yes. A valid energy performance certificate is generally required when selling property in Luxembourg.
How long does an energy performance certificate remain valid?
The certificate has a limited validity period. Check the expiry date shown on the first page of the document.
Does a poor energy rating prevent a property from being sold?
No. Many properties with average or poor energy ratings are sold. Buyers usually consider many other factors, including location, the building’s overall condition and its improvement potential.
Why can actual consumption differ significantly from theoretical consumption?
Occupant habits, preferred temperatures, the number of people living in the property and the effective use of the rooms can significantly influence observed consumption.
Can every building reach an A or B rating?
No. Construction, technical or architectural characteristics can limit the performance a building can reasonably achieve, even after renovation.
Why is page 5 often one of the most important pages?
Because it helps clarify the building’s improvement potential. Two properties with the same current energy rating can have very different renovation prospects.
Our Local Expertise
BLImmo supports property owners and buyers in western Luxembourg, including Steinfort, Hobscheid, Koerich, Mamer, Kehlen, Capellen, Garnich, Eischen, Windhof and the surrounding municipalities.
When assessing a property, the energy performance certificate is one of several documents that help clarify its technical characteristics, potential and the questions buyers are likely to ask.
Sources and Further Information
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The energy performance certificate is a valuable tool for understanding a building, but it does not replace a comprehensive assessment of the property and its market.
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