The energy performance corresponds to the amount of energy consumed each year to operate a building. It is calculated from the main characteristics of the building, such as its heating and hot water systems and its related energy equipment.
The energy performance is an extremely relevant criterion to optimize the energy efficiency of the building. It is represented by the energy performance diagnosis, the DPE. The latter evaluates its energy consumption and its level of greenhouse gas emissions.
A diagnosis governed by European regulations
If you can perform an energy audit of your buildings with a professional, it does not necessarily mean that it is an energy performance diagnosis. Indeed, the performance of an ECD is regulated by the European Union.
The energy performance diagnosis must focus on an exhaustive description of the building. It indicates its surface, its orientation, the nature of the walls and windows, and provides information on the materials used. It also focuses on the equipment, especially regarding ventilation and heating, as well as the hot water production system.
Depending on the framework of the request, the energy performance diagnosis indicates the amount of energy actually consumed based on the tenant’s or owner’s bills, or the estimated amount of energy spent based on a standard use of the building.
As energy performance is closely linked to environmental performance, its calculation is concerned with the impact of the house on the environment. This is why greenhouse gas emissions are taken into account as a priority in the calculation of the energy performance of buildings.
Energy performance indicators
Some indicators are a priority in the calculations to estimate the performance of buildings. To calculate the actual energy consumption of a building, the diagnostician takes into account thermal characteristics, including the average heating temperature. It is obvious that this depends on the uses of the dwelling, in particular the amount of energy spent by the users, and that the optimization of energy efficiency necessarily involves energy savings.
The calculation of the energy performance allows to compare as objectively as possible the energy quality of a building stock, for example. The diagnosis also has the role of providing advice to the buyer or owner. These recommendations should help him to follow a good use of the housing and its equipment to improve its energy performance.
This advice can lead to a set of recommendations for work, generally renovation or optimization of insulation. These works are in no way mandatory. It is even possible to increase the energy performance of a building without performing any work.
Choose a diagnostician to evaluate your energy performance
The DPE has been made compulsory in the following cases: construction of new buildings, sale of a dwelling or tertiary building, and rental of a dwelling. The 3 cases impose different calculation methods. Similarly, real estate advertisements must include the display of energy performance.
How to establish an energy performance diagnosis? First of all, the evaluation must be carried out by a professional whose skills meet the new European directive governing the DPE. You can contact a diagnostician through a real estate intermediary or a notary.
The diagnostician is required to take out insurance to cover his liability as a result of his work. He must also be independent and impartial with regard to the client of the DPE, but also with regard to the companies that may intervene in the house to perform work.