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In Paris, a good energy rating does not always guarantee a comfortable apartment during heatwaves. Floor level, orientation, roof insulation, shutters, ventilation and condominium rules are becoming essential criteria.
A good DPE rating does not guarantee that a Paris apartment will remain comfortable during a heatwave.
The French energy performance rating, from A to G, primarily provides information about a property's energy consumption and greenhouse gas emissions. The DPE also includes a separate summer comfort indicator, but this focuses on the passive behaviour of the property.
To assess how comfortable an apartment will actually be in July or August, buyers need to look further: at the floor level, the roof, the orientation of each room, solar protection, ventilation, external noise, the building's thermal inertia and the rules of the condominium.
In Paris, these factors are gradually becoming important criteria for buyers, affecting a property's attractiveness and, in some cases, price negotiations.
Fairway Luxury Real Estate, a specialist in luxury real estate in Paris, assists buyers and sellers with a comprehensive analysis of a property that goes beyond its energy rating, helping identify its genuine strengths and any potential constraints related to summer comfort.
Since its reform, the DPE has included an indicator designed to classify passive summer comfort as good, moderate or insufficient.
This indicator examines certain characteristics that may limit overheating, including insulation, solar protection, thermal inertia and the property's ability to be ventilated. It also provides recommendations for potential improvements.
However, it is important to distinguish between two separate pieces of information:
An apartment can therefore receive a satisfactory energy rating while still offering moderate or insufficient summer comfort.
Conversely, a property that performs less well in winter may have characteristics that are beneficial during hot weather, including strong thermal inertia, external shutters or cross ventilation.
The DPE is therefore an essential starting point, but it cannot replace a physical assessment of the property and its immediate environment.
Two apartments of the same size, located in the same arrondissement and with comparable DPE ratings can offer completely different experiences during a heatwave.
A top-floor apartment beneath a poorly insulated roof, facing south-west and without external solar protection will not behave in the same way as an apartment on an intermediate floor, with dual exposure, protected from direct sunlight and built with walls capable of slowing temperature changes.
The difference is not always visible during a viewing in February or early spring. It may become obvious after several consecutive days with temperatures above 30°C.
Top-floor apartments remain highly sought after in Paris for their natural light, quiet surroundings, views and terraces. They should not automatically be considered poor investments.
However, they require particular attention when the apartment is located directly beneath:
The quality of roof insulation, the presence of blinds or shutters, ceiling height and the ability to cool the apartment during the night can significantly change the way the property behaves during periods of intense heat.
A south-facing orientation remains highly desirable for natural light. It is not, by itself, a disadvantage.
However, it should be analysed together with:
A west or south-west exposure can be particularly challenging in the late afternoon. West-facing bedrooms may continue to release accumulated heat at bedtime, especially after several consecutive hot days.
It is therefore important to analyse the orientation of each room rather than focusing solely on the living room.
A dual-aspect or through apartment has openings on at least two different orientations or facades. This configuration can make it easier to create airflow, particularly when windows are opened during the coolest hours of the day.
By contrast, a single-aspect apartment may accumulate more heat when it receives significant direct sunlight and air circulation is limited.
A dual-aspect layout does not automatically guarantee a cool apartment. Its effectiveness also depends on wind conditions, the layout of the property, the size of the openings and whether windows can realistically remain open.
Night-time ventilation is one of the main ways to reduce the temperature of an apartment after a hot day.
However, this strategy can become difficult when the property faces:
A bedroom may be perfectly quiet with the windows closed but significantly less comfortable when they need to remain open throughout the night. External noise and thermal comfort should therefore be analysed together.
Insulation, thermal inertia and ventilation all contribute to summer comfort, but they do not play the same role.
Insulation limits heat transfer between the inside and outside of a property. It helps reduce heat loss in winter and can slow the entry of heat during summer.
However, insulation alone does not always prevent overheating. A well-insulated apartment may retain accumulated heat if solar exposure is significant and the temperature cannot fall sufficiently during the night.
Thermal inertia refers to the ability of a building's materials to absorb part of the heat and slow down temperature variations. Some older Parisian buildings with thick walls can therefore help moderate temperature peaks.
Ventilation, meanwhile, helps remove accumulated heat. Windows on different facades, the layout of the apartment, the performance of mechanical ventilation and external noise levels can all play an important role.
A comfortable apartment in summer therefore rarely depends on a single feature. It is the combination of these characteristics that determines how the property performs during periods of intense heat.
Certain types of properties deserve a more detailed analysis before purchase:
These characteristics do not mean that a property is unsellable or that it will automatically lose value.
The analysis must always consider the combination of the property's characteristics. A top-floor apartment with proper roof insulation, effective solar protection and a compliant air-conditioning system does not present the same profile as a top-floor property with no practical solution.
To assess the summer comfort of a Paris apartment, it is useful to follow a structured approach.
A second viewing can be particularly useful for a top-floor apartment, a family property or a home requiring a significant investment.
Air conditioning can improve the attractiveness of a highly exposed apartment, particularly when it is already installed, quiet, discreet and compliant.
However, it is not an automatic solution.
Before buying or selling an apartment equipped with air conditioning, it is important to check:
When an installation affects common areas or changes the external appearance of the building, approval from the condominium association is generally required.
An existing installation should therefore not be presented as a commercial advantage until its compliance has been properly documented.
Summer comfort primarily affects the use value of a property: the ability to sleep, work from home and live comfortably during periods of high temperatures.
Its precise impact on the sale price then depends on a wide range of characteristics:
It would therefore be unwise to apply an automatic discount to every top-floor apartment or a uniform premium to every air-conditioned property.
However, overheating that is difficult to correct can lead to hesitation during a viewing, requests for additional technical assessments, stronger price negotiations or a preference for a competing property.
Conversely, a seller who can document roof insulation, solar protection, ventilation or the compliance of an air-conditioning system can significantly reduce uncertainty for potential buyers.
Summer comfort should no longer be treated as a minor detail or an objection to avoid discussing.
Depending on the characteristics of the property, a seller should consider preparing documentation including:
When a property receives significant direct sunlight, it is generally better to explain the solutions already in place rather than deny the possibility of overheating. A transparent presentation helps maintain the buyer's confidence and prevents a late discovery from becoming a negotiating point.
Buyers should not simply look for a bright apartment. They should look for a property capable of remaining comfortable and usable throughout the year.
It is important to distinguish between:
For family apartments, top-floor properties and luxury homes, analysing the bedrooms is particularly important. An air-conditioned living room does not necessarily solve the issue of bedroom temperatures at night.
For new buildings, France's RE2020 environmental regulations already use an indicator expressed in degree-hours of discomfort. This measures both the duration and intensity of periods during which indoor temperatures are considered uncomfortable.
For existing properties, the issue is also becoming increasingly important in public discussions and in the expectations of buyers.
The real estate market may begin to integrate this evolution even before the introduction of a new official rating or regulatory obligation.
Buyers are already asking very practical questions:
The DPE remains essential, but the quality of an apartment can no longer be reduced to a single letter. In Paris, its ability to remain comfortable in both winter and summer is likely to become an increasingly important part of its overall value.
Does a good DPE rating guarantee a cool apartment in summer?
No. The A to G energy rating and the summer comfort indicator are two separate pieces of information. A property with a strong energy rating may still offer moderate or insufficient summer comfort depending on its orientation, floor level, solar protection and ability to be ventilated.
How can you tell if an apartment will overheat?
You should examine the floor level, the roof, the orientation of the bedrooms, the size of glazed surfaces, solar protection and the possibility of ventilating the property at night. A late-afternoon viewing can be particularly revealing for a west-facing apartment.
Is a south-facing apartment a bad choice?
No. A south-facing orientation can provide excellent natural light and remain comfortable when the property has effective solar protection, good thermal inertia and efficient ventilation. It should be assessed together with the other characteristics of the apartment.
Will top-floor apartments lose value?
Not necessarily. They remain highly desirable for their light, views, quiet surroundings and outdoor spaces. However, buyers are likely to pay closer attention to roof insulation, solar protection, bedroom temperatures and the possibility of installing an effective cooling solution.
Does air conditioning increase an apartment's value?
A compliant and well-integrated air-conditioning system can improve the attractiveness of a highly exposed property and reduce certain buyer concerns. However, there is no automatic price premium, as its impact depends on the local market, the type of property and comparable transactions.
Can you freely install air conditioning in a Paris condominium?
Not always. You should review the condominium regulations and determine whether the installation affects common areas or changes the external appearance of the building. In these situations, approval from the condominium association may be required.
What should a seller prepare?
A seller should gather documentation relating to the DPE, shutters, blinds, insulation, the roof and any air-conditioning system. Condominium meeting minutes and relevant approvals should also be reviewed to provide clear and accurate answers to buyers' questions.
Key points to remember
"The DPE remains essential, but it does not tell the whole story of how a property actually feels to live in. In Paris, summer comfort is becoming a genuine real estate criterion: an apartment should also be assessed on its ability to remain comfortable when high temperatures persist for several days."
 | Author of the article Hugues de Poulpiquet Fairway Luxury Real Estate · Real Estate Market Trained as a lawyer and founder of Fairway Luxury Real Estate, Hugues de Poulpiquet writes Fairway's market insights dedicated to the Paris real estate market, sales strategies and the valuation of high-end residential properties. |
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