What is the energy performance of buildings?

The notion of energy performance refers to the amount of energy consumed each year by a building. It varies according to the building, which is more or less energy-intensive, but also according to its operation and its energy equipment. The energy performance of buildings is a major issue in reducing energy consumption and greenhouse gas emissions.

From a concrete point of view, energy performance is one of the levers of the energy transition. Moreover, it is a relatively measurable data, in particular thanks to the introduction of the DPE (Diagnostic de Performance Énergétique).

Definition of the energy performance of buildings


The energy performance of a building is a data generally correlated to that of energy efficiency. While the latter refers to the ratio between the energy absorbed by the building and the energy consumed within it, energy performance is used as a benchmark to know the energy expenditure of the building over the year.

The notion of energy performance of buildings is commonly used in subjects related to the ecological and energy transition, or in the building and housing sectors. It allows the formulation of energy consumption reduction objectives and therefore the improvement of the energy efficiency of a building. Optimizing energy performance is therefore one of the major challenges of climate change.

Improving the energy performance of a building means acting on its energy consumption. The objective is to optimize its estimated energy consumption over the year while guaranteeing a certain level of thermal comfort. This is why the notion of energy performance is linked to that of energy efficiency. The two are interdependent.

performance énergétique des bâtiments

How is energy performance calculated?

The calculation of the energy performance of buildings is based on different criteria, relating to both the quantity of energy produced by a residential building and the quality of this energy. The qualitative criteria include heating systems, hot water, related equipment, ventilation and air conditioning systems.

Quantitative indicators complete these criteria. These are generally numerical data relating to all the technical characteristics of the building. To calculate its overall energy performance, it is necessary to take into account all the energy installations of the building, from its exposure to the sun to its thermal insulation, including the layout of the dwelling in relation to the climatic context in which it evolves.

It is the compilation of all these data that allows energy professionals to calculate the energy performance of a building. It is this result that leads to the formulation of the DPE (Diagnostic de Performance Energétique). The DPE allows in turn to visually locate the energy performance of the building via letters and colors. The more energy-efficient a home is, the closer the letter is to A.

Calculating the energy performance of buildings makes it possible to take into account its existing criteria in order to build several optimization strategies and anticipate the work to improve its energy efficiency, and to prepare for the upcoming transition, either towards energy savings targets or towards more ambitious energy production targets. The energy performance calculation is also an essential step in providing you with solutions to optimize your energy performance, if possible without having to plan any renovation work.

What regulations around energy performance?

Energy performance is also an active indicator within the framework of the new European environmental regulations in force to measure the level of energy consumption of buildings as well as the savings performed, particularly during the construction of new housing in the real estate sector.

The very notion of energy performance is linked to the introduction of thermal regulations, in particular the RT 2012, which had the BBC level as a reference value. In 2020, the regulation plans to move energy performance towards a passive energy or even positive energy building objective. The law supports the public project of encouraging more and more the use of renewable energies to promote energy savings in the tertiary sector.

To achieve this, the thermal regulation defines a level of energy performance to be reached. The number of KWh not to be exceeded depends on the building criteria. This energy limitation concerns the use of heating, air conditioning, hot water, lighting and auxiliary energy equipment such as heating pumps or VMC.

Although the regulations provide a framework for improving the energy performance of companies, this is linked to the objectives and requirements of each company. This implies working on energy use by the occupants. You can also approach a company offering an energy performance consulting service to set up a long-term energy saving strategy.